Scientists Identify 9 Deep Mantle Quakes Beneath Utah and Wyoming
Updated
Updated · VICE · Jun 2
Scientists Identify 9 Deep Mantle Quakes Beneath Utah and Wyoming
3 articles · Updated · VICE · Jun 2
Summary
At least nine earthquakes beneath Utah and southwest Wyoming originated about 90 kilometers down in Earth’s mantle, leading researchers to define a new class of “continental mantle earthquakes.”
University of Utah scientists reached that conclusion by reanalyzing a magnitude 3.8 Randolph, Utah, quake from 1979 and matching it with similar deep events once considered impossible.
These quakes appear unlike typical earthquakes: they show no foreshocks or aftershocks and occur where mantle temperatures can exceed 700C, where rock is usually too ductile to fracture.
Researchers suspect stress builds over millions of years where flowing mantle material meets a deep lithosphere “keel” in the Wyoming Craton, though the exact physics and maximum possible size remain unknown.