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.
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