Scientists Investigate Strange Rumbling Beneath Utah

Live updates

1. 10h ago

   Scientists Confirm Rare 'Impossible' Earthquake Beneath Utah’s Mantle

   A 1979 earthquake beneath northern Utah, initially dismissed as unlikely, has been confirmed as a real event deep in Earth’s mantle. Researchers now identify it as part of a rare class of 'continental mantle earthquakes' occurring nearly 90 kilometers underground. The discovery challenges long-held assumptions about seismic activity and could reshape hazard predictions. Ongoing analysis continues to puzzle scientists about the region’s deep seismic behavior.

   What's confirmed:

   • A mysterious earthquake detected beneath northern Utah in 1979 occurred nearly 90 kilometers underground, far deeper than previously thought possible under continental crust.
   • The event belongs to a rare category called 'continental mantle earthquakes,' where rock breaks suddenly deep in Earth’s upper mantle instead of slowly flowing.
   • Reanalysis of decades-old seismic data by University of Utah researchers identified this class of deep earthquakes, contradicting earlier assumptions about their existence.
   • The discovery suggests seismic activity can occur deeper than standard models predict, potentially altering how scientists assess earthquake hazards.
   • The Wyoming Craton region, where the quake occurred, continues to exhibit unusual deep rumbling that has puzzled researchers since 1979.

   Still unconfirmed:

   • A hidden deep-Earth system may transform disaster prediction, though no specific mechanisms or timelines have been confirmed.
   • The 1979 Utah earthquake was initially dismissed as an anomaly or measurement error before recent reanalysis.
   • Ongoing rumbling beneath Utah could signal broader geological shifts, but no direct evidence links it to imminent seismic risks.
   confidence 92%