The eruption can cause climate change, no doubt. Supervolcanoes that send to the stratosphere many tons of ash may affect the global climate. But it appears that perhaps the reverse effect: the German and American scientists have found evidence that climate can change the activity of volcanoes.
This is something new! However, researchers at Harvard University in collaboration with the center GEOMAR know what they say on their side - the results of the analysis of volcanic deposits in the last million years.
The work itself began over ten years ago and focused on intensive studies of volcanoes in Central America. "Among other evidence, we have samples of ancient layers of volcanic ash, which allowed to reconstruct the history of eruptions over the past 460,000 years - said one of the authors of the work. - And in them are the periods in which the eruption was much more than the others. "
Thus, the samples can be seen, how the volcanic activity during this time. When the researchers compared the course of these changes to the climate history data available, the agreement was "amazing." Periods of high volcanic activity followed the rise in temperature and the melting of glaciers - or more precisely, with the Milankovitch cycles that show periodic oscillations in the amount of sunlight reaching the Earth's surface, and are associated with the peculiarities of motion of the planet in its orbit.
More research, scientists have been on samples recovered from the bottom of the Pacific Ocean. They allowed to "look" in the past is to 1 million years - and discovered exactly the same picture. It remains only to assume, which explains the possible impact.
According to the authors, the reason for all - a global temperature rise, which leads to the rapid melting of continental glaciers and increasing sea levels. Weight continents as a result becomes less and the mass of water that pushes the ocean floor plate, however, is growing. The Earth's crust is under stress and strain, which opens in her new "weak points", is supplied under pressure upward currents of magma.
Incidentally, during periods of global cooling, volcanic activity on the growth observed. Scientists believe that the reason for this - the slower the flow of this process, so that sufficiently high stress does not occur.