东南极洲上地幔地震

Long M. Ho1*, José L. Sánchez-Roldán2, Samantha E. Hansen1, Jacob I. Walter3 Intraplate intermediate-depth earthquakes (IDEs) occur at depths >70 kilometers, which is well below the brittle‒ductile transition in Earth’s crust, and their origins are difficult to reconcile with traditional plate tectonics. We applied a deep- learning technique to regional seismic data and identified intraplate IDEs beneath antarctica. Their occurrence can be explained by concentrated bending stresses resulting from variable, thermally driven uplift along the edge of East antarctica, where there is an abrupt change in lithospheric strength. Our results support geodynamic model predictions that intraplate seismicity strongly depends on lithosphere‒ asthenosphere interactions. The antarctic ice sheet can also affect regional stress conditions, highlighting the complex interplay between Earth systems. …