[Rockhounds] CAT scan reveals inner workings of volcano island

[Kreigh Tomaszewski]

On the ground and in the water, an international team of researchers 
has been collecting imaging data on the Soufriere Hills Volcano in 
Montserrat to understand the internal structure of the volcano and how 
and when it erupts.

  "Using land-based measurement, we can see that over the time periods 
when the magma is erupting, the ground surface deflates into a bowl of 
subsidence and when the magma is sealed underground, the ground surface 
inflates like a balloon," says Barry Voight, professor emeritus of 
geosciences, Penn State. "The interesting thing is that much more magma 
is erupting than appears represented by the subsiding bowl."

  Voight suggests a simple model to explain this discrepancy seen 
through the various eruptive phases and pauses of the volcano.

http://live.psu.edu/story/36501