Melting ice caps may trigger more volcanic eruptions in future

April 4th, 2008 - 12:42 pm ICT by admin  

London, April 4 (ANI): A new research has stated that melting ice caps, which are caused by global warming, may trigger more volcanic eruptions in the future.

According to a report in New Scientist, Carolina Pagli of the University of Leeds, UK, and Freysteinn Sigmundsson of the University of Iceland carried out the research.

For the research, they calculated the effects of the melting on the crust and magma underneath the Vatnajokull, which is the largest ice cap in Iceland, and is disappearing at a rate of 5 cubic kilometers per year.

According to the researchers, as the ice disappears, it relieves the pressure exerted on the rocks deep under the ice sheet, increasing the rate at which it melts into magma.

An average of 1.4 cubic kilometers has been produced every century since 1890, a 10% increase on the background rate.

In Iceland, there are several active volcanoes under the ice. The last big eruption was in 1996 at Gjalp, and before then in 1938 a gap of 58 years.

But Pagli and Sigmundsson have said that the extra magma produced as the ice cap melts could supply enough magma for similar eruptions to take place every 30 years on average.

The situation in Iceland does not necessarily mean magma will be melting faster around the world.

Vatnajokull sits atop a boundary between plates in the Earths crust, and it is this configuration that is allowing the release in pressure to have such a great effect deep in the mantle.

But the thinning ice has another effect on volcanoes that will be more widespread.

As the amount of weight on the crust changes, geological stresses inside the crust will also change, increasing the likelihood of eruptions.

Under the ices weight, the crust bends and as you melt the ice the crust will bounce up again, explained Bill McGuire of University College London in the UK.

According to Pagli, places likely to be at increased risk of eruption due to ice-melt include Antarcticas Mount Erebus, the Aleutian Islands and other Alaskan volcanoes.

We are going to see a massive increase in volcanic activity globally, McGuire told New Scientist. If we look back at previous warm periods, that is what happened, he added. (ANI)

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