Possible Seismogenic-Trigger Mechanism of Methane Emission, Glacier Destruction and Climate Warming in the Arctic and Antarctic

Abstract

Abstract-A seismogenic-trigger mechanism is proposed for the activation of methane emission on the Arctic shelf in the late 1970s, which caused the onset of a rapid climate warming in the Arctic, as well as the intensive destruction of the ice shelves of West Antarctica in the late 20th and early 21st centuries. This process is accompanied by the release of methane from the underlying hydrate-bearing sedimentary rocks and the rapid climate warming in Antarctica. The proposed mechanism is associated with the action of deformation tectonic waves in the lithosphere-asthenosphere system, caused by strong earthquakes occurring in the subduction zones closest to the polar regions: the Aleutian, located in the northern part of the Pacific Ocean, and the Chilean and Kermadec-Macquarie, located in the southeastern and southwestern parts of the Pacific lithosphere. Disturbances of the lithosphere are transmitted at an average speed of about 100 km/year over long distances of the order of 2000–4000 km, and the associated additional stresses that come to the Arctic and Antarctica several decades after earthquakes lead to the destruction of metastable gas hydrates located in the frozen rocks of the Arctic shelf or in the subglacial sedimentary rocks of Antarctica, causing the greenhouse effect of warming. Moreover, transmission of additional stresses causes a decrease in the adhesion of sheet glaciers to the underlying rocks, their accelerated sliding and the destruction of the ice sheet ice shelves in Antarctica. The considered hypothesis leads to the conclusion that in the coming decades, the processes of glacier destruction and climate warming in Antarctica will increase due to an unprecedented increase in the number of strongest earthquakes in the subduction zones of the South Pacific Ocean in the late 20th and early 21st centuries.