It may be the largest ever discovered on the continent

Oct 26, 2009 13:16 GMT  ·  By

Geologists recently announced that there might be more things that Mount St. Helens, Mount Rainier and Mount Adams have in common, other than the fact that they are all volcanoes. Preliminary studies seem to indicate that they draw their lava from the same enormous magma pool that spans the entire southwestern portion of Washington state. The science team that conducted the investigation revealed in the October 25 issue of the journal Nature Geoscience that the setup in Washington might be similar to the one known to exist under the Yellowstone supervolcano, LiveScience reports.

“If confirmed by additional methods, this could be one of most widespread magma-bearing areas of continental crust discovered thus far,” the journal entry reads. The leader of the new investigation was geologist Graham Hill, from GNS Science, in New Zealand. He and his team used advanced measuring techniques to assess the electrical conductivity of rocks that lay beneath the northern Cascade Mountain range, and discovered that previous speculations, which held that a layer of low electrical conductivity permeated the entire region, were true. The three volcanoes are indeed connected.

The team's measurements led the experts to conclude that “fingers,” or filaments, from this layer headed towards the surface, just underneath Mount St. Helens, and Mount Adams. The lower electrical conductivity, geologists know, is characteristic of regions rich in molten rock, as hard rock conduces electricity far better than magma does. The investigation therefore seems to hint at the fact that, under the continental crust, a large pool of semi-molten rock may have formed, spanning the area below all the three volcanoes. These filaments may be contributing to an increased level of volcanic activity.

“Their interpretation is open to disagreement. Other geophysical studies don't support this theory,” Seth Moran says, quoted by McClatchy Newspapers. The scientist is a volcano seismologist with the US Geological Service (USGS) Cascades Volcano Observatory, in Vancouver, Washington. A significant number of new studies has forwarded in the past few months our understanding of supervolcanoes. Especially useful was the discovery of a new supervolcano in the Italian Alps, which last blew its top off some 280 million years ago.

Knowing as much as possible about volcanoes is crucial, as the US has Yellowstone on its territory. If the massive mountain explodes, it could cover over half of the country's surface in three feet (one meter) of ash, and cause an unbelievably large damage, according to a study. It's currently estimated that the supervolcano erupts once every 600,000 years, so, for now, we are safe, but the Earth's magma flows can be unpredictable, scientists say.