Antarctica

Abstract Recent measurements of snow accumulation on undulating surfaces around “Byrd station”, Antarctica indicate that the undulations are tending to be filled in. These results are discussed in the light of current knowledge of the origin and migration of such features.

@article{doi101017s0022143000018906,
    author = "Gow, Anthony J. and Rowland, Robert W.",
    title = "On the Relationship of Snow Accumulation to Surface Topography at “Byrd Station”, Antarctica",
    year = "1965",
    journal = "Journal of Glaciology",
    abstract = "Abstract Recent measurements of snow accumulation on undulating surfaces around “Byrd station”, Antarctica indicate that the undulations are tending to be filled in. These results are discussed in the light of current knowledge of the origin and migration of such features.",
    url = "https://doi.org/10.1017/s0022143000018906",
    doi = "10.1017/s0022143000018906",
    openalex = "W2468832152"
}

The Antarctic ice sheet at Byrd Station has been core-drilled to bedrock; the vertical thickness of the ice is 2164 meters. Liquid water-indicative of pressure melting-was encountered at the bed. Heat flow through the base of the ice sheet is estimated at 1.8 microcalories per square centimeter per second. The minimum temperature was -28.8 degrees C at 800 meters; maximum ice density, 0.9206 at 1000 meters. Core studies reveal the existence of a chemically pure, structurally stratified sheet comprising bubbly ice to 900 meters that transforms to bubble-free deformed ice, with substantially vertically orientated c-axis structure, below 1200 meters. Below 1800 meters the deformed ice structure gives way to large annealed crystals. Several thin layers of dirt between 1300 and 1700 meters are tentatively identified as volcanic ash, and horizontally banded debris, including fragments of granite, is present in the basal ice.

@article{doi101126science16138451011,
    author = "Gow, Anthony J. and Ueda, Herbert T. and Garfield, Donald E.",
    title = "Antarctic Ice Sheet: Preliminary Results of First Core Hole to Bedrock",
    year = "1968",
    journal = "Science",
    abstract = "The Antarctic ice sheet at Byrd Station has been core-drilled to bedrock; the vertical thickness of the ice is 2164 meters. Liquid water-indicative of pressure melting-was encountered at the bed. Heat flow through the base of the ice sheet is estimated at 1.8 microcalories per square centimeter per second. The minimum temperature was -28.8 degrees C at 800 meters; maximum ice density, 0.9206 at 1000 meters. Core studies reveal the existence of a chemically pure, structurally stratified sheet comprising bubbly ice to 900 meters that transforms to bubble-free deformed ice, with substantially vertically orientated c-axis structure, below 1200 meters. Below 1800 meters the deformed ice structure gives way to large annealed crystals. Several thin layers of dirt between 1300 and 1700 meters are tentatively identified as volcanic ash, and horizontally banded debris, including fragments of granite, is present in the basal ice.",
    url = "https://doi.org/10.1126/science.161.3845.1011",
    doi = "10.1126/science.161.3845.1011",
    openalex = "W1985049759",
    references = "doi101017s0022143000018906, doi101017s0022143000028367, doi101017s0022143000030975, doi10108014786436208209120, doi10113000167606196273877porfmi20co2, doi103189s0022143000028367, doi103189s0022143000030975"
}

Oxygen- and hydrogen-isotope analyses from the core hole through the Antarctic Ice Sheet at Byrd Station define temperature variations over more than 75,000 years. Synchronism between major climatic changes in Antarctica and the Northern Hemisphere is strongly indicated. The Wisconsin cold interval extended from 75,000 to 11,000 years ago. Three intra-Wisconsin warmer phases were all colder than pre- or post-Wisconsin times, which suggests that North American and Eurasian continental ice sheets did not disappear at any time during the Wisconsin.

@article{epstein1970antarctic,
    author = "Epstein, Samuel and Sharp, R. P. and Gow, A. J.",
    title = "Antarctic Ice Sheet: Stable Isotope Analyses of Byrd Station Cores and Interhemispheric Climatic Implications",
    year = "1970",
    journal = "Science",
    abstract = "Oxygen- and hydrogen-isotope analyses from the core hole through the Antarctic Ice Sheet at Byrd Station define temperature variations over more than 75,000 years. Synchronism between major climatic changes in Antarctica and the Northern Hemisphere is strongly indicated. The Wisconsin cold interval extended from 75,000 to 11,000 years ago. Three intra-Wisconsin warmer phases were all colder than pre- or post-Wisconsin times, which suggests that North American and Eurasian continental ice sheets did not disappear at any time during the Wisconsin.",
    url = "https://doi.org/10.1126/science.168.3939.1570",
    doi = "10.1126/science.168.3939.1570",
    number = "3939",
    openalex = "W2044683518",
    pages = "1570-1572",
    volume = "168",
    references = "doi1010160016703753900519, doi101017s0022143000028367, doi101017s0022143000031208, doi101029jb073i008p02691, doi101086627150, doi101126science1253240182, doi101126science16138451011, doi1023071796130, doi103189s0022143000028367, doi103189s0022143000031208"
}

@techreport{blank1975pliocene1,
    author = "Blank, R. G. and Margolis, S. V",
    title = "Pliocene climatic and glacial history of Antarctica as revealed by southeast Indian Ocean deep-sea cores",
    year = "1975",
    howpublished = "Geological Society of America Bulletin, v. 86, p. 1058-1066",
    note = "talkorigins\_source = {true}; raw\_reference = {Blank, R. G., and Margolis, S. V., 1975, Pliocene climatic and glacial history of Antarctica as revealed by southeast Indian Ocean deep-sea cores: Geological Society of America Bulletin, v. 86, p. 1058-1066.}"
}

The concentration of microparticles in the 216 4 m long ice core from “Byrd” station Antarctica, varies cyclically. Highest concentrations of 0.65 μm diameter microparticles occur where oxygen-isotope studies show lowest paleotemperatures. The age of the bottom ice estimated from microparticle-concentration variations, assuming an annual cycle, is 27 000 years, much less than from oxygen-isotope studies.

@article{doi101017s0022143000021948,
    author = "Thompson, Lonnie G. and Hamilton, Wayne L. and Bull, C.",
    title = "Climatological, Implications of Microparticle Concentrations in the Ice Core From “Byrd” Station, Western Antarctica",
    year = "1975",
    journal = "Journal of Glaciology",
    abstract = "The concentration of microparticles in the 216 4 m long ice core from “Byrd” station Antarctica, varies cyclically. Highest concentrations of 0.65 μm diameter microparticles occur where oxygen-isotope studies show lowest paleotemperatures. The age of the bottom ice estimated from microparticle-concentration variations, assuming an annual cycle, is 27 000 years, much less than from oxygen-isotope studies.",
    url = "https://doi.org/10.1017/s0022143000021948",
    doi = "10.1017/s0022143000021948",
    openalex = "W4241017141",
    references = "doi1010160012821x67900623, doi1010160012821x71901269, doi101017s0022143000013423, doi101017s0022143000027386, doi101038235429a0, doi101098rsta19700010, doi101126science16138451011, doi101126science1663903377, doi101126science1733992138, epstein1970antarctic"
}

The concentration of microparticles in the 2 164 m long ice core from “Byrd” station Antarctica, varies cyclically. Highest concentrations of 0.65 μm diameter microparticles occur where oxygen-isotope studies show lowest paleotemperatures. The age of the bottom ice estimated from microparticle-concentration variations, assuming an annual cycle, is 27 000 years, much less than from oxygen-isotope studies.

@article{thompson1975climatological,
    author = "Thompson, Lonnie G. and Hamilton, Wayne L. and Bull, Colin",
    title = "Climatological, Implications of Microparticle Concentrations in the Ice Core From “Byrd” Station, Western Antarctica",
    year = "1975",
    journal = "Journal of Glaciology",
    abstract = "The concentration of microparticles in the 2 164 m long ice core from “Byrd” station Antarctica, varies cyclically. Highest concentrations of 0.65 μm diameter microparticles occur where oxygen-isotope studies show lowest paleotemperatures. The age of the bottom ice estimated from microparticle-concentration variations, assuming an annual cycle, is 27 000 years, much less than from oxygen-isotope studies.",
    url = "https://doi.org/10.3189/s0022143000021948",
    doi = "10.3189/s0022143000021948",
    number = "72",
    openalex = "W2586674038",
    pages = "433-444",
    volume = "14",
    references = "doi1010160012821x71901269, doi101016s0074614208x60450, doi101017s0022143000027386, doi101038235429a0, doi101098rsta19700010, doi101126science16138451011, doi101126science1663903377, doi101126science1733992138, doi1011751520046919620190474nisaic20co2, epstein1970antarctic"
}

@article{thompson1975climatological3,
    author = "Thompson, L. G. and Hamilton, W. L. and Bull, C",
    title = {Climatological implications of microparticle concentrations in the ice core from "Byrd" Station, western Antarctica},
    year = "1975",
    journal = "Journal of Glaciology, v. 14, p. 433-444",
    note = {talkorigins\_source = {true}; raw\_reference = {Thompson, L. G., Hamilton, W. L., and Bull, C., 1975, Climatological implications of microparticle concentrations in the ice core from "Byrd" Station, western Antarctica: Journal of Glaciology, v. 14, p. 433-444.}}
}

@article{doi101130001676061976871665riotis20co2,
    author = "Gow, Anthony J. and Williamson, Terrence",
    title = "Rheological implications of the internal structure and crystal fabrics of the West Antarctic ice sheet as revealed by deep core drilling at Byrd Station",
    year = "1976",
    journal = "Geological Society of America Bulletin",
    url = "https://doi.org/10.1130/0016-7606(1976)87<1665:riotis>2.0.co;2",
    doi = "10.1130/0016-7606(1976)87<1665:riotis>2.0.co;2",
    openalex = "W1995538662"
}

@article{doi1010160377027378900148,
    author = "Kyle, Philip R. and Jezek, P. A.",
    title = "Compositions of three tephra layers from the byrd station ice core, antarctica",
    year = "1978",
    journal = "Journal of Volcanology and Geothermal Research",
    url = "https://doi.org/10.1016/0377-0273(78)90014-8",
    doi = "10.1016/0377-0273(78)90014-8",
    openalex = "W1964352595"
}

@article{kyle1981tephra,
    author = "Kyle, Philip R. and Jezek, Peter A. and Mosley-Thompson, Ellen and Thompson, Lonnie G.",
    title = "Tephra layers in the Byrd Station ice core and the Dome C ice core, Antarctica and their climatic importance",
    year = "1981",
    journal = "Journal of Volcanology and Geothermal Research",
    url = "https://doi.org/10.1016/0377-0273(81)90073-1",
    doi = "10.1016/0377-0273(81)90073-1",
    number = "1",
    openalex = "W2084320826",
    pages = "29-39",
    volume = "11",
    references = "doi1010160012821x71901269, doi1010160377027378900148, doi101017s0032247400063804, doi101029jc081i006p01071, doi101029jz069i002p00341, doi101038280644a0, doi101126science16138451011, doi1023071796425, doi102475ajs2589664, epstein1970antarctic"
}

@misc{kerr1982new2,
    author = "Kerr, R. A",
    title = "New evidence fuels Antarctic ice debate",
    year = "1982",
    howpublished = "Science, v. 216, p. 973-974",
    note = "talkorigins\_source = {true}; raw\_reference = {Kerr, R. A., 1982, New evidence fuels Antarctic ice debate: Science, v. 216, p. 973-974.}"
}

Five long-term oxygen isotope (δ) records along ice cores are discussed, in particular two from the Greenland ice sheet that exhibit persistent δ oscillations with a quasi-periodicity of ca. 2550 years. A detailed study of the δ cycles in the Wisconsin glaciation show that they cannot be ascribed to discontinuities in the cores, nor to ice-dynamic instabilities in the ice sheet. In the Holocene, the δ cycles are less pronounced, but they are concurrent with the fluctuating glacier extention elsewhere, which substantiates their climatic significance. An anti-correlation with 14C concentration in atmospheric CO2, and with 10Be deposition rates on the ice sheets, suggests a connection between climate and solar processes, but a conclusion on this point must await clarification of the terrestrial circulation and mixing processes, and the relationship between the solar outputs of radiation and particulate matter.

@incollection{doi101029gm029p0288,
    author = "Dansgaard, W. and Johnsen, S. J. and Clausen, Henrik and Dahl‐Jensen, Dorthe and Gundestrup, N. and Hammer, C. U. and Oeschger, H.",
    title = "North Atlantic climatic oscillations revealed by deep Greenland ice cores",
    year = "1984",
    booktitle = "Geophysical monograph",
    abstract = "Five long-term oxygen isotope (δ) records along ice cores are discussed, in particular two from the Greenland ice sheet that exhibit persistent δ oscillations with a quasi-periodicity of ca. 2550 years. A detailed study of the δ cycles in the Wisconsin glaciation show that they cannot be ascribed to discontinuities in the cores, nor to ice-dynamic instabilities in the ice sheet. In the Holocene, the δ cycles are less pronounced, but they are concurrent with the fluctuating glacier extention elsewhere, which substantiates their climatic significance. An anti-correlation with 14C concentration in atmospheric CO2, and with 10Be deposition rates on the ice sheets, suggests a connection between climate and solar processes, but a conclusion on this point must await clarification of the terrestrial circulation and mixing processes, and the relationship between the solar outputs of radiation and particulate matter.",
    url = "https://doi.org/10.1029/gm029p0288",
    doi = "10.1029/gm029p0288",
    openalex = "W1491826018",
    references = "doi101038266508a0"
}

@article{angelis1987aerosol,
    author = "Angelis, M. De and Barkov, N. I. and Petrov, V. N.",
    title = "Aerosol concentrations over the last climatic cycle (160 kyr) from an Antarctic ice core",
    year = "1987",
    journal = "Nature",
    url = "https://doi.org/10.1038/325318a0",
    doi = "10.1038/325318a0",
    number = "6102",
    openalex = "W2024795556",
    pages = "318-321",
    volume = "325",
    references = "doi1010160012825276900088, doi1010160016703764901292, doi1010160033589473900525, doi101038272043a0, doi101038293391a0, doi101038316591a0, doi10113000167606197081189eadasa20co2, doi1011751520046919670240472thyoim20co2, openalexw2916805370, openalexw593191868"
}

@article{doi1010160004698188900376,
    author = "Legrand, Michel and Lorius, C. and Barkov, N. I. and Petrov, V. N.",
    title = "Vostok (Antarctica) ice core: Atmospheric chemistry changes over the last climatic cycle (160,000 years)",
    year = "1988",
    journal = "Atmospheric Environment (1967)",
    url = "https://doi.org/10.1016/0004-6981(88)90037-6",
    doi = "10.1016/0004-6981(88)90037-6",
    openalex = "W2016341099",
    references = "doi101029jd090id07p12901, palais1985soluble"
}

A comprehensive glaciochemical study has been conducted at several Antarctic locations on the Antarctic plateau (South Pole Station, Dome C) and in more coastal regions (a few stations of Terre Adélie, East Antarctica). The objective was to investigate the sulfur, nitrogen, and halogen atmospheric cycles in very remote areas. In this paper the spatio‐temporal variations of the Cl/Na ratio are reported for several hundred samples collected in snow pits or from firn and ice cores using contamination‐free techniques. The Cl/Na weight ratio in snow is generally very close to that of bulk seawater (1.8) near the coast and begins to increase at the edge of the Antarctic plateau. In central areas, both relatively high and very low values are observed (excess chloride or excess sodium with respect to the 1.8 reference value), depending on the time period. Determination of all major ions (not fully reported in the present work) has provided an in‐depth understanding of the chemical composition of Antarctic precipitation, explaining excess chloride and excess sodium by the presence in snow of HCl or Na 2 SO 4, respectively, formed by the reaction of excess sulfate (biogenic H 2 SO 4) with sea‐salt particles in the aerosol phase. This reaction results in the release of gaseous HCl into the atmosphere. Short‐term (seasonal) or long‐term (climatic) variations observed in the sequences analyzed suggest that this reaction occurs more completely when weather conditions are calm and marine aerosol is aged. In central areas this alteration of marine aerosol can lead to excess chloride of up to 50% of total chloride deposition, and Na 2 SO 4 can be equivalent to the sulfuric acid deposition. These results demonstrate the importance of the interaction between sulfur and chlorine cycles in the Antarctic atmosphere.

@article{doi101029jd093id06p07153,
    title = "Formation of HCl in the Antarctic atmosphere",
    year = "1988",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "A comprehensive glaciochemical study has been conducted at several Antarctic locations on the Antarctic plateau (South Pole Station, Dome C) and in more coastal regions (a few stations of Terre Adélie, East Antarctica). The objective was to investigate the sulfur, nitrogen, and halogen atmospheric cycles in very remote areas. In this paper the spatio‐temporal variations of the Cl/Na ratio are reported for several hundred samples collected in snow pits or from firn and ice cores using contamination‐free techniques. The Cl/Na weight ratio in snow is generally very close to that of bulk seawater (1.8) near the coast and begins to increase at the edge of the Antarctic plateau. In central areas, both relatively high and very low values are observed (excess chloride or excess sodium with respect to the 1.8 reference value), depending on the time period. Determination of all major ions (not fully reported in the present work) has provided an in‐depth understanding of the chemical composition of Antarctic precipitation, explaining excess chloride and excess sodium by the presence in snow of HCl or Na 2 SO 4, respectively, formed by the reaction of excess sulfate (biogenic H 2 SO 4) with sea‐salt particles in the aerosol phase. This reaction results in the release of gaseous HCl into the atmosphere. Short‐term (seasonal) or long‐term (climatic) variations observed in the sequences analyzed suggest that this reaction occurs more completely when weather conditions are calm and marine aerosol is aged. In central areas this alteration of marine aerosol can lead to excess chloride of up to 50\% of total chloride deposition, and Na 2 SO 4 can be equivalent to the sulfuric acid deposition. These results demonstrate the importance of the interaction between sulfur and chlorine cycles in the Antarctic atmosphere.",
    url = "https://doi.org/10.1029/jd093id06p07153",
    doi = "10.1029/jd093id06p07153",
    openalex = "W2091445981",
    references = "doi101029jd090id07p12901, palais1985soluble"
}

Three ice cores to bedrock from the Dunde ice cap on the north-central Qinghai-Tibetan Plateau of China provide a detailed record of Holocene and Wisconsin-Würm late glacial stage (LGS) climate changes in the subtropics. The records reveal that LGS conditions were apparently colder, wetter, and dustier than Holocene conditions. The LGS part of the cores is characterized by more negative delta(18)O ratios, increased dust content, decreased soluble aerosol concentrations, and reduced ice crystal sizes than the Holocene part. These changes occurred rapidly approximately 10,000 years ago. In addition, the last 60 years were apparently one of the warmest periods in the entire record, equalling levels of the Holocene maximum between 6000 and 8000 years ago.

@article{doi101126science2464929474,
    author = "Thompson, Lonnie G. and Mosley‐Thompson, Ellen and Davis, M. E. and Bolzan, John F. and Dai, J. and Klein, L. and Yao, Tandong and Wu, X. and Xie, Zhouqing and Gundestrup, N.",
    title = "Holocene—Late Pleistocene Climatic Ice Core Records from Qinghai-Tibetan Plateau",
    year = "1989",
    journal = "Science",
    abstract = "Three ice cores to bedrock from the Dunde ice cap on the north-central Qinghai-Tibetan Plateau of China provide a detailed record of Holocene and Wisconsin-Würm late glacial stage (LGS) climate changes in the subtropics. The records reveal that LGS conditions were apparently colder, wetter, and dustier than Holocene conditions. The LGS part of the cores is characterized by more negative delta(18)O ratios, increased dust content, decreased soluble aerosol concentrations, and reduced ice crystal sizes than the Holocene part. These changes occurred rapidly approximately 10,000 years ago. In addition, the last 60 years were apparently one of the warmest periods in the entire record, equalling levels of the Holocene maximum between 6000 and 8000 years ago.",
    url = "https://doi.org/10.1126/science.246.4929.474",
    doi = "10.1126/science.246.4929.474",
    openalex = "W1967851076",
    references = "angelis1987aerosol, doi1010160012821x80901703, doi1010160031018286901197, doi101017s0022143000030288, doi101029jc082i027p03889, doi101029jd093id08p09341, doi101038235429a0, doi101038266508a0, doi101038280644a0, doi101126science19142321138, doi101126science2274688721"
}

This POSTnote reviews the Antarctic Treaty System with emphasis on scientific activities relevant to the current debate

@misc{crossref1990antarctica,
    title = "Antarctica",
    year = "1990",
    abstract = "This POSTnote reviews the Antarctic Treaty System with emphasis on scientific activities relevant to the current debate",
    url = "https://doi.org/10.58248/pn018",
    doi = "10.58248/pn018"
}

Human activities have already modified the chemical composition of the natural atmosphere even in very remote regions of the world. The study of chemical parameters stored in solid precipitation and accumulated on polar ice sheets over the last several hundred thousand years provides a unique tool for obtaining information on the composition of the preindustrial atmosphere and its natural variability over the past. This paper deals with the chemistry of polar ice focused on the soluble mineral (Na +, NH 4 +, K +, Ca ++, Mg ++, H +, F −, Cl −, NO 3 −, SO 4 −−, and H 2 O 2) and organic (methanesulfonate (CH 3 SO 3 −), formate (HCOO −), acetate (CH 3 COO −), and formaldehyde (HCHO)) species and their interpretation in terms of past atmospheric composition (aerosols and water soluble gaseous species). We discuss ice core dating, the difficulties connected with trace measurements, and the significance of the ionic composition of snow. We examine temporal (from the last decades back to the last climatic cycle) and spatial (including examples from coastal as well as central areas of Greenland and Antarctica) variations in the ionic budget of the precipitation and evaluate ice core studies in terms of the chemical composition of our past atmosphere. We review (1) how Greenland and Antarctic ice cores that span the last few centuries have provided information on the impact of human activities and (2) how the chemistry of deep ice cores provides information on various past natural phenomena such as climatic variations (glacial‐interglacial changes, El Niño), volcanic eruptions, and large boreal forest fires.

@article{doi10102996rg03527,
    author = "Legrand, Michel and Mayewski, Paul A.",
    title = "Glaciochemistry of polar ice cores: A review",
    year = "1997",
    journal = "Reviews of Geophysics",
    abstract = "Human activities have already modified the chemical composition of the natural atmosphere even in very remote regions of the world. The study of chemical parameters stored in solid precipitation and accumulated on polar ice sheets over the last several hundred thousand years provides a unique tool for obtaining information on the composition of the preindustrial atmosphere and its natural variability over the past. This paper deals with the chemistry of polar ice focused on the soluble mineral (Na +, NH 4 +, K +, Ca ++, Mg ++, H +, F −, Cl −, NO 3 −, SO 4 −−, and H 2 O 2) and organic (methanesulfonate (CH 3 SO 3 −), formate (HCOO −), acetate (CH 3 COO −), and formaldehyde (HCHO)) species and their interpretation in terms of past atmospheric composition (aerosols and water soluble gaseous species). We discuss ice core dating, the difficulties connected with trace measurements, and the significance of the ionic composition of snow. We examine temporal (from the last decades back to the last climatic cycle) and spatial (including examples from coastal as well as central areas of Greenland and Antarctica) variations in the ionic budget of the precipitation and evaluate ice core studies in terms of the chemical composition of our past atmosphere. We review (1) how Greenland and Antarctic ice cores that span the last few centuries have provided information on the impact of human activities and (2) how the chemistry of deep ice cores provides information on various past natural phenomena such as climatic variations (glacial‐interglacial changes, El Niño), volcanic eruptions, and large boreal forest fires.",
    url = "https://doi.org/10.1029/96rg03527",
    doi = "10.1029/96rg03527",
    openalex = "W1972471355",
    references = "doi1010160016703764901292, doi1010160016703779900590, doi101017s002214300001844x, doi101029jc087ic02p01231, doi101038333134a0, doi101038362527a0, doi101038364218a0, doi101038366552a0, doi101098rsta19700010, doi101111j215334901964tb00181x, doi101126science24148691043, hammer1994electrical, openalexw1564144063"
}

Over 70,000 samples from the 3029‐m‐long Greenland Ice Core Project (GRIP) ice core drilled on the top of the Greenland Ice Sheet (Summit) have been analyzed for δ 8 O. A highly detailed and continuous δ 8 O profile has thus been obtained and is discussed in terms of past temperatures in Greenland. We also discuss a three‐core stacked annual δ 8 O profile for the past 917 years. The short‐term (<50 years) variability of the annual δ 8 O signal is found to be 1‰ in the Holocene, and estimates for the coldest parts of the last glacial are 3‰ or higher. These data also provide insights into possible disturbances of the stratigraphic layering in the core which seems to be sound down to the onset of the Eemian. Spectral analysis of highly detailed sequences of the profile helps determine the smoothing of the δ 8 O signal, which for the Holocene ice is found to be considerably stronger than expected. We suggest this is due to a process involving diffusion of water molecules along crystal boundaries in the recrystallizing ice matrix. Deconvolution techniques were employed for restoring with great confidence the highly attenuated annual δ 8 O signal in the Holocene. We confirm earlier findings of dramatic temperature changes in Greenland during the last glacial cycle. Abrupt and strong climatic shifts are also found within the Eem/Sangamon Interglaciation, which is normally recorded as a period of warm and stable climate in lower latitudes. The stratigraphic continuity of the Eemian layers is consequently discussed in section 3 of this paper in terms of all pertinent data which we are not able to reconcile.

@article{doi10102997jc00167,
    author = "Johnsen, S. J. and Clausen, Henrik and Dansgaard, W. and Gundestrup, N. and Hammer, C. U. and Andersen, Uffe Brandt and Andersen, K. K. and Hvidberg, Christine S. and Dahl‐Jensen, Dorthe and Steffensen, J. P. and Shoji, Hitoshi and Sveinbjörnsdóttir, Árný E. and White, J. W. C. and Jouzel, Jean and Fisher, David",
    title = "The δ 18 O record along the Greenland Ice Core Project deep ice core and the problem of possible Eemian climatic instability",
    year = "1997",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "Over 70,000 samples from the 3029‐m‐long Greenland Ice Core Project (GRIP) ice core drilled on the top of the Greenland Ice Sheet (Summit) have been analyzed for δ 8 O. A highly detailed and continuous δ 8 O profile has thus been obtained and is discussed in terms of past temperatures in Greenland. We also discuss a three‐core stacked annual δ 8 O profile for the past 917 years. The short‐term (<50 years) variability of the annual δ 8 O signal is found to be 1‰ in the Holocene, and estimates for the coldest parts of the last glacial are 3‰ or higher. These data also provide insights into possible disturbances of the stratigraphic layering in the core which seems to be sound down to the onset of the Eemian. Spectral analysis of highly detailed sequences of the profile helps determine the smoothing of the δ 8 O signal, which for the Holocene ice is found to be considerably stronger than expected. We suggest this is due to a process involving diffusion of water molecules along crystal boundaries in the recrystallizing ice matrix. Deconvolution techniques were employed for restoring with great confidence the highly attenuated annual δ 8 O signal in the Holocene. We confirm earlier findings of dramatic temperature changes in Greenland during the last glacial cycle. Abrupt and strong climatic shifts are also found within the Eem/Sangamon Interglaciation, which is normally recorded as a period of warm and stable climate in lower latitudes. The stratigraphic continuity of the Eemian layers is consequently discussed in section 3 of this paper in terms of all pertinent data which we are not able to reconcile.",
    url = "https://doi.org/10.1029/97jc00167",
    doi = "10.1029/97jc00167",
    openalex = "W2082284070",
    references = "doi101038266508a0"
}

The size distribution of insoluble microparticles (dust) in the particle size interval 0.4–6.0 μm radius has been measured in more than 1400 samples from the Greenland Ice Core Project (GRIP) deep ice core from Summit, Greenland. The samples were taken from ice core segments representing 32 climatic periods including ice from the Eem interglacial and ice from below the Eemian ice. The mean dust volume distributions from the climatic periods are compared, and the relationship of total dust mass to the concentration of Ca 2+ and to the stable isotopic composition (δ 18 O) is investigated. The dust volume distributions are found to be lognormal in the size interval 0.4–2.0 μm with nearly identical shapes. Changes of the lognormal part of the volume distributions are found to be connected to the total dust mass in a systematic way. The total dust mass is correlated to the Ca 2+ concentration, and data do not show any enrichment in Ca 2+ from exposed continental shelves due to lower sea levels during the last glacial maximum. The total dust mass is strongly connected to δ 18 O. The volume distribution of the particles in the size interval 2.0–6.0 μm is found to be almost the same in most periods. The exceptions are the “cold” periods in the last part of the last glacial period, where the volume of these particles is higher than in most periods, and the periods from the Eemian and just above the Eemian where the volume of these particles is lower. The volume distributions of both the Eemian “warm” periods and the “cold” Eemian events are different from the distributions in ice from both below and above the Eemian ice. Climate changes appear to have modified the processes of production, transport, modification, and deposition of the dust aerosol in the same way over the last 120,000 years or more.

@article{doi10102997jc01490,
    author = "Steffensen, J. P.",
    title = "The size distribution of microparticles from selected segments of the Greenland Ice Core Project ice core representing different climatic periods",
    year = "1997",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "The size distribution of insoluble microparticles (dust) in the particle size interval 0.4–6.0 μm radius has been measured in more than 1400 samples from the Greenland Ice Core Project (GRIP) deep ice core from Summit, Greenland. The samples were taken from ice core segments representing 32 climatic periods including ice from the Eem interglacial and ice from below the Eemian ice. The mean dust volume distributions from the climatic periods are compared, and the relationship of total dust mass to the concentration of Ca 2+ and to the stable isotopic composition (δ 18 O) is investigated. The dust volume distributions are found to be lognormal in the size interval 0.4–2.0 μm with nearly identical shapes. Changes of the lognormal part of the volume distributions are found to be connected to the total dust mass in a systematic way. The total dust mass is correlated to the Ca 2+ concentration, and data do not show any enrichment in Ca 2+ from exposed continental shelves due to lower sea levels during the last glacial maximum. The total dust mass is strongly connected to δ 18 O. The volume distribution of the particles in the size interval 2.0–6.0 μm is found to be almost the same in most periods. The exceptions are the “cold” periods in the last part of the last glacial period, where the volume of these particles is higher than in most periods, and the periods from the Eemian and just above the Eemian where the volume of these particles is lower. The volume distributions of both the Eemian “warm” periods and the “cold” Eemian events are different from the distributions in ice from both below and above the Eemian ice. Climate changes appear to have modified the processes of production, transport, modification, and deposition of the dust aerosol in the same way over the last 120,000 years or more.",
    url = "https://doi.org/10.1029/97jc01490",
    doi = "10.1029/97jc01490",
    openalex = "W2118349946"
}

The continuous sulfate analysis of two Antarctic ice cores, one from the Antarctic Peninsula region and one from West Antarctica, provides an annually resolved proxy history of southern semisphere volcanism since early in the 15th century. The dating is accurate within ±3 years due to the high rate of snow accumulation at both core sites and the small sample sizes used for analysis. The two sulfate records are consistent with each other. A systematic and objective method of separating outstanding sulfate events from the background sulfate flux is proposed and used to identify all volcanic signals. The resulting volcanic chronology covering 1417–1989 A.D. resolves temporal ambiguities about several recently discovered events. A number of previously unknown, moderate eruptions during late 1600s are uncovered in this chronology. The eruption of Tambora (1815) and the recently discovered eruption of Kuwae (1453) in the tropical South Pacific injected the greatest amount of sulfur dioxide into the southern hemisphere stratosphere during the last half millennium. A technique for comparing the magnitude of volcanic events preserved within different ice cores is developed using normalized sulfate flux. For the same eruptions the variability of the volcanic sulfate flux between the cores is within ±20% of the sulfate flux from the Tambora eruption.

@article{doi10102997jd01394,
    author = "Cole‐Dai, Jihong and Mosley‐Thompson, Ellen and Thompson, Lonnie G.",
    title = "Annually resolved southern hemisphere volcanic history from two Antarctic ice cores",
    year = "1997",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "The continuous sulfate analysis of two Antarctic ice cores, one from the Antarctic Peninsula region and one from West Antarctica, provides an annually resolved proxy history of southern semisphere volcanism since early in the 15th century. The dating is accurate within ±3 years due to the high rate of snow accumulation at both core sites and the small sample sizes used for analysis. The two sulfate records are consistent with each other. A systematic and objective method of separating outstanding sulfate events from the background sulfate flux is proposed and used to identify all volcanic signals. The resulting volcanic chronology covering 1417–1989 A.D. resolves temporal ambiguities about several recently discovered events. A number of previously unknown, moderate eruptions during late 1600s are uncovered in this chronology. The eruption of Tambora (1815) and the recently discovered eruption of Kuwae (1453) in the tropical South Pacific injected the greatest amount of sulfur dioxide into the southern hemisphere stratosphere during the last half millennium. A technique for comparing the magnitude of volcanic events preserved within different ice cores is developed using normalized sulfate flux. For the same eruptions the variability of the volcanic sulfate flux between the cores is within ±20\% of the sulfate flux from the Tambora eruption.",
    url = "https://doi.org/10.1029/97jd01394",
    doi = "10.1029/97jd01394",
    openalex = "W1982605387",
    references = "doi101029jd090id07p12901"
}

Samples of sediments from beneath Ice Stream B (at camp UpB), West Antarctica, provide the first opportunity to study the relationship between sediment properties and physical conditions in a sub-ice-stream environment. Piston coring in holes bored by hot-water drilling yielded five 1-3 m long, undisturbed subglacial sediment cores. We analyzed granulometry, composition, and particle morphology in these cores. The UpB cores are composed of a clay-rich, unsorted diamicton containing rare marine diatoms. Sedimentary particles in these cores bear no evidence of the recent crushing or abrasion that is common in other subglacial sedimentary environments. The presence of reworked diatoms and their state of preservation, as well as the relative spatial homogeneity of this diamicton, suggest that the UpB cores sampled a several-meter-thick till layer and not in situ glacimarine sediments. The till does incorporate material recycled from the subjacent poorly indurated Tertiary glacimarine sediments of the Ross Sea sedimentary basin, which extends beneath this part of the West Antarctic Ice Sheet. We propose that the lack of significant comminution in the UpB till is ultimately due to its setting over these easily erodible, clay-rich source sediments. The resulting fine-grained till matrix inhibits glacial comminution, because it facilitates buildup of high pore-water pressures and hinders interparticle stress concentrations. Our observations are consistent with the conjecture that subglacial deformation of weak, fine-grained tills does not produce significant comminution of till debris (Elson 1988). Based on our findings, we hypothesize that extensive layers of weak till may develop preferentially where ice overrides preexisting, poorly indurated, fine-grained sediments. Since such weak till layers create a permissive condition for ice streaming, sub-glacial geology may have an indirect but strong control over the location, extent, and basal mechanics of ice streams.

@article{doi102110jsr68487,
    author = "Tulaczyk, Sławek and Kamb, Barclay and Scherer, R. P. and Engelhardt, Hermann",
    title = "Sedimentary processes at the base of a West Antarctic ice stream; constraints from textural and compositional properties of subglacial debris",
    year = "1998",
    journal = "Journal of Sedimentary Research",
    abstract = "Samples of sediments from beneath Ice Stream B (at camp UpB), West Antarctica, provide the first opportunity to study the relationship between sediment properties and physical conditions in a sub-ice-stream environment. Piston coring in holes bored by hot-water drilling yielded five 1-3 m long, undisturbed subglacial sediment cores. We analyzed granulometry, composition, and particle morphology in these cores. The UpB cores are composed of a clay-rich, unsorted diamicton containing rare marine diatoms. Sedimentary particles in these cores bear no evidence of the recent crushing or abrasion that is common in other subglacial sedimentary environments. The presence of reworked diatoms and their state of preservation, as well as the relative spatial homogeneity of this diamicton, suggest that the UpB cores sampled a several-meter-thick till layer and not in situ glacimarine sediments. The till does incorporate material recycled from the subjacent poorly indurated Tertiary glacimarine sediments of the Ross Sea sedimentary basin, which extends beneath this part of the West Antarctic Ice Sheet. We propose that the lack of significant comminution in the UpB till is ultimately due to its setting over these easily erodible, clay-rich source sediments. The resulting fine-grained till matrix inhibits glacial comminution, because it facilitates buildup of high pore-water pressures and hinders interparticle stress concentrations. Our observations are consistent with the conjecture that subglacial deformation of weak, fine-grained tills does not produce significant comminution of till debris (Elson 1988). Based on our findings, we hypothesize that extensive layers of weak till may develop preferentially where ice overrides preexisting, poorly indurated, fine-grained sediments. Since such weak till layers create a permissive condition for ice streaming, sub-glacial geology may have an indirect but strong control over the location, extent, and basal mechanics of ice streams.",
    url = "https://doi.org/10.2110/jsr.68.487",
    doi = "10.2110/jsr.68.487",
    openalex = "W2100545965",
    references = "doi101126science16138451011"
}

Extensive archives of volcanic history are available from ice cores recovered from the Antarctic and Greenland ice sheets that receive and preserve sulfuric acid fallout from explosive volcanic eruptions. The continuous, detailed (average 1.2 samples per year) sulfate measurements of a 200‐m ice core from a remote East Antarctica site (Plateau Remote) provide a record of Southern Hemisphere volcanism over the last 4100 years. This extends the volcanic record beyond the last 1000 years covered by previous Antarctic ice cores. An average of 1.3 eruptions per century is recorded in East Antarctic snow during the last 4100 years. The record shows that on average eruptions have been more frequent and more explosive during the most recent 2000 years than in the previous 2100 years. Intervals up to 500 years are observed in which few explosive volcanic signals are detected. These periods include 2000–1500 B.C. (no eruptions), 500–1 B.C. (two eruptions), and 700–1200 A.D. (two eruptions). This new Plateau Remote volcanic record is compared with those from previous Antarctic ice cores covering the last 1000 years. In terms of dates for volcanic events, the new record is in excellent agreement with the earlier records. However, significant discrepancies are found between these records in relative signal magnitude (volcanic flux) of several well‐known events. The discrepancies among the records may be explained by the differences in the glaciology at the ice core sites, analytical techniques used for sulfate and sulfuric acid measurement, and the selection of detection thresholds for volcanic signals. Comparison with Greenland ice core volcanic records indicates that during the last millennium, nine large, low‐latitude eruptions contributed significant amounts of volcanic aerosols to the atmosphere of both hemispheres, potentially affecting global climate. In contrast, only one or possibly two such eruptions are found in the first millennium A.D.

@article{doi1010292000jd900254,
    author = "Cole‐Dai, Jihong and Mosley‐Thompson, Ellen and Wight, Shawn P. and Thompson, Lonnie G.",
    title = "A 4100‐year record of explosive volcanism from an East Antarctica ice core",
    year = "2000",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "Extensive archives of volcanic history are available from ice cores recovered from the Antarctic and Greenland ice sheets that receive and preserve sulfuric acid fallout from explosive volcanic eruptions. The continuous, detailed (average 1.2 samples per year) sulfate measurements of a 200‐m ice core from a remote East Antarctica site (Plateau Remote) provide a record of Southern Hemisphere volcanism over the last 4100 years. This extends the volcanic record beyond the last 1000 years covered by previous Antarctic ice cores. An average of 1.3 eruptions per century is recorded in East Antarctic snow during the last 4100 years. The record shows that on average eruptions have been more frequent and more explosive during the most recent 2000 years than in the previous 2100 years. Intervals up to 500 years are observed in which few explosive volcanic signals are detected. These periods include 2000–1500 B.C. (no eruptions), 500–1 B.C. (two eruptions), and 700–1200 A.D. (two eruptions). This new Plateau Remote volcanic record is compared with those from previous Antarctic ice cores covering the last 1000 years. In terms of dates for volcanic events, the new record is in excellent agreement with the earlier records. However, significant discrepancies are found between these records in relative signal magnitude (volcanic flux) of several well‐known events. The discrepancies among the records may be explained by the differences in the glaciology at the ice core sites, analytical techniques used for sulfate and sulfuric acid measurement, and the selection of detection thresholds for volcanic signals. Comparison with Greenland ice core volcanic records indicates that during the last millennium, nine large, low‐latitude eruptions contributed significant amounts of volcanic aerosols to the atmosphere of both hemispheres, potentially affecting global climate. In contrast, only one or possibly two such eruptions are found in the first millennium A.D.",
    url = "https://doi.org/10.1029/2000jd900254",
    doi = "10.1029/2000jd900254",
    openalex = "W2073693306",
    references = "doi101029jd090id07p12901"
}

Geochemical data and geophysical measurements from a 554‐m ice‐core from Taylor Dome, East Antarctica, provide the basis for climate reconstruction in the western Ross Embayment through the entire Wisconsinan and Holocene. In comparison with ice cores from central East and West Antarctica, Taylor Dome shows greater variance of temperature, snow accumulation, and aerosol concentrations, reflecting significant variability in atmospheric circulation and air mass moisture content. Extreme aridity during the last glacial maximum at Taylor Dome reflects both colder temperatures and a shift in atmospheric circulation patterns associated with the advance of the Ross Sea ice sheet and accounts for regional alpine glacier retreats and high lake levels in the Dry Valleys. Inferred relationships between spatial accumulation gradients and ice sheet configuration indicate that advance of the Ross Sea ice sheet began in late marine isotope stage 5 or early stage 4. Precise dating of the Taylor Dome core achieved by trace‐gas correlation with central Greenland ice cores shows that abrupt deglacial warming at Taylor Dome was near‐synchronous with the ∼14.6 ka warming in central Greenland and lags the general warming trend in other Antarctic ice cores by at least 3000 years. Deglacial warming was following by a warm interval and transient cooling between 14.6 and 11.7 ka, synchronous with the Bølling/Allerød warming and Younger Dryas cooling events in central Greenland, and out of phase with the Antarctic Cold Reversal recorded in the Byrd (West Antarctica) ice core. Rapid climate changes during marine isotope stages 4 and 3 at Taylor Dome are similar in character to, and may be in phase with, the Northern Hemisphere stadial–interstadial (Dansgaard–Oeschger) events. Results from Taylor Dome illustrate the importance of obtaining ice cores from multiple Antarctic sites, to provide wide spatial coverage of past climate and ice dynamics.

@article{doi101111j04353676200000122x,
    author = "Steig, Eric J. and Morse, D. L. and Waddington, Edwin D. and Stuiver, Minze and Grootes, Pieter Meiert and Mayewski, Paul A. and Twickler, Mark S. and Whitlow, Sallie I.",
    title = "Wisconsinan and holocene climate history from an ice core at taylor dome, western ross embayment, antarctica",
    year = "2000",
    journal = "Geografiska Annaler Series A Physical Geography",
    abstract = "Geochemical data and geophysical measurements from a 554‐m ice‐core from Taylor Dome, East Antarctica, provide the basis for climate reconstruction in the western Ross Embayment through the entire Wisconsinan and Holocene. In comparison with ice cores from central East and West Antarctica, Taylor Dome shows greater variance of temperature, snow accumulation, and aerosol concentrations, reflecting significant variability in atmospheric circulation and air mass moisture content. Extreme aridity during the last glacial maximum at Taylor Dome reflects both colder temperatures and a shift in atmospheric circulation patterns associated with the advance of the Ross Sea ice sheet and accounts for regional alpine glacier retreats and high lake levels in the Dry Valleys. Inferred relationships between spatial accumulation gradients and ice sheet configuration indicate that advance of the Ross Sea ice sheet began in late marine isotope stage 5 or early stage 4. Precise dating of the Taylor Dome core achieved by trace‐gas correlation with central Greenland ice cores shows that abrupt deglacial warming at Taylor Dome was near‐synchronous with the ∼14.6 ka warming in central Greenland and lags the general warming trend in other Antarctic ice cores by at least 3000 years. Deglacial warming was following by a warm interval and transient cooling between 14.6 and 11.7 ka, synchronous with the Bølling/Allerød warming and Younger Dryas cooling events in central Greenland, and out of phase with the Antarctic Cold Reversal recorded in the Byrd (West Antarctica) ice core. Rapid climate changes during marine isotope stages 4 and 3 at Taylor Dome are similar in character to, and may be in phase with, the Northern Hemisphere stadial–interstadial (Dansgaard–Oeschger) events. Results from Taylor Dome illustrate the importance of obtaining ice cores from multiple Antarctic sites, to provide wide spatial coverage of past climate and ice dynamics.",
    url = "https://doi.org/10.1111/j.0435-3676.2000.00122.x",
    doi = "10.1111/j.0435-3676.2000.00122.x",
    openalex = "W2094502958",
    references = "doi101017s0022143000030288, doi101029rg026i001p00149, hammer1994electrical"
}

A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years. In general, Antarctic temperatures increased gradually while Greenland temperatures were decreasing or constant, and the termination of Antarctic warming was apparently coincident with the onset of rapid warming in Greenland. This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales.

@article{doi101126science2915501109,
    author = "Blunier, Thomas and Brook, Edward J.",
    title = "Timing of Millennial-Scale Climate Change in Antarctica and Greenland During the Last Glacial Period",
    year = "2001",
    journal = "Science",
    abstract = {A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years. In general, Antarctic temperatures increased gradually while Greenland temperatures were decreasing or constant, and the termination of Antarctic warming was apparently coincident with the onset of rapid warming in Greenland. This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales.},
    url = "https://doi.org/10.1126/science.291.5501.109",
    doi = "10.1126/science.291.5501.109",
    openalex = "W2099667979",
    references = "doi1010160277379187900035, doi101038235429a0, doi101038329403a0"
}

A record of atmospheric carbon dioxide (CO2) concentration during the transition from the Last Glacial Maximum to the Holocene, obtained from the Dome Concordia, Antarctica, ice core, reveals that an increase of 76 parts per million by volume occurred over a period of 6000 years in four clearly distinguishable intervals. The close correlation between CO2 concentration and Antarctic temperature indicates that the Southern Ocean played an important role in causing the CO2 increase. However, the similarity of changes in CO2 concentration and variations of atmospheric methane concentration suggests that processes in the tropics and in the Northern Hemisphere, where the main sources for methane are located, also had substantial effects on atmospheric CO2 concentrations.

@article{doi101126science2915501112,
    author = "Monnin, Eric and Indermühle, Andreas and Dällenbach, A. and Flückiger, Jacqueline and Stauffer, Bernhard and Stocker, Thomas F. and Raynaud, Dominique and Barnola, Jean-Marc",
    title = "Atmospheric CO 2 Concentrations over the Last Glacial Termination",
    year = "2001",
    journal = "Science",
    abstract = "A record of atmospheric carbon dioxide (CO2) concentration during the transition from the Last Glacial Maximum to the Holocene, obtained from the Dome Concordia, Antarctica, ice core, reveals that an increase of 76 parts per million by volume occurred over a period of 6000 years in four clearly distinguishable intervals. The close correlation between CO2 concentration and Antarctic temperature indicates that the Southern Ocean played an important role in causing the CO2 increase. However, the similarity of changes in CO2 concentration and variations of atmospheric methane concentration suggests that processes in the tropics and in the Northern Hemisphere, where the main sources for methane are located, also had substantial effects on atmospheric CO2 concentrations.",
    url = "https://doi.org/10.1126/science.291.5501.112",
    doi = "10.1126/science.291.5501.112",
    openalex = "W2035587516",
    references = "doi10103829447, doi101038331609a0"
}

Volcanic ash, or tephra layers, are found in the Taylor Dome, Siple Dome A, and Siple Dome B ice cores. Significant shard concentrations are found at a number of depths in all three cores. Electron and ion microprobe analyses indicate that the geochemical composition of most layers is basaltic, basanitic, or trachytic, and the geochemical signatures of the layers suggest derivation from the Pleiades volcanic center, Mt. Melbourne volcano, or small mafic centers, probably in the Royal Society Range area. Presence of tephra layers suggests an episode of previously unrecognized Antarctic volcanic activity between 1776 and 1805 A.D., from at least two volcanic centers. A strong geochemical correlation (D = 3.49 and 3.97 with a value of 4 considered identical) is observed between tephra layers at depth of 79.2 m in the Taylor Dome ice core, and layers between 97.2 and 97.7 m depth in the Siple B core. This correlation, and the highly accurate depth‐age scale of the Siple B core suggest that the age of this horizon in the Taylor Dome ice core presented by Steig et al. [1998a, 2000] should be revised downward, to the younger age of 675 ± 25 years before 1995. This revised chronology is consistent with vertical strain measurements presented by Hawley et al. [2003].

@article{doi1010292002jb002056,
    author = "Dunbar, Nelia and Zielinski, Gregory A. and Voisins, Daniel T.",
    title = "Tephra layers in the Siple Dome and Taylor Dome ice cores, Antarctica: Sources and correlations",
    year = "2003",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "Volcanic ash, or tephra layers, are found in the Taylor Dome, Siple Dome A, and Siple Dome B ice cores. Significant shard concentrations are found at a number of depths in all three cores. Electron and ion microprobe analyses indicate that the geochemical composition of most layers is basaltic, basanitic, or trachytic, and the geochemical signatures of the layers suggest derivation from the Pleiades volcanic center, Mt. Melbourne volcano, or small mafic centers, probably in the Royal Society Range area. Presence of tephra layers suggests an episode of previously unrecognized Antarctic volcanic activity between 1776 and 1805 A.D., from at least two volcanic centers. A strong geochemical correlation (D = 3.49 and 3.97 with a value of 4 considered identical) is observed between tephra layers at depth of 79.2 m in the Taylor Dome ice core, and layers between 97.2 and 97.7 m depth in the Siple B core. This correlation, and the highly accurate depth‐age scale of the Siple B core suggest that the age of this horizon in the Taylor Dome ice core presented by Steig et al. [1998a, 2000] should be revised downward, to the younger age of 675 ± 25 years before 1995. This revised chronology is consistent with vertical strain measurements presented by Hawley et al. [2003].",
    url = "https://doi.org/10.1029/2002jb002056",
    doi = "10.1029/2002jb002056",
    openalex = "W2036264079",
    references = "kyle1978compositions, kyle1981tephra"
}

Interpretation of the chemical layers measured in ice cores requires knowledge of processes occurring after their deposition on the ice sheet. We present evidence for the diffusion of soluble ions in the top 350 m of the Dome C ice core, Antarctica, that helps in explaining the unexpectedly broad volcanic peaks observed at depth. A windowed‐differencing operation applied to chemical time series indicates a damping of the signals over the past 11,000 years, independent of minor climatic variation, for sulfate and chloride, but not sodium. This implies a diffusive process is transporting both sulfate and chloride ions while the sodium ions remain fixed. We estimate the effective diffusivity in the core to be 4.7 × 10 −8 m 2 yr −1 for sulfate and 2.0 × 10 −7 m 2 yr −1 for chloride. These values are not high enough to significantly disrupt chemical interpretation in this section of core, but could be significant for older ice. The temperature of this section of ice (−53°C) implies that the predominantly acidic sulfate (and possibly chloride ions) will exist in the liquid phase while the sodium may be solid. We propose and develop two new mechanisms that could explain the observed solute movement. One involves the diffusion of solute through a connected vein network driven by liquid concentration imbalances instigated by the process of grain growth. The other considers a system of discontinuous veins where grain growth increases connectivity between isolated vein clusters allowing the spread of solute. In both mechanisms, the effective diffusivity is governed indirectly by grain growth rate; this may be a significant factor controlling effective diffusion in other cores.

@article{doi1010292002jd002538,
    author = "Barnes, Piers R. F. and Wolff, Eric and Mader, H. M. and Udisti, R. and Castellano, E. and Röthlisberger, Regine",
    title = "Evolution of chemical peak shapes in the Dome C, Antarctica, ice core",
    year = "2003",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "Interpretation of the chemical layers measured in ice cores requires knowledge of processes occurring after their deposition on the ice sheet. We present evidence for the diffusion of soluble ions in the top 350 m of the Dome C ice core, Antarctica, that helps in explaining the unexpectedly broad volcanic peaks observed at depth. A windowed‐differencing operation applied to chemical time series indicates a damping of the signals over the past 11,000 years, independent of minor climatic variation, for sulfate and chloride, but not sodium. This implies a diffusive process is transporting both sulfate and chloride ions while the sodium ions remain fixed. We estimate the effective diffusivity in the core to be 4.7 × 10 −8 m 2 yr −1 for sulfate and 2.0 × 10 −7 m 2 yr −1 for chloride. These values are not high enough to significantly disrupt chemical interpretation in this section of core, but could be significant for older ice. The temperature of this section of ice (−53°C) implies that the predominantly acidic sulfate (and possibly chloride ions) will exist in the liquid phase while the sodium may be solid. We propose and develop two new mechanisms that could explain the observed solute movement. One involves the diffusion of solute through a connected vein network driven by liquid concentration imbalances instigated by the process of grain growth. The other considers a system of discontinuous veins where grain growth increases connectivity between isolated vein clusters allowing the spread of solute. In both mechanisms, the effective diffusivity is governed indirectly by grain growth rate; this may be a significant factor controlling effective diffusion in other cores.",
    url = "https://doi.org/10.1029/2002jd002538",
    doi = "10.1029/2002jd002538",
    openalex = "W2095002819",
    references = "doi1010160012821x80901703"
}

The conventional interpretation of ice core deuterium and oxygen 18 isotope profiles based on the use of present‐day observations (spatial slope) underestimates glacial‐interglacial surface temperature changes in Central Greenland by up to a factor of two. This likely results from changes in the seasonality of the precipitation due to the particular location of the Greenland ice sheet next to the highly variable northern polar front. In this regard the situation is much simpler for central Antarctica and this should be reflected in the temperature interpretation of ice core isotopic records. With this in mind, we closely examine all relevant information, focusing on the East Antarctic Plateau where both model and empirical isotope‐temperature estimates are available. We point to the fact that correctly accounting for the influence of ocean isotopic change is important when interpreting deuterium profiles from ice cores in this region. The evidence presently available indicates that, unlike for Greenland, the present‐day spatial‐slope can probably be taken as a surrogate of the temporal slope to interpret glacial‐interglacial isotopic changes at sites such as Vostok and EPICA Dome C. Corresponding temperature changes are within −10% to +30% of those obtained from the conventional interpretation based on the use of the spatial slope.

@article{doi1010292002jd002677,
    author = "Jouzel, J. and Vimeux, Françoise and Caillon, Nicolas and Delaygue, Gilles and Hoffmann, Georg F. and Masson‐Delmotte, Valérie and Parrenin, Frédéric",
    title = "Magnitude of isotope/temperature scaling for interpretation of central Antarctic ice cores",
    year = "2003",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "The conventional interpretation of ice core deuterium and oxygen 18 isotope profiles based on the use of present‐day observations (spatial slope) underestimates glacial‐interglacial surface temperature changes in Central Greenland by up to a factor of two. This likely results from changes in the seasonality of the precipitation due to the particular location of the Greenland ice sheet next to the highly variable northern polar front. In this regard the situation is much simpler for central Antarctica and this should be reflected in the temperature interpretation of ice core isotopic records. With this in mind, we closely examine all relevant information, focusing on the East Antarctic Plateau where both model and empirical isotope‐temperature estimates are available. We point to the fact that correctly accounting for the influence of ocean isotopic change is important when interpreting deuterium profiles from ice cores in this region. The evidence presently available indicates that, unlike for Greenland, the present‐day spatial‐slope can probably be taken as a surrogate of the temporal slope to interpret glacial‐interglacial isotopic changes at sites such as Vostok and EPICA Dome C. Corresponding temperature changes are within −10\% to +30\% of those obtained from the conventional interpretation based on the use of the spatial slope.",
    url = "https://doi.org/10.1029/2002jd002677",
    doi = "10.1029/2002jd002677",
    openalex = "W2124143154"
}

A 49.9-m firn-ice core recovered from the King George Island ice cap (690 m above sea level) in the summer of 1995-96 was analyzed for stable isotope composition and major anionic species.Borehole temperature was measured down to a depth of 45 m, indicating an ice cap near the pressure melting point; density measurements show a firn-ice transition at a depth of 35 m.The environmental record is homogenized due to intense superficial melting, followed by percolation and refreezing.The upper 2.7 m is considered representative of the original precipitation and provides reference for the background chemical composition in the South Shetlands (δD: -72.2 • / ••, δ 18 O: -9.7 • / ••, Cl -: 120 µEq L -1, SO -2 4: 28 µEq L -1, excess-SO -2 4: 15 µEq L -1).Stable isotope seasonal variations are recognized down to 15 m, allowing dating of the core.A simple Nye's model was used to date the core below this depth, resulting in a mean net accumulation rate of 0.59 m a -1 (water equivalent) over 73 years of precipitation.Below 37 m, the environmental record was intensively washed-out by the presence of a water table.

@article{doi1031789pabv4n1002,
    author = "Simões, Jefferson Cárdia and Ferron, Francisco Adolfo and Bernardo, Ronaldo and Aristarain, Alberto J. and Stiévenard, M. and Pourchet, M. and Delmas, Robert J.",
    title = "Ice core study from the King George Island, South Shetlands, Antarctica",
    year = "2004",
    journal = "PESQUISA ANTÁRTICA BRASILEIRA (Academia Brasileira de Ciências)",
    abstract = "A 49.9-m firn-ice core recovered from the King George Island ice cap (690 m above sea level) in the summer of 1995-96 was analyzed for stable isotope composition and major anionic species.Borehole temperature was measured down to a depth of 45 m, indicating an ice cap near the pressure melting point; density measurements show a firn-ice transition at a depth of 35 m.The environmental record is homogenized due to intense superficial melting, followed by percolation and refreezing.The upper 2.7 m is considered representative of the original precipitation and provides reference for the background chemical composition in the South Shetlands (δD: -72.2 • / ••, δ 18 O: -9.7 • / ••, Cl -: 120 µEq L -1, SO -2 4: 28 µEq L -1, excess-SO -2 4: 15 µEq L -1).Stable isotope seasonal variations are recognized down to 15 m, allowing dating of the core.A simple Nye's model was used to date the core below this depth, resulting in a mean net accumulation rate of 0.59 m a -1 (water equivalent) over 73 years of precipitation.Below 37 m, the environmental record was intensively washed-out by the presence of a water table.",
    url = "https://doi.org/10.31789/pab.v4n1.002",
    doi = "10.31789/pab.v4n1.002",
    openalex = "W4387925242",
    references = "doi103189s0022143000028367"
}

Air mass trajectories in the Southern Hemisphere provide a mechanism for transport to and deposition of volcanic products on the Antarctic ice sheet from local volcanoes and from tropical and subtropical volcanic centers. This study extends the detailed record of Antarctic, South American, and equatorial volcanism over the last 12,000 years using continuous glaciochemical series developed from the Siple Dome A (SDMA) ice core, West Antarctica. The largest volcanic sulfate spike (280 μg/L) occurs at 5881 B.C.E. Other large signals with unknown sources are observed around 325 B.C.E. (270 μg/L) and 2818 B.C.E. (191 μg/L). Ages of several large equatorial or Southern Hemisphere volcanic eruptions are synchronous with many sulfate peaks detected in the SDMA volcanic ice chemistry record. The microprobe “fingerprinting” of glass shards in the SDMA core points to the following Antarctic volcanic centers as sources of tephra found in the SDMA core: Balenny Island, Pleiades, Mount Berlin, Mount Takahe, and Mount Melbourne as well as Mount Hudson and possibly Mount Burney volcanoes of South America. Identified volcanic sources provide an insight into the poorly resolved transport history of volcanic products from source volcanoes to the West Antarctic ice sheet.

@article{doi1010292005jd006072,
    author = "Kurbatov, Andrei V. and Zielinski, Gregory A. and Dunbar, Nelia and Mayewski, Paul A. and Meyerson, E. A. and Sneed, Sharon B. and Taylor, K. C.",
    title = "A 12,000 year record of explosive volcanism in the Siple Dome Ice Core, West Antarctica",
    year = "2006",
    journal = "Journal of Geophysical Research Atmospheres",
    abstract = "Air mass trajectories in the Southern Hemisphere provide a mechanism for transport to and deposition of volcanic products on the Antarctic ice sheet from local volcanoes and from tropical and subtropical volcanic centers. This study extends the detailed record of Antarctic, South American, and equatorial volcanism over the last 12,000 years using continuous glaciochemical series developed from the Siple Dome A (SDMA) ice core, West Antarctica. The largest volcanic sulfate spike (280 μg/L) occurs at 5881 B.C.E. Other large signals with unknown sources are observed around 325 B.C.E. (270 μg/L) and 2818 B.C.E. (191 μg/L). Ages of several large equatorial or Southern Hemisphere volcanic eruptions are synchronous with many sulfate peaks detected in the SDMA volcanic ice chemistry record. The microprobe “fingerprinting” of glass shards in the SDMA core points to the following Antarctic volcanic centers as sources of tephra found in the SDMA core: Balenny Island, Pleiades, Mount Berlin, Mount Takahe, and Mount Melbourne as well as Mount Hudson and possibly Mount Burney volcanoes of South America. Identified volcanic sources provide an insight into the poorly resolved transport history of volcanic products from source volcanoes to the West Antarctic ice sheet.",
    url = "https://doi.org/10.1029/2005jd006072",
    doi = "10.1029/2005jd006072",
    openalex = "W2147027563",
    references = "doi1010292000gl011499, kyle1981tephra"
}

@misc{crossref2007antarctica,
    title = "Antarctica",
    year = "2007",
    booktitle = "Encyclopedia of Environment and Society",
    url = "https://doi.org/10.4135/9781412953924.n29",
    doi = "10.4135/9781412953924.n29"
}

The seasonality of moisture sources for precipitation in Antarctica is studied with a Lagrangian moisture source diagnostic. Moisture origin for precipitation in Antarctica has strongly asymmetric properties, which are related to the Antarctic topography, seasonal sea ice coverage, and the land/ocean contrasts in the mid‐latitudes of the southern hemisphere. The highest altitudes of the East Antarctic ice shield, where major ice cores have been drilled, have mean source latitudes of 45–40°S year‐round. This finding contrasts to results from previous Lagrangian studies which detected a more southerly moisture origin due to too short trajectories. Now, results from Lagrangian moisture source diagnostics are consistent with findings from general circulation models with tagged tracers. Thus, both approaches can serve as a common benchmark for the interpretation of moisture source indicators based on stable isotopes, such as deuterium excess, in Antarctic ice cores.

@article{doi1010292009gl040242,
    author = "Sodemann, Harald and Stohl, A.",
    title = "Asymmetries in the moisture origin of Antarctic precipitation",
    year = "2009",
    journal = "Geophysical Research Letters",
    abstract = "The seasonality of moisture sources for precipitation in Antarctica is studied with a Lagrangian moisture source diagnostic. Moisture origin for precipitation in Antarctica has strongly asymmetric properties, which are related to the Antarctic topography, seasonal sea ice coverage, and the land/ocean contrasts in the mid‐latitudes of the southern hemisphere. The highest altitudes of the East Antarctic ice shield, where major ice cores have been drilled, have mean source latitudes of 45–40°S year‐round. This finding contrasts to results from previous Lagrangian studies which detected a more southerly moisture origin due to too short trajectories. Now, results from Lagrangian moisture source diagnostics are consistent with findings from general circulation models with tagged tracers. Thus, both approaches can serve as a common benchmark for the interpretation of moisture source indicators based on stable isotopes, such as deuterium excess, in Antarctic ice cores.",
    url = "https://doi.org/10.1029/2009gl040242",
    doi = "10.1029/2009gl040242",
    openalex = "W2068521033",
    references = "doi1010292002jd002677, doi1010292005jd006888, doi1010292006gl026936, doi1010292007jd008503, doi101029rg026i001p00149, doi101126science1059702, doi1011751520049320031310272saitsa20co2, doi1011751525754120040050656alaota20co2, doi1011752007jcli21391, doi105194acp524612005"
}

Abstract In contrast to earlier studies, the authors describe the climatological deep low pressure system that exists over the South Pacific sector of the Southern Ocean, referred to as the Amundsen–Bellingshausen Seas low (ABSL), in terms of its relative (rather than actual) central pressure by removing the background area-averaged mean sea level pressure (MSLP). Doing so removes much of the influence of large-scale variability across the ABSL sector region (e.g., due to the southern annular mode), allowing a clearer understanding of ABSL variability and its effect on the regional climate of West Antarctica. Using ECMWF Interim Re-Analysis (ERA-Interim) fields, the annual cycle of the relative central pressure of the ABSL for the period from 1979 to 2011 shows a minimum (maximum) during winter (summer), differing considerably from the earlier studies based on actual central pressure, which suggests a semiannual oscillation. The annual cycle of the longitudinal position of the ABSL is insensitive to the background pressure, and shows it shifting westward from ∼250° to ∼220°E between summer and winter, in agreement with earlier studies. The authors demonstrate that ABSL variability, and in particular its longitudinal position, play an important role in controlling the surface climate of West Antarctica and the surrounding ocean by quantifying its influence on key meteorological parameters. Examination of the ABSL annual cycle in 17 CMIP5 climate models run with historical forcing shows that the majority of them have definite biases, especially in terms of longitudinal position, and a correspondingly poor representation of West Antarctic climate.

@article{doi101175jclid12008131,
    author = "Hosking, J. Scott and Orr, Andrew and Marshall, Gareth J. and Turner, John and Phillips, Tony",
    title = "The Influence of the Amundsen–Bellingshausen Seas Low on the Climate of West Antarctica and Its Representation in Coupled Climate Model Simulations",
    year = "2013",
    journal = "Journal of Climate",
    abstract = "Abstract In contrast to earlier studies, the authors describe the climatological deep low pressure system that exists over the South Pacific sector of the Southern Ocean, referred to as the Amundsen–Bellingshausen Seas low (ABSL), in terms of its relative (rather than actual) central pressure by removing the background area-averaged mean sea level pressure (MSLP). Doing so removes much of the influence of large-scale variability across the ABSL sector region (e.g., due to the southern annular mode), allowing a clearer understanding of ABSL variability and its effect on the regional climate of West Antarctica. Using ECMWF Interim Re-Analysis (ERA-Interim) fields, the annual cycle of the relative central pressure of the ABSL for the period from 1979 to 2011 shows a minimum (maximum) during winter (summer), differing considerably from the earlier studies based on actual central pressure, which suggests a semiannual oscillation. The annual cycle of the longitudinal position of the ABSL is insensitive to the background pressure, and shows it shifting westward from ∼250° to ∼220°E between summer and winter, in agreement with earlier studies. The authors demonstrate that ABSL variability, and in particular its longitudinal position, play an important role in controlling the surface climate of West Antarctica and the surrounding ocean by quantifying its influence on key meteorological parameters. Examination of the ABSL annual cycle in 17 CMIP5 climate models run with historical forcing shows that the majority of them have definite biases, especially in terms of longitudinal position, and a correspondingly poor representation of West Antarctic climate.",
    url = "https://doi.org/10.1175/jcli-d-12-00813.1",
    doi = "10.1175/jcli-d-12-00813.1",
    openalex = "W2165964246",
    references = "doi101002qj828, doi1010292002jd002670, doi1010292007jc004269, doi1010292009gl037524, doi101038nature07669, doi101038ngeo1627, doi1011751520044220000131000amitec20co2, doi1011751520044220030164134titsam20co2, doi1011751520047719970782771tdoeno20co2, doi101175bamsd11000941"
}

Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last Interglacial–Glacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) project, protocols have been proposed to ensure consistent and robust correlation between different records of past climate. A key element of these protocols has been the formal definition and ordinal numbering of the sequence of Greenland Stadials (GS) and Greenland Interstadials (GI) within the most recent glacial period. The GS and GI periods are the Greenland expressions of the characteristic Dansgaard–Oeschger events that represent cold and warm phases of the North Atlantic region, respectively. We present here a more detailed and extended GS/GI template for the whole of the Last Glacial period. It is based on a synchronization of the NGRIP, GRIP, and GISP2 ice-core records that allows the parallel analysis of all three records on a common time scale. The boundaries of the GS and GI periods are defined based on a combination of stable-oxygen isotope ratios of the ice (δ18O, reflecting mainly local temperature) and calcium ion concentrations (reflecting mainly atmospheric dust loading) measured in the ice. The data not only resolve the well-known sequence of Dansgaard–Oeschger events that were first defined and numbered in the ice-core records more than two decades ago, but also better resolve a number of short-lived climatic oscillations, some defined here for the first time. Using this revised scheme, we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the Last Glacial period that are represented in the Greenland ice records. The final product constitutes an extended and better resolved Greenland stratotype sequence, against which other proxy records can be compared and correlated. It also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations.

@article{doi101016jquascirev201409007,
    author = "Rasmussen, Sune Olander and Bigler, Matthias and Blockley, Simon and Blunier, Thomas and Buchardt, S. L. and Clausen, Henrik and Cvijanović, Ivana and Dahl‐Jensen, Dorthe and Johnsen, S. J. and Fischer, Hubertus and Gkinis, Vasileios and Guillevic, Myriam and Hoek, Wim Z. and Lowe, J. John and Pedro, Joel B and Popp, Trevor and Seierstad, Inger K and Steffensen, J. P. and Svensson, Anders and Vallelonga, Paul and Vinther, Bo and Walker, Mike and Wheatley, J. J. and Winstrup, Mai",
    title = "A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy",
    year = "2014",
    journal = "Quaternary Science Reviews",
    abstract = "Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last Interglacial–Glacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) project, protocols have been proposed to ensure consistent and robust correlation between different records of past climate. A key element of these protocols has been the formal definition and ordinal numbering of the sequence of Greenland Stadials (GS) and Greenland Interstadials (GI) within the most recent glacial period. The GS and GI periods are the Greenland expressions of the characteristic Dansgaard–Oeschger events that represent cold and warm phases of the North Atlantic region, respectively. We present here a more detailed and extended GS/GI template for the whole of the Last Glacial period. It is based on a synchronization of the NGRIP, GRIP, and GISP2 ice-core records that allows the parallel analysis of all three records on a common time scale. The boundaries of the GS and GI periods are defined based on a combination of stable-oxygen isotope ratios of the ice (δ18O, reflecting mainly local temperature) and calcium ion concentrations (reflecting mainly atmospheric dust loading) measured in the ice. The data not only resolve the well-known sequence of Dansgaard–Oeschger events that were first defined and numbered in the ice-core records more than two decades ago, but also better resolve a number of short-lived climatic oscillations, some defined here for the first time. Using this revised scheme, we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the Last Glacial period that are represented in the Greenland ice records. The final product constitutes an extended and better resolved Greenland stratotype sequence, against which other proxy records can be compared and correlated. It also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations.",
    url = "https://doi.org/10.1016/j.quascirev.2014.09.007",
    doi = "10.1016/j.quascirev.2014.09.007",
    openalex = "W2007331923",
    references = "doi101002jqs1227, doi101002jqs2565, doi101002sici1099141719980708134283aidjqs38630co2a, doi1010160033589488900579, doi101016jquascirev200608002, doi1010292003rg000128, doi1010292005jd006079, doi10102996jc03365, doi10102997jc00880, doi10103829447, doi101038359311a0, doi101038360245a0, doi101038362527a0, doi101038364218a0, doi101038nature01690, doi101038nature02805, doi101038nature05301, doi101038nature08686, doi101038nature11789, doi101126science1157707, doi101126science2915501109, doi105194cp4472008"
}

Abstract The Amundsen Sea low (ASL) is a climatological low pressure center that exerts considerable influence on the climate of West Antarctica. Its potential to explain important recent changes in Antarctic climate, for example, in temperature and sea ice extent, means that it has become the focus of an increasing number of studies. Here, the authors summarize the current understanding of the ASL, using reanalysis datasets to analyze recent variability and trends, as well as ice-core chemistry and climate model projections, to examine past and future changes in the ASL, respectively. The ASL has deepened in recent decades, affecting the climate through its influence on the regional meridional wind field, which controls the advection of moisture and heat into the continent. Deepening of the ASL in spring is consistent with observed West Antarctic warming and greater sea ice extent in the Ross Sea. Climate model simulations for recent decades indicate that this deepening is mediated by tropical variability while climate model projections through the twenty-first century suggest that the ASL will deepen in some seasons in response to greenhouse gas concentration increases.

@article{doi101175bamsd14000181,
    author = "Raphael, Marilyn and Marshall, Gareth J. and Turner, John and Fogt, Ryan L. and Schneider, David P. and Dixon, Daniel A. and Hosking, J. Scott and Jones, Julie and Hobbs, Will",
    title = "The Amundsen Sea Low: Variability, Change, and Impact on Antarctic Climate",
    year = "2015",
    journal = "Bulletin of the American Meteorological Society",
    abstract = "Abstract The Amundsen Sea low (ASL) is a climatological low pressure center that exerts considerable influence on the climate of West Antarctica. Its potential to explain important recent changes in Antarctic climate, for example, in temperature and sea ice extent, means that it has become the focus of an increasing number of studies. Here, the authors summarize the current understanding of the ASL, using reanalysis datasets to analyze recent variability and trends, as well as ice-core chemistry and climate model projections, to examine past and future changes in the ASL, respectively. The ASL has deepened in recent decades, affecting the climate through its influence on the regional meridional wind field, which controls the advection of moisture and heat into the continent. Deepening of the ASL in spring is consistent with observed West Antarctic warming and greater sea ice extent in the Ross Sea. Climate model simulations for recent decades indicate that this deepening is mediated by tropical variability while climate model projections through the twenty-first century suggest that the ASL will deepen in some seasons in response to greenhouse gas concentration increases.",
    url = "https://doi.org/10.1175/bams-d-14-00018.1",
    doi = "10.1175/bams-d-14-00018.1",
    openalex = "W2057615471",
    references = "doi101175jclid12008131"
}

Abstract. The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ∼68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8–31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age–ice age difference (Δage) using a combination of firn densification modeling, ice-flow modeling, and a data set of δ15N-N2, a proxy for past firn column thickness. The largest Δage at WD occurs during the Last Glacial Maximum, and is 525 ± 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard–Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Δage at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the "bipolar seesaw".

@article{doi105194cp111532015,
    author = "Buizert, Christo and Cuffey, Kurt M. and Severinghaus, Jeffrey P. and Baggenstos, Daniel and Fudge, T. J. and Steig, Eric J. and Markle, Bradley and Winstrup, Mai and Rhodes, Rachael H. and Brook, Edward J. and Sowers, Todd and Clow, Gary D. and Cheng, Hai and Edwards, R. Lawrence and Sigl, Michael and McConnell, Joseph R. and Taylor, K. C.",
    title = "The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference",
    year = "2015",
    journal = "Climate of the past",
    abstract = {Abstract. The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ∼68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8–31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age–ice age difference (Δage) using a combination of firn densification modeling, ice-flow modeling, and a data set of δ15N-N2, a proxy for past firn column thickness. The largest Δage at WD occurs during the Last Glacial Maximum, and is 525 ± 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard–Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Δage at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the "bipolar seesaw".},
    url = "https://doi.org/10.5194/cp-11-153-2015",
    doi = "10.5194/cp-11-153-2015",
    openalex = "W2114095858",
    references = "doi101002jqs622, doi101016jquascirev201409007, doi1010292005jd006079, doi101038nature02494, doi101038nature02805, doi101038nature05301, doi101126science1064618, doi101126science2915501109, doi102458azujsrc5516947, doi103189s0022143000031208, openalexw2070611029"
}

Abstract. Ice cores provide temporal records of snow accumulation, a crucial component of Antarctic mass balance. Coastal areas are particularly under-represented in such records, despite their relatively high and sensitive accumulation rates. Here we present records from a 120 m ice core drilled on Derwael Ice Rise, coastal Dronning Maud Land (DML), East Antarctica in 2012. We date the ice core bottom back to 1745 ± 2 AD. δ18O and δD stratigraphy is supplemented by discontinuous major ion profiles, and verified independently by electrical conductivity measurements (ECM) to detect volcanic horizons. The resulting annual layer history is combined with the core density profile to calculate accumulation history, corrected for the influence of ice deformation. The mean long-term accumulation is 0.425 ± 0.035 m water equivalent (w.e.) a−1 (average corrected value). Reconstructed annual accumulation rates show an increase from 1955 onward to a mean value of 0.61 ± 0.02 m w.e. a−1 between 1955 and 2012. This trend is compared to other reported accumulation data in Antarctica, generally showing a high spatial variability. Output of the fully coupled Community Earth System Model demonstrates that sea ice and atmospheric patterns largely explain the accumulation variability. This is the first and longest record from a coastal ice core in East Antarctica showing a steady increase during the 20th and 21st centuries, thereby supporting modelling predictions.

@article{doi105194tc201627,
    author = "Philippe, Morgane and Tison, Jean‐Louis and Fjøsne, Karen and Hubbard, Bryn and Kjær, Helle Astrid and Lenaerts, Jan T. M. and Sheldon, Simon G. and Bondt, Kevin De and Claeys, Philippe and Pattyn, Frank",
    title = "Ice core evidence for a recent increase in snow accumulation in coastal Dronning Maud Land, East Antarctica",
    year = "2016",
    abstract = "Abstract. Ice cores provide temporal records of snow accumulation, a crucial component of Antarctic mass balance. Coastal areas are particularly under-represented in such records, despite their relatively high and sensitive accumulation rates. Here we present records from a 120 m ice core drilled on Derwael Ice Rise, coastal Dronning Maud Land (DML), East Antarctica in 2012. We date the ice core bottom back to 1745 ± 2 AD. δ18O and δD stratigraphy is supplemented by discontinuous major ion profiles, and verified independently by electrical conductivity measurements (ECM) to detect volcanic horizons. The resulting annual layer history is combined with the core density profile to calculate accumulation history, corrected for the influence of ice deformation. The mean long-term accumulation is 0.425 ± 0.035 m water equivalent (w.e.) a−1 (average corrected value). Reconstructed annual accumulation rates show an increase from 1955 onward to a mean value of 0.61 ± 0.02 m w.e. a−1 between 1955 and 2012. This trend is compared to other reported accumulation data in Antarctica, generally showing a high spatial variability. Output of the fully coupled Community Earth System Model demonstrates that sea ice and atmospheric patterns largely explain the accumulation variability. This is the first and longest record from a coastal ice core in East Antarctica showing a steady increase during the 20th and 21st centuries, thereby supporting modelling predictions.",
    url = "https://doi.org/10.5194/tc-2016-27",
    doi = "10.5194/tc-2016-27",
    openalex = "W2291947052",
    references = "doi103189172756505781829232, doi103189s0022143000028367"
}

Constraining how much and how fast the West Antarctic Ice Sheet (WAIS) will change in the coming decades has recently been identified as the highest priority in Antarctic research (National Academies, 2015). Here we review recent research on WAIS and outline further scientific objectives for the area now identified as the most likely to undergo near-term significant change: Thwaites Glacier and the adjacent Amundsen Sea. Multiple lines of evidence point to an ongoing rapid loss of ice in this region in response to changing atmospheric and oceanic conditions. Models of the ice sheet's dynamic behavior indicate a potential for greatly accelerated ice loss as ocean-driven melting at the Thwaites Glacier grounding zone and nearby areas leads to thinning, faster flow, and retreat. A complete retreat of the Thwaites Glacier basin would raise global sea level by more than three meters by entraining ice from adjacent catchments. This scenario could occur over the next few centuries, and faster ice loss could occur through processes omitted from most ice flow models such as hydrofracture and ice cliff failure, which have been observed in recent rapid ice retreats elsewhere. Increased basal melt at the grounding zone and increased potential for hydrofracture due to enhanced surface melt could initiate a more rapid collapse of Thwaites Glacier within the next few decades.

@article{doi101016jgloplacha201704008,
    author = "Scambos, T. A. and Bell, Robin E. and Alley, Richard B. and Anandakrishnan, S. and Bromwich, David H. and Brunt, Kelly M. and Christianson, Knut and Creyts, T. T. and Das, Sarah B. and DeConto, Robert M. and Dutrieux, Pierre and Fricker, H. A. and Holland, David M. and MacGregor, Joseph A. and Medley, Brooke and Nicolas, Julien P. and Pollard, David and Siegfried, Matthew R. and Smith, Andrew M. and Steig, Eric J. and Trusel, Luke D. and Vaughan, David G. and Yager, Patricia L.",
    title = "How much, how fast?: A science review and outlook for research on the instability of Antarctica's Thwaites Glacier in the 21st century",
    year = "2017",
    journal = "Global and Planetary Change",
    abstract = "Constraining how much and how fast the West Antarctic Ice Sheet (WAIS) will change in the coming decades has recently been identified as the highest priority in Antarctic research (National Academies, 2015). Here we review recent research on WAIS and outline further scientific objectives for the area now identified as the most likely to undergo near-term significant change: Thwaites Glacier and the adjacent Amundsen Sea. Multiple lines of evidence point to an ongoing rapid loss of ice in this region in response to changing atmospheric and oceanic conditions. Models of the ice sheet's dynamic behavior indicate a potential for greatly accelerated ice loss as ocean-driven melting at the Thwaites Glacier grounding zone and nearby areas leads to thinning, faster flow, and retreat. A complete retreat of the Thwaites Glacier basin would raise global sea level by more than three meters by entraining ice from adjacent catchments. This scenario could occur over the next few centuries, and faster ice loss could occur through processes omitted from most ice flow models such as hydrofracture and ice cliff failure, which have been observed in recent rapid ice retreats elsewhere. Increased basal melt at the grounding zone and increased potential for hydrofracture due to enhanced surface melt could initiate a more rapid collapse of Thwaites Glacier within the next few decades.",
    url = "https://doi.org/10.1016/j.gloplacha.2017.04.008",
    doi = "10.1016/j.gloplacha.2017.04.008",
    openalex = "W2606433261",
    references = "doi1010292006jf000664, doi101038264152a0, doi101038271321a0, doi101038342637a0, doi101038nature07809, doi101038nature08471, doi101038nature10968, doi101038nature17145, doi101126science1208336, doi101126science1228102, doi105194tc73752013"
}

Major explosive volcanic eruptions may significantly alter the global atmosphere for about 2–3 years. During that period, volcanic products (mainly H2SO4) with high residence time, stored in the stratosphere or, for shorter times, in the troposphere are gradually deposited onto polar ice caps. Antarctic snow may thus record acidic signals providing a history of past volcanic events. The high resolution sulphate concentration profile along a 197 m long ice core drilled at GV7 (Northern Victoria land) was obtained by Ion Chromatography on around 3500 discrete samples. The relatively high accumulation rate (241 ± 13 mm we yr −1) and the 5-cm sampling resolution allowed a preliminary counted age scale. The obtained stratigraphy covers roughly the last millennium and 24 major volcanic eruptions were identified, dated, and tentatively ascribed to a source volcano. The deposition flux of volcanic sulphate was calculated for each signature and the results were compared with data from other Antarctic ice cores at regional and continental scale. Our results show that the regional variability is of the same order of magnitude as the continental one.

@article{doi103390geosciences10010038,
    author = "Nardin, Raffaello and Amore, Alessandra and Becagli, Silvia and Caiazzo, Laura and Frezzotti, Massimo and Severi, Mirko and Stenni, Barbara and Traversi, Rita",
    title = "Volcanic Fluxes Over the Last Millennium as Recorded in the Gv7 Ice Core (Northern Victoria Land, Antarctica)",
    year = "2020",
    journal = "Geosciences",
    abstract = "Major explosive volcanic eruptions may significantly alter the global atmosphere for about 2–3 years. During that period, volcanic products (mainly H2SO4) with high residence time, stored in the stratosphere or, for shorter times, in the troposphere are gradually deposited onto polar ice caps. Antarctic snow may thus record acidic signals providing a history of past volcanic events. The high resolution sulphate concentration profile along a 197 m long ice core drilled at GV7 (Northern Victoria land) was obtained by Ion Chromatography on around 3500 discrete samples. The relatively high accumulation rate (241 ± 13 mm we yr −1) and the 5-cm sampling resolution allowed a preliminary counted age scale. The obtained stratigraphy covers roughly the last millennium and 24 major volcanic eruptions were identified, dated, and tentatively ascribed to a source volcano. The deposition flux of volcanic sulphate was calculated for each signature and the results were compared with data from other Antarctic ice cores at regional and continental scale. Our results show that the regional variability is of the same order of magnitude as the continental one.",
    url = "https://doi.org/10.3390/geosciences10010038",
    doi = "10.3390/geosciences10010038",
    openalex = "W3000505241",
    references = "doi101029jd090id07p12901"
}

Abstract. Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between −7.8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between −6.1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28 mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica.

@article{doi105194tc1430332020,
    author = "Seroussi, Hélène and Nowicki, Sophie and Payne, A. J. and Goelzer, Heiko and Lipscomb, William H. and Abe‐Ouchi, Ayako and Agosta, Cécile and Albrecht, Torsten and Asay‐Davis, Xylar and Barthel, Alice and Calov, Reinhard and Cullather, Richard and Dumas, Christophe and Galton‐Fenzi, Benjamin K. and Gladstone, Rupert and Golledge, Nicholas R. and Gregory, Jonathan M. and Greve, Ralf and Hattermann, Tore and Hoffman, Matthew J. and Humbert, Angelika and Huybrechts, Philippe and Jourdain, Nicolas C. and Kleiner, Thomas and Larour, Eric and Leguy, Gunter and Lowry, Daniel P. and Little, Chistopher M. and Morlighem, Mathieu and Pattyn, Frank and Pelle, Tyler and Price, Stephen and Quiquet, Aurélien and Reese, Ronja and Schlegel, Nicole‐Jeanne and Shepherd, Andrew and Simon, Erika and Smith, Robin S. and Straneo, Fiammetta and Sun, Sainan and Trusel, Luke D. and Breedam, Jonas Van and van de Wal, Roderik S. W. and Winkelmann, Ricarda and Zhao, Chen and Zhang, Tong and Zwinger, Thomas",
    title = "ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century",
    year = "2020",
    journal = "˜The œcryosphere",
    abstract = "Abstract. Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between −7.8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between −6.1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28 mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica.",
    url = "https://doi.org/10.5194/tc-14-3033-2020",
    doi = "10.5194/tc-14-3033-2020",
    openalex = "W3002630673",
    references = "doi1010022013jc009067, doi101002qj828, doi1010292006jf000664, doi1010292011gl046583, doi101029jb094ib04p04071, doi10103820859, doi101038nature17145, doi101038s415860180179y, doi101038s4158601908899, doi101073pnas1812883116, doi101126science1235798, doi105194tc73752013"
}

The insoluble particulate matter deposited on ice sheets provide key information to reconstruct past climate. The low concentration of some insoluble particulate matter, such as terrigenous particles and microfossils, challenges the efficiency of the recovery and the representativeness of the results. Here we present a new optimized method to extract, quantify and classify targeted low concentration insoluble particulate matter. Particle recovery rates and particle distribution were investigated using polystyrene particle standards filtered through Polycarbonate membrane filters and subsequently scanned in a scanning electron microscope. Experimental results in continuous and discrete sampling systems reveal consistent trends in the transport and removal of particulate material inside a filtration system. Statistical simulations are used to optimize the sample analyses required to achieve representative results. The analysis of diatoms in ice cores using this new method uncovered their potential to hold valuable climate records from the Antarctic Peninsula region. The data presented here evidence the presence of a measurable amount of marine diatoms with sub-annual variations, highlighting the potential of this record as a seasonal indicator. The new method presented provides an optimized and statistically representative approach for extracting, recovering and analyzing micrometre-sized, low-concentration insoluble particulate matter in ice.

@article{doi103389feart2021617043,
    author = "Tetzner, Dieter and Thomas, Elizabeth R. and Allen, Claire S. and Wolff, Eric",
    title = "A Refined Method to Analyze Insoluble Particulate Matter in Ice Cores, and Its Application to Diatom Sampling in the Antarctic Peninsula",
    year = "2021",
    journal = "Frontiers in Earth Science",
    abstract = "The insoluble particulate matter deposited on ice sheets provide key information to reconstruct past climate. The low concentration of some insoluble particulate matter, such as terrigenous particles and microfossils, challenges the efficiency of the recovery and the representativeness of the results. Here we present a new optimized method to extract, quantify and classify targeted low concentration insoluble particulate matter. Particle recovery rates and particle distribution were investigated using polystyrene particle standards filtered through Polycarbonate membrane filters and subsequently scanned in a scanning electron microscope. Experimental results in continuous and discrete sampling systems reveal consistent trends in the transport and removal of particulate material inside a filtration system. Statistical simulations are used to optimize the sample analyses required to achieve representative results. The analysis of diatoms in ice cores using this new method uncovered their potential to hold valuable climate records from the Antarctic Peninsula region. The data presented here evidence the presence of a measurable amount of marine diatoms with sub-annual variations, highlighting the potential of this record as a seasonal indicator. The new method presented provides an optimized and statistically representative approach for extracting, recovering and analyzing micrometre-sized, low-concentration insoluble particulate matter in ice.",
    url = "https://doi.org/10.3389/feart.2021.617043",
    doi = "10.3389/feart.2021.617043",
    openalex = "W3133663908",
    references = "doi101007978940178978318"
}

Pollution in pristine ecosystems is a high concern according that this research evaluates the occurrence of microplastics (MPs) in marine sediments from Mackellar and Martel Inlets in Admiralty Bay, King George Island, Antarctica. The samples were collected during January 2023. Colors and shape of MPs were determined by sampling points and compared with depth and distance to coast. MPs abundance ranged from 0 to 0.38 particles per-gram (mean 0.21, stand.dev. 0.13). Fibers were the dominant (92%), followed by fragments (8%). Concerning colors, blue (51.9%) and black (36.6%) were common. Particle sizes were within the 0.01-1 mm range, accounting for 73% of the total. Particles were analyzed by Raman spectroscopy, and two types of polymers were identified polyethylene terephthalate or PET (24%) and PET glycol (6%) the remained particles were undetermined due to their small size. The dispersion of blue and black particles with depth was high (r = 0.8) mainly in the deepest stations. While the dispersion of particles to the distance to coast was low representative, however seems to be some relevance to fibers more than for fragments. Our findings confirm the presence of synthetic particles in Antarctica a remote and fragile environment with unique ecological structure and dynamic, reinforcing the need for continued monitoring efforts and preventive measures to mitigate microplastic pollution. Sediment accumulation of MPs affects to the benthic communities but also to the entire marine food web as well as would alter its physical conditions. The isolated condition of Antarctica would increase the effect of anthropogenic pollutants.

@article{doi101016jmarpolbul2026119794,
    author = "Ayala-Ttupa, Cinthya and Vivanco-Barrientos, Fiorela and De-la-Torre, Gabriel and Santillán, Luis",
    title = "Dispersion assessment of microplastics in marine sediments from McKellar and Martel Inlets, King George Island, Antarctica.",
    year = "2026",
    journal = "Marine pollution bulletin",
    abstract = "Pollution in pristine ecosystems is a high concern according that this research evaluates the occurrence of microplastics (MPs) in marine sediments from Mackellar and Martel Inlets in Admiralty Bay, King George Island, Antarctica. The samples were collected during January 2023. Colors and shape of MPs were determined by sampling points and compared with depth and distance to coast. MPs abundance ranged from 0 to 0.38 particles per-gram (mean 0.21, stand.dev. 0.13). Fibers were the dominant (92\%), followed by fragments (8\%). Concerning colors, blue (51.9\%) and black (36.6\%) were common. Particle sizes were within the 0.01-1 mm range, accounting for 73\% of the total. Particles were analyzed by Raman spectroscopy, and two types of polymers were identified polyethylene terephthalate or PET (24\%) and PET glycol (6\%) the remained particles were undetermined due to their small size. The dispersion of blue and black particles with depth was high (r = 0.8) mainly in the deepest stations. While the dispersion of particles to the distance to coast was low representative, however seems to be some relevance to fibers more than for fragments. Our findings confirm the presence of synthetic particles in Antarctica a remote and fragile environment with unique ecological structure and dynamic, reinforcing the need for continued monitoring efforts and preventive measures to mitigate microplastic pollution. Sediment accumulation of MPs affects to the benthic communities but also to the entire marine food web as well as would alter its physical conditions. The isolated condition of Antarctica would increase the effect of anthropogenic pollutants.",
    url = "https://pubmed.ncbi.nlm.nih.gov/42030812/",
    doi = "10.1016/j.marpolbul.2026.119794",
    pmid = "42030812"
}

East-West Antarctic separation from ~43-11 Ma is well-documented through marine magnetic anomalies in the western Ross Sea, yet multiple lines of evidence suggest earlier extension, including Victoria Land uplift (~55-50 Ma) and reconstruction gaps between the Lord Howe Rise and Campbell Plateau. Here, we present marine magnetic data from the Central Basin between the Hallett Ridge and Iselin Bank revealing oceanic crust formed between Chrons 24-20 (~53-43 Ma), confirming earlier onset of East-West Antarctic motion. Forward modeling favors asymmetric extension as the preferred mechanism for forming the ~80 km wide Central Basin. This timing coincides with Transantarctic Mountains uplift and the termination of Tasman Sea spreading (~53 Ma), which redirected extensional forces southward along triple junction pathways into the Ross Sea. Our findings extend East-West Antarctic motion ~10 million years earlier than previously established, resolving the temporal discrepancy with Victoria Land uplift and reducing long-standing misfits in Southwest Pacific reconstructions.

@article{doi101038s4146702672500x,
    author = "Choi, Hakkyum and Kim, Seung-Sep and Kim, Sookwan and Choi, Hyunggyu and Park, Yongcheol and Park, Sung-Hyun and Davey, Fred J",
    title = "Revising the tectonic chronology of East-West Antarctica since the breakup of East Gondwana.",
    year = "2026",
    journal = "Nature communications",
    abstract = "East-West Antarctic separation from \textasciitilde 43-11 Ma is well-documented through marine magnetic anomalies in the western Ross Sea, yet multiple lines of evidence suggest earlier extension, including Victoria Land uplift (\textasciitilde 55-50 Ma) and reconstruction gaps between the Lord Howe Rise and Campbell Plateau. Here, we present marine magnetic data from the Central Basin between the Hallett Ridge and Iselin Bank revealing oceanic crust formed between Chrons 24-20 (\textasciitilde 53-43 Ma), confirming earlier onset of East-West Antarctic motion. Forward modeling favors asymmetric extension as the preferred mechanism for forming the \textasciitilde 80 km wide Central Basin. This timing coincides with Transantarctic Mountains uplift and the termination of Tasman Sea spreading (\textasciitilde 53 Ma), which redirected extensional forces southward along triple junction pathways into the Ross Sea. Our findings extend East-West Antarctic motion \textasciitilde 10 million years earlier than previously established, resolving the temporal discrepancy with Victoria Land uplift and reducing long-standing misfits in Southwest Pacific reconstructions.",
    url = "https://pubmed.ncbi.nlm.nih.gov/42034612/",
    doi = "10.1038/s41467-026-72500-x",
    pmid = "42034612"
}

Thwaites Glacier in West Antarctica is losing ice rapidly and is considered especially vulnerable to retreat, but predictions of its future remain limited by uncertainties about its subglacial properties. Here we show results from 344 km of vibroseismic surveys collected along and across the glacier. The data reveal a heterogeneous bed of elevated ridges with steep upstream-facing slopes that form crag-and-tail landforms resisting fast flow. Between these ridges lie basins filled with consolidated sediments. Subglacial water is widespread, occurring in bed depressions and on topographic highs, including an active lake composed of tens of metres of highly porous, water-saturated sediments. Across the glacier, the bed beneath the eastern margin is mostly hard but contains isolated pockets of softer material. These findings demonstrate current models do not capture the full complexity of the bed beneath Thwaites Glacier, where water-bearing sediments and steep basal slopes strongly affect ice flow and retreat.

@article{doi101038s43247026035022,
    author = "Zeising, Ole and Eisen, Olaf and Hofstede, Coen and Agnew, Ronan and Brisbourne, Alex and Hoffman, Andrew O and Anandakrishnan, Sridhar",
    title = "Hard rocks and deep wetlands beneath Thwaites Glacier in Antarctica.",
    year = "2026",
    journal = "Communications earth \& environment",
    abstract = "Thwaites Glacier in West Antarctica is losing ice rapidly and is considered especially vulnerable to retreat, but predictions of its future remain limited by uncertainties about its subglacial properties. Here we show results from 344 km of vibroseismic surveys collected along and across the glacier. The data reveal a heterogeneous bed of elevated ridges with steep upstream-facing slopes that form crag-and-tail landforms resisting fast flow. Between these ridges lie basins filled with consolidated sediments. Subglacial water is widespread, occurring in bed depressions and on topographic highs, including an active lake composed of tens of metres of highly porous, water-saturated sediments. Across the glacier, the bed beneath the eastern margin is mostly hard but contains isolated pockets of softer material. These findings demonstrate current models do not capture the full complexity of the bed beneath Thwaites Glacier, where water-bearing sediments and steep basal slopes strongly affect ice flow and retreat.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13109048/",
    doi = "10.1038/s43247-026-03502-2",
    pmcid = "PMC13109048",
    pmid = "42039916"
}

Ice-sheet models require explicit knowledge of the underlying bed. However, much remains unknown regarding the subglacial environment owing to difficulties associated with measuring it. Extensive radar surveys have been conducted across Antarctica, but the requirement of full-coverage bed topography for models necessitates interpolation over gaps between existing observations, which often span kilometres or more. Advances in modelling capabilities now allow for the application of dynamic coupling between subglacial hydrology and ice dynamics in models of Antarctica. While a bed resolution of approximately 1 km is recommended for modelling Antarctic ice dynamics, it has been suggested that finer spatial resolutions are necessary to resolve subglacial water flow. We use a coupled model configuration to generate projections of glacier evolution, including the subglacial hydrologic system, for Thwaites Glacier, West Antarctica, initiated with several different bed topographies. We find that the specific bed topography has a first-order control on accumulated mass loss, but that final sea-level rise does not scale with bed resolution. We also find that coupling between subglacial hydrology and ice dynamics results in faster mass loss. Our results underscore the importance of continued high-resolution topography mapping and suggest that current projections may underestimate uncertainty linked to unresolved bed features. This article is part of the Theo Murphy meeting issue 'Next generation ice-sheet bed measurements'.

@article{doi101098rsta20240545,
    author = "Ehrenfeucht, Shivani and Dow, Christine",
    title = "Impacts of bed topography resolution on sea-level rise projections from coupled subglacial hydrology and ice dynamics for Thwaites Glacier, Antarctica.",
    year = "2026",
    journal = "Philosophical transactions. Series A, Mathematical, physical, and engineering sciences",
    abstract = "Ice-sheet models require explicit knowledge of the underlying bed. However, much remains unknown regarding the subglacial environment owing to difficulties associated with measuring it. Extensive radar surveys have been conducted across Antarctica, but the requirement of full-coverage bed topography for models necessitates interpolation over gaps between existing observations, which often span kilometres or more. Advances in modelling capabilities now allow for the application of dynamic coupling between subglacial hydrology and ice dynamics in models of Antarctica. While a bed resolution of approximately 1 km is recommended for modelling Antarctic ice dynamics, it has been suggested that finer spatial resolutions are necessary to resolve subglacial water flow. We use a coupled model configuration to generate projections of glacier evolution, including the subglacial hydrologic system, for Thwaites Glacier, West Antarctica, initiated with several different bed topographies. We find that the specific bed topography has a first-order control on accumulated mass loss, but that final sea-level rise does not scale with bed resolution. We also find that coupling between subglacial hydrology and ice dynamics results in faster mass loss. Our results underscore the importance of continued high-resolution topography mapping and suggest that current projections may underestimate uncertainty linked to unresolved bed features. This article is part of the Theo Murphy meeting issue 'Next generation ice-sheet bed measurements'.",
    url = "https://pubmed.ncbi.nlm.nih.gov/42021661/",
    doi = "10.1098/rsta.2024.0545",
    pmid = "42021661"
}

@misc{crossrefNoneantarctica,
    title = "Antarctica",
    year = "None",
    booktitle = "AccessScience",
    url = "https://doi.org/10.1036/1097-8542.038000",
    doi = "10.1036/1097-8542.038000"
}