Earthquakes are to Blame for the Warming of the Arctic

Фото: Кирилл Уютнов, участник фотоконкурса РГО "Самая красивая страна"

A new hypothesis explaining the rapid warming of the Arctic is connected with the influence of a series of large earthquakes that occur in the seismically active Aleutian Arc. The hypothesis was proposed by Leopold Lobkovsky, head of the Laboratory for Geophysical Research of the Arctic and Continental Margins of the World Ocean at MIPT. The researcher's article was published in the journal Geosciences.

The search for the reasons of the rapid warming of the Arctic region should be at the bottom of the Pacific Ocean, the scientist believes. The Aleutian Arc, stretching across the north of the Pacific, is the closest to the Arctic zone of powerful seismic activity. A series of large earthquakes in the earth's crust along the Aleutian Arc generates not only oceanic tsunamis, but also underground tectonic waves that propagate to the Arctic shelf. Lithosphere disturbance waves, entering the shelf zone, create additional stress there, which causes destruction of the internal structure of frozen rocks and gas hydrates containing methane. As a result, gas is released into the water and the atmosphere, which leads to an increase in temperature due to the greenhouse effect.

There are two periods of rapid warming in the history of the Arctic region: 1920s – 1930s and 1980 –– to the present. Both of these periods are marked by high seismic activity. The scientist compared the dates of the strongest earthquakes and jumps in the average annual temperature. It turned out that in the last century in the Aleutian Arc there were two series of strongest earthquakes, which occurred approximately 15–20 years before the start of the rapid warming. This time gap is explained by the speed of propagation of tectonic waves –  about 100 km per year. The Aleutian Arc is separated by 2 thousand km from the Arctic shelf zone. The lithospheric wave, spreading from the epicenter of the tremors, will cover this distance in just such a period.

"There is a clear correlation between the strongest earthquakes in the Aleutian Arc and the phases of climate warming. There is a mechanism for the physical transfer of stress in the lithosphere at the required rate, which creates conditions for the release of methane on the shelf. Additional stress destroys gas hydrates and frozen rocks, releasing methane. Three components of this concept are quite logical and amenable to mathematical and physical substantiation. And the concept itself successfully explains a specific fact – the rapid growth of temperature anomalies in the Arctic – which was not explained in previously existing models," emphasizes Leopold Lobkovsky.