Scientists just mapped mysterious earthquakes deep inside Earth
Science Daily
February 20, 2026
AI-Generated Deep Dive Summary
Scientists at Stanford University have created the first global map of rare earthquakes that occur deep within Earth's mantle, rather than its crust. These mysterious quakes, which are extremely difficult to detect and confirm, have been revealed through a groundbreaking method that distinguishes them based on seismic wave patterns. The research, published in *Science*, identifies significant clusters of these deep tremors in regions like the Himalayas and near the Bering Strait. Understanding these rare events could provide critical insights into earthquake formation and the internal structure of our planet.
Until now, detecting mantle earthquakes has been a major challenge due to their depth and limited data. These quakes occur hundreds of miles below the Earth's surface, far from the crust where most seismic activity is recorded. While they are too deep to cause significant shaking or damage, they offer valuable clues about the processes occurring in the upper mantle, which play a role in volcanic activity and tectonic movements. The study highlights that these earthquakes tend to cluster in specific areas, such as beneath the Himalayas and near the Bering Strait, suggesting a connection to large-scale geological features.
The researchers developed a novel technique to identify mantle earthquakes by analyzing differences in seismic wave patterns. By comparing two types of waves—Sn (surface) waves and Lg (crustal) waves—they were able to determine whether an earthquake originated in the crust or the mantle. This breakthrough has allowed them to pinpoint hundreds of previously undetected deep quakes worldwide, providing a clearer picture of their global distribution and frequency.
The findings have important implications for earthquake science. While these deep earthquakes are rare, studying them could help scientists better understand the mechanisms behind more common, shallow earthquakes that pose significant hazards. The research also sheds light on the Moho boundary—the dividing line between the crust and the mantle—and how stress is released in Earth's interior. This knowledge could ultimately improve our understanding of earthquake origins and contribute to more accurate hazard assessments.
By revealing the hidden world of deep earthquakes, this study opens new
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Originally published on Science Daily on 2/20/2026