December 19, 2012
Does Melting Ice Cause Volcanic Eruptions?
Michael Harper for redOrbit.com — Your Universe Online
For every action, there is an equal and opposite reaction. This fact holds true in a myriad of situations from physics to our global climate. Numerous studies have shown even the smallest change in an ecosystem can affect seemingly unrelated aspects to the same area.
Today, German researchers along with researchers from Harvard University in Cambridge, Massachusetts have published a study detailing how global ice affects volcanoes.
While it´s long been understood a volcanic eruption can bring about a short period of cooler climates, this new study shows this cause-and-effect plays out on a much larger and longer stage.
After studying data from over a million years in our Earth´s history, researchers at GEOMAR Helmholtz Center for Ocean Research Kiel in Germany and Harvard University have discovered periods of high volcanic activity often follow periods of quickly rising global temperatures.
To best display this trend, these researchers looked to data collected as a part of the Collaborative Research Center “Fluids and Volatiles in Subduction Zones (SFB 574).”
This project has been gathering data from the volcanoes of Central America for more than 10 years.
"Among others pieces of evidence, we have observations of ash layers in the seabed and have reconstructed the history of volcanic eruptions for the past 460,000 years," said Dr. Steffen Kutterolf, a volcanologist with GEOMAR in Germany.
"There were periods when we found significantly more large eruptions than in others" explained Kutterolf, who acted as the lead author for the corresponding paper which has been published in the latest issue of the journal Geology.
After looking at the data, the researchers noticed periods of high volcanic activity always follow a period of fast global temperature increases. This global warming in turn leads to a rapid melting of the world´s ice.
Looking for even more evidence, the teams expanded their research to cores taken from the entirety of the Pacific region. These samples had been collected as a part of the International Integrated Ocean Drilling Program (IODP) as well as earlier programs. These samples provide a history of the Earth more than 1 million years ago. According to Dr. Marion Jegen from GEOMAR, who also participated in the study, these Pacific samples confirmed what the Central American samples had shown. To explain the relationship, the GEOMAR and Harvard teams plugged this evidence into some geological computer models.
"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 within in the earth to open more routes for ascending magma" explained Dr. Jegen.
"If you follow the natural climate cycles, we are currently at the end of a really warm phase. Therefore, things are volcanically quieter now. The impact from man-made warming is still unclear based on our current understanding" said Dr. Kutterolf.
The team now plans to investigate the short term variations to better understand how these changes will affect us in the modern day.