Utah's Deep Mantle Quake Redefines Where Quakes Can Happen
University of Utah researchers reanalyzed decades of seismic data and confirmed that a 1979 Utah quake originated about 90 kilometers below the surface, revealing a rare continental mantle earthquake (CME) class. Their work, complemented by a 2025 Maeser event, shows these deep quakes occur in the mantle near the Wyoming Craton and Moho, challenging decades of assumptions about where earthquakes can originate beneath continents and informing mantle dynamics and seismic hazard assessment.