IS A supervolcano brewing beneath Mount St Helens? Peering under the volcano has revealed what may be an extraordinarily large zone of semi-molten rock, which would be capable of feeding a giant eruption.
Magma can be detected with a technique called magnetotellurics, which builds up a picture of what lies underground by measuring fluctuations in electric and magnetic fields at the surface. The fields fluctuate in response to electric currents travelling below the surface, induced by lightning storms and other phenomena. The currents are stronger when magma is present, since it is a better conductor than solid rock.
Supervolcano may be brewing beneath Mount St Helens - environment - 10 June 2009 - New Scientist
I've got a question to pose. I'm an old ex geology major from the 1960's.
Illrelevant I suppose, but I've been thinking. Recently, scientist have discovered an even larger magma chamber beneath Yellowstone, and now they are finding a large magma chamber beneath Mt. St. Helen's. Hawaii is a hot spot and there are some hot spots in Asia. Wouldn't it be interesting if they discover that there are these large magma chambers beneath many or most of the large volcanoes around the world?
And what if many of the dormant, extinct volcanoes have magma chambers beneath them? Austin, TX has a dormant volcano (Pilot Knob) on the southeast side of town. It lay at the bottom of the ocean when Austin was under water during Creteaceous.
Just some weird thoughts.