A new study published in the journal Geology suggests the rapid rise in sea levels might cause a dramatic increase in volcano eruptions. Scientists studied periods of rapid climate change over the last million years. They found that, when continental glaciers rapidly melted, it caused the sea-level to rise and eventually increased volcanic eruptions.
The study’s co-author Marion Jegen, a geophysicist at Geomar in Germany, said, “Everybody knows that volcanoes have an impact on climate. What we found was just the opposite.” She added that the findings were based only on natural changes in climate, not climate change due to humans. This makes it was unclear if human based climate change would have the same effects and if it did it would not be seen for centuries, according to Yahoo News.
Scientists have known volcanism can alter the climate dramatically. But few thought climate change could cause volcanic eruptions. The scientist studied cores drilled from the oceans of South and Central America. The samples showed the last 1 million years of the Earth’s climate history. Shifts in the Earth’s orbit led to rapid warming and massive glaciers melting resulting in a quick rise of sea levels. The scientists found more layers of volcanic ash, or tephra, in the sediment cores after the shifts. Jegen told Live Science some places like Costa Rica saw five to 10 more times as much volcanic activity during period of glacial melting as other times.
Then scientists used a computer model to show how the changes affected the pressures experienced at different places on the Earth’s crust. The model showed that the change in pressure seemed to cause an increase in volcanism. Jegen said that, in general, the speed of the transition from ice age to melting, rather than the total amount of melting, predicted how intensely the volcanic eruptions increased.
Jegen told Live Science, “We predict there’s a time lag of about 2,500 years. So even if we change the climate, you wouldn’t really expect anything to happen in the next few thousand years.”