Deep-Earth Quakes Detected Across Continents, Redefining Earth's Interior
A new global study maps mantle earthquakes—deep quakes originating below the Moho—and shows they occur worldwide, not just in special regions. These deep quakes can be found from the Alps to the Himalayas, East Africa, the western United States, and even the Bering Sea, suggesting mantle earthquakes are more widespread than previously thought. The researchers used a wave-analysis method to distinguish crust-origin quakes from mantle ones and focused on non-subduction regions, highlighting potential links to continental collision and rifting; most mantle quakes are too deep to be felt at the surface (depths around 35 km or more).