The potential for earthquakes as a result of snow disappearance

Heki, K., Science, 293, 89-92, 2001.
Heki, K., Earth Planet. Sci. Lett., 207, 159-164, 2003.

Seasonal features observed in GPS site coordinate time series in Japan can often be explained by snow loads along the Sea of Japan side of the country’s backbone mountains. Snow loads reduce Coulomb failure stress by "clamping" faults (i.e., increasing compression normal to the fault plane). Spring thaw may thus trigger inland earthquakes, which is consistent with the observation that disastrous tremors in Japan have historically tended to occur more in spring and summer (the panel on the right is from an article published in the Asahi Newspaper). Snow plays the role of a keystone that reduces underground movement (left panel).