Moonquakes can be explained by tidal stresses and by lunar contraction
(due to the highlands gradually sinking). Moonquakes, in fact, provide
evidence that the moon has a solid core, consistent with its old age.
There is no evidence for recent lava flows not associated with meteor
impacts.
Outgassing is consistent with an old moon. It can take a long time for
gasses to work their way to the surface.
