Climate Change and the Unexpected: Earthquakes, Tsunamis, Volcanoes

The recent discovery of 91 volcanoes under the ice (Guardian Weekly 18.8) corresponds with these areas of West Antarctic ice loss

I have been aware that changes on the earth’s surface may cause earthquakes or volcanic activity for some time. A seismologist once pointed out to me that the increased weight of water of a new dam could easily trigger one. More than 3 years ago I noted in an addendum to an article on Gippsland Sea Level Rise that melting ice on the West Antarctic Peninsula was causing the land underneath to rise, distort and deform, possibly leading to increased volcanic activity under the ice which in turn could vastly accelerate ice melt and sea level rise.

Recently there has been some tweets on the social media associating the spate of hurricanes with the earthquakes in Mexico which I thought far-fetched and so completely ignored. However I have just come across an old article in the Guardian by Professor Bill McGuire of the University of California on precisely this topic.

McGuire noted an association between large earthquakes and typhoons. He cited research in Taiwan that documented earthquakes following the passing of a typhoon. The authors explained that the reduced air pressure in the typhoons was enough to allow the underlying faults in the earth’s crust to move more easily. The analogy used was that the energy at the fault lines is like a coiled up spring waiting for a trigger to set it off. He states: “It is possible that floodwaters are lubricating fault planes” and notes another researcher, Wdowinski, “thinks that the erosion of landslides caused by the torrential rains acts to reduce the weight on any fault below, allowing it to move more easily.” McGuire noted the likelihood of increased volcanic activity with climate change and also looked at Tsunamis caused by vast undersea landslips.

He continued: “If today’s weather can bring forth earthquakes and magma from the Earth’s crust, it doesn’t take much to imagine how the solid Earth is likely to respond to the large-scale environmental adjustments that accompany rapid climate change…The last time our world experienced serious warming was at the end of the last ice age when, between about 20,000 and 10,000 years ago, temperatures rose by six degrees centigrade, melting the great continental ice sheets and pushing up sea levels by more than 120m. These huge changes triggered geological mayhem. As the kilometres-thick Scandinavian ice sheet vanished, the faults beneath released the accumulated strain of tens of millennia, spawning massive magnitude eight earthquakes.”

His conclusion is “that as climate change tightens its grip, we must be prepared to expect the unexpected”. I hope to look at McGuire’s book Waking the Giant in some detail in the near future. And the social media’s association of the Mexican earthquakes with Hurricane Harvey and tropical storm Norma is perhaps not so far-fetched after all.