Climate Change’s Sea Level Rise and Coastal Earthquakes
Contributed by West Coast Climate Equity Advisor Professor William H. Calvin
The 8.8 EQ on Chile’s coastline is a reminder of what we might see more frequently as the sea level rises in coastal areas already susceptible to large EQs, both in the Pacific Ocean’s “Ring of Fire” and in island volcano settings such as the Canary Islands and those of the Caribbean.
In such areas where EQs are common near coastlines, the fault lines are in an uneasy balance that occasionally slips. The overburden on such faults includes all of the rock and soils on the land side and a mix of hydrostatic pressure and sediments on the ocean side. As sea level rises with ice melt from global overheating, ocean faults experience symmetrical hydrostatic pressures increases on both sides of a fault. But near land, the increase is asymmetrical with only the ocean side experiencing an increase in overburden.
Because of the asymmetrical change, one would expect a period of adjustment where EQs in coastal zones became more common than at present.
Note from Dorothy: Please check Professor Calvin’s website for his books, articles and an excellent slide show.