Wednesday, January 3, 2018

USA, Wyoming: New Explanation for Newberry and Yellowstone Geothermal Heat

There's a new theory for how the Yellowstone National Park supervolcano gets its hotspot (Billings Gazette)

In this depiction the ancient Farallon slab (blue) below the eastern United States sinks and drives the eastward mantle below the western U.S., whereas the Juan de Fuca slab (green) induces a local westward-returning wedge flow. These two opposing flows generate the Yellowstone and Newberry hotspot tracks. (Courtesy Nature Geoscience)
Newly published research contradicts what has been a long-held — although fervently debated — theory about the hotspot underlying the Yellowstone supervolcano.

Geologists at the University of Illinois used seismic waves that travel through the earth after earthquakes and explosions to produce an almost X-ray-like view of what’s going on underground. The information was then fed through a supercomputer to mimic different geologic scenarios that are known to have occurred over the past 20 million years in an attempt to come up with an explanation for the Yellowstone hotspot.

Their conclusion? Yellowstone’s heat is being funneled east from the geologically active Pacific Coast.

Read More.........

Western US volcanism due to intruding oceanic mantle driven by ancient Farallon slabs, Quan Zhou, Lijun Liu & Jiashun Hu. Nature Geoscience 11, 70–76 (2017) doi:10.1038/s41561-017-0035-y