Utah’s Hidden Mantle Quakes Signal a New Deep‑Earth Tremor Class
Researchers have identified a new class of deep, mantle-origin earthquakes in Utah—bursts that occur far below the surface, often with little or no felt shaking—starting from the 1979 Randolph event. By linking several deep events (nine documented cases and a 2025 Utah quake), scientists suggest these quakes nucleate at great depths near the Wyoming Craton, behaving like high‑temperature, viscous molten material. While surface damage is typically low, understanding these mantle quakes is crucial for evaluating seismic hazard and limits of potential magnitudes.
