Strong Grimsvötn volcanic eruption may indicate a shorter activity phase
(24 May 2011)
Following new eruptions from Iceland's most active volcano, Grimsvötn, a leading earth scientist at Durham University says that the relative strength of the initial eruption of the Grimsvötn volcano may mean a shorter duration and less disruption.
The volcano, which lies under the Vatnajokull glacier in south-east Iceland, last erupted in 2004.
Grimsvötn (trans: "Grim's lakes") is a central volcano in the middle of Vatnajökull (trans: "Water glacier") - the largest icecap in Europe.
This new volcanic activity follows last year's eruption of Iceland's Eyjafjallajokull volcano. Then, plumes of ash caused weeks of air travel chaos across Europe.
Professor Gillian Foulger said: "This eruption is bigger and more spectacular than the Eyjafjallajökull eruption. Its gigantic initial volcanic plume (20 km high) suggests that it may exhaust itself and cease quicker than the Eyjafjallajökull eruption, but only time will tell.
"Grimsvötn is a remarkable and unique volcano. It has a 4000-MW natural geothermal area, which has melted a permanent hole in the icecap there. Three buildings that comprise a research station are built on this bare patch of ice-free ground.
"The geothermal area melts ice and snow, progressively filling a large caldera lake there. This lake periodically drains to the south, causing so-called "hlaups" (trans: "run"), or floods of water from the southern rim of the ice cap to the sea.
"Like Eyjafjallajökull (trans: "Island mountain glacier"), which erupted last year, it is a so-called "central volcano" - a volcano that erupts at a central site. This contrasts with the other sort of volcano - the "fissure volcano" that erupts along a long fissure in the ground.
"Japan is an example of a country with many central volcanoes. Hawaii is an example of a place with many fissure volcanoes. Iceland has both.
"The central volcanoes of Iceland typically give almost no warning they are about to erupt, and this eruption is no exception. Nowadays, scientists telemeter data in real time down from Iceland's volcanoes, and we find that often volcanic tremor begins a few hours before the eruption starts. However, there is at present no way to reliably predict this sort of eruption in Iceland with more warning than this."
Dr Claire Horwell, RCUK Fellow in the Department of Earth Sciences, Durham University, is part of an international group of experts on volcanic ash and health.
Expert members of IVHHN work in diverse scientific disciplines such as volcanology, epidemiology, toxicology, public health and physical chemistry with a common aim of trying to determine the health effects of volcanic emissions, in particular the health hazard of inhaling volcanic ash and gas.
For information and updates on volcanic ash and health please click on the following link: The International Volcanic Health Hazard Network (IVHHN).