Sesia Valley's unprecedented exposure of magmatic plumbing provides a model for interpreting geophysical profiles and magmatic processes beneath active calderas. The exposure also serves as direct confirmation of the cause-and-effect link between molten rock moving through the Earth's crust and explosive volcanism.
"It might lead to a better interpretation of monitoring data and improved prediction of eruptions," says Quick, lead author of the research article reporting the discovery, "Magmatic plumbing of a large Permian caldera exposed to a depth of 25 km.," in Geology.
Calderas, which typically exhibit high levels of seismic and hydrothermal activity, often swell, suggesting movement of fluids beneath the surface.
"We want to better understand the tell-tale signs that a caldera is advancing to eruption so that we can improve warnings and avoid false alerts," Quick says.
To date, scientists have been able to study exposed caldera "plumbing" from the surface of the Earth to a depth of only 5 kilometers. Because of that, scientific understanding has been limited to geophysical data and analysis of erupted volcanic rocks. Quick likens the relevance of Sesia Valley to seeing bones and muscle inside the human body for the first time after previously envisioning human anatomy on the basis of a sonogram only.
"We think of the Sesia Valley find as the 'Rosetta Stone' for supervolcanoes because the depth to which rocks are exposed will help us to link the geologic and geophysical data," Quick says. "This is a very rare spot. The base of the Earth's crust is turned up on edge. It was created when Africa and Europe began colliding about 30 million years ago and the crust o
|Contact: Kim Cobb|
Southern Methodist University