Connecting the Dots: Climate Change drives Earthquake / Seismic activity
Richard Pauli wrote on his blog Climate Daily, back in 2009: Earthquakes, tsunamis, and volcanoes. Something real, something hard, fast, and impossible to ignore. Increasing evidence and statistical analysis links increased seismic activity to global warming.
Post-glacial rebound (sometimes called continental rebound, glacial isostatic adjustment) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostasy. It affects northern Europe (especially Scotland, Fennoscandia and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, parts of Patagonia, and Antarctica.
Source Isostatic Rebound
This alarming notion was first discussed in 1998 and is now more widely mentioned in university studies and recent publications – from the Journal of Geodynamics to National Geographic, to blogs reporting opinions of scientists (below).
Some intuitive calculation may help understanding: A cubic yard of ice weighs nearly a ton. The Antarctic ice sheet is a few miles thick. Earth adjusted to that immense weight over the millennia – now, as ice caps melt, this weight is slowly lifting..
Today the Pine Island Glacier in Antarctica is quickly melting downward from the surface – dropping in altitude at nearly 16 meters per year. With an area over 5 thousand square kilometers, this glacier holds a lot of cubic meters of ice and means that a lot of weight is now getting shifted into the ocean. Similarly, the melting of glaciers in Greenland and elsewhere will trigger seismically elastic reactions that should be noted for their frequency, intensity and novel locations.
This idea is consistent for our age: The Anthropocene Epoch – a geological age where humans make a significant impact. Who knew that human industrial CO2 emissions warming the atmosphere then melting the ice and then the shifting weight would provoke such a rapid and palpable reaction. Such a sudden, fast impact of global warming has so far been missing from this crisis. Source Climate Daily
Since Richard Pauli wrote about the climate change link to the Geosphere, the Royal Society (founded 1660) run a special coverage of the topic to assess the various implications. They came to the conclusion that Climate forcing of geological and geomorphological hazards pose significant threats:
..evidence for periods of exceptional past climate change eliciting a dynamic response from the Earth’s crust, involving enhanced levels of potentially hazardous geological and geomorphological activity. The response, McGuire notes, is expressed through the triggering, adjustment or modulation of a range of crustal and surface processes, which include gas-hydrate destabilization, submarine and subaerial landslides, debris flows and glacial outburst floods, and volcanic and seismic activity.
Joe Romm from Climate Progress run the story back in april 2010
Royal Society Stunner: “Observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere.”
Periods of exceptional climate change in Earth history are associated with a dynamic response from the solid Earth, involving enhanced levels of potentially hazardous geological and geomorphological activity. This response is expressed through the adjustment, modulation or triggering of a wide range of surface and crustal phenomena, including volcanic and seismic activity, submarine and sub-aerial landslides, tsunamis and landslide ‘splash’ waves glacial outburst and rock-dam failure floods, debris flows and gas-hydrate destabilisation. Looking ahead, modelling studies and projection of current trends point towards increased risk in relation to a spectrum of geological and geomorphological hazards in a world warmed by anthropogenic climate change, while observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere.
An older study from 1997 concluded
“..study that was published in the journal Nature in 1997 that looked at the connection between the change in the rate of sea level rise and volcanic activity in the Mediterranean for the past 80,000 years and found that when sea level rose quickly, more volcanic eruptions occurred, increasing by a whopping 300 percent.”
The media has to cover these aspects and risks from climate change as well. The implications may be catastrophic, which means that we have to deal with the threat of the climate change seriously. Hence starting to reduce our impacts to slow the development of AGW induced climate change as fast as possible.
Monsoons spinning the Earth’s plates: study
Scientists have for the first time shown a link between intensifying climate events and tectonic plate movement in findings that could provide a valuable insight into why huge tremors occur.
“The 100km-thick outer shell of Earth, the lithosphere, is divided into pieces called tectonic plates. Plates move in different directions at speeds in the order of centimetres per year, comparable to the speed of fingernail growth in humans.
“The significance of this finding lies in recognising for the first time that long-term climate changes have the potential to act as a force and influence the motion of tectonic plates. It is known that certain geologic events caused by plate motions – for example the drift of continents, the closure of ocean basins and the building of large mountain belts – have the ability to influence climate patterns over a period of a million years.
“Now we know that the opposite holds as well: long-term climate change, or the natural changes in climate patterns over millions of years, can modify the motion of plates in a feedback mechanism.”
Dr Iaffaldano added that the finding could help unlock the causes of plate-motion events like large-scale earthquakes.
“When forces moving plates along their boundaries reach certain thresholds, earthquakes occur and energy is released. This happens cyclically, typically every several hundred years in the case of large earthquakes. However it appears that the seismic potential of plate boundaries, which is an indication of how prone these are to large earthquakes, depends, among other factors, also on how strong or weak these forces have been in the past. In other words, it depends also on the history of plates over millions of years.
“In order to understand the seismic potential of plate boundaries it is important to identify all the possible factors that caused plate motion to change in the past. In that respect we have discovered that climate change could in fact be one possible candidate, something we did not consider until now.
Notice: The human race emitting today 10.000 faster Co2 then during the PETM, and this process accelerates further. Tectonics which are prone since the last major geospheric shift around 55 million years ago could literally “wake up”.
Further reading Geomorphic Responses to Climatic Change – a 1991 book by W. B. Bull Active Tectonics
Pedology is the study of soils in their natural environment. Soils lie at the interface of Earth’s atmosphere, biosphere, hydrosphere and lithosphere. Therefore, a thorough understanding of soils requires some knowledge of meteorology, climatology, ecology, biology, hydrology, geomorphology, geology and many other earth sciences and natural sciences.