Climate Change Can Increase Volcanic Activity

A new study claims that rapid glacial melting and the rise in sea levels could result in a significant rise in volcanic eruptions.

Earlier studies have suggested that volcanic eruptions can alter the Earth's climate for short and long periods of time.

But a team of researchers from GEOMAR - Helmholtz Centre for Ocean Research Kiel in Germany and Harvard University have found that rapid climate change in the last one million years caused rapid melting of glaciers and increase in sea levels. This resulted in the rise in volcanic eruptions, according to LiveScience.

The research team analyzed the sediment cores drilled from the oceans off South and Central America. The cores gave insight into the history of Earth's climate for the past one million years.

Based on their observations of ash layers that appeared in the sediment cores, experts reconstructed the history of volcanic eruptions in the last 460,000 years. "There were periods when we found significantly more large eruptions than in others," lead author Dr. Steffen Kutterolf, a GEOMAR volcanologist, said in a statement.

When researchers compared the patterns of volcanic activity with the Earth's climate history, they found that the periods of large volcanic eruptions followed an increase in global temperatures, rapid melting of glaciers and rise in sea levels.

In some regions such as Costa Rica, volcanic activity was higher during periods of rapid glacial melting and sea level rise. Using a computer model, the research team found that rapid glacial melting decreases the pressure on the continents, whereas increasing sea level puts in more pressure on the ocean floor crust.

"In times of global warming, the glaciers are melting on the continents relatively quickly. At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. Thus, the stress changes withinin the earth to open more routes for ascending magma," said Marion Jegen, a geophysicist at GEOMAR.

It is not clear if man-made warming will have a similar impact on volcanic eruptions. Even if human-caused climate change impacts volcanic activity, the effect would not be seen for centuries as volcanic eruptions do not occur instantly after climate change, Jegen told LiveScience.

The findings of the study are published in the journal Geology.