Heat from below Pacific Ocean fuels Yellowstone, study finds
Date:
December 18, 2017
Source:
University of Illinois at Urbana-Champaign
Summary:
Recent stories in the national media are magnifying fears of a catastrophic eruption of the Yellowstone volcanic area, but scientists remain uncertain about the likelihood of such an event. To better understand the region's subsurface geology, geologists have rewound and played back a portion of its geologic history, finding that Yellowstone volcanism is more far more complex and dynamic than previously thought.
Recent stories in the national media are magnifying fears of a catastrophic eruption of the Yellowstone volcanic area, but scientists remain uncertain about the likelihood of such an event. To better understand the region's subsurface geology, University of Illinois geologists have rewound and played back a portion of its geologic history, finding that Yellowstone volcanism is more far more complex and dynamic than previously thought.
"The heat needed to drive volcanism usually occurs in areas where tectonic plates meet and one slab of crust slides, or subducts, under another. However, Yellowstone and other volcanic areas of the inland western U.S. are far away from the active plate boundaries along the west coast," said geology professor Lijun Liu who led the new research. "In these inland cases, a deep-seated heat source known as a mantle plume is suspected of driving crustal melting and surface volcanism."
In the new study, reported in the journal Nature Geosciences, Liu and graduate students Quan Zhou and Jiashun Hu used a technique called seismic tomography to peer deep into the subsurface of the western U.S. and piece together the geologic history behind the volcanism. Using supercomputers, the team ran different tectonic scenarios to observe a range of possible geologic histories for the western U.S. over the past 20 million years. The effort yielded little support for the traditional mantle plume hypothesis.
"Our goal is to develop a model that matches up with what we see both below ground and on the surface today," Zhou said. "We call it a hybrid geodynamic model because most of the earlier models either start with an initial condition and move forward, or start with the current conditions and move backward. Our model does both, which gives us more control over the relevant mantle processes."
More:
https://www.sciencedaily.com/releases/2017/12/171218120327.htm
