近日,美国阿拉巴马大学Long M. Ho团队报道了东南极洲的上地幔地震。该项研究成果发表在2026年5月28日出版的《科学》杂志上。
板内中源地震发生在深度超过70公里的位置,远低于地壳的脆-韧性转变带,其成因难以用传统板块构造理论来解释。
研究组将深度学习技术应用于区域地震数据,在南极洲下方识别出了板内中源地震。这些地震的发生可以解释为:沿着南极洲东部边缘,由于热驱动的差异性地表抬升,导致岩石圈强度发生突变,从而产生集中的弯曲应力。
该研究结果支持了地球动力学模型的预测,即板内地震活动性强烈依赖于岩石圈-软流圈之间的相互作用。南极冰盖也会影响区域应力状态,凸显了地球各圈层之间复杂的相互作用。先进的地震探测能力(如本研究采用的这种技术)可能揭示出,板内中源地震在全球范围内比目前所认识到的更为普遍。
附:英文原文
Title: Upper-mantle earthquakes beneath East Antarctica
Author: Long M. Ho, José L. Sánchez-Roldán, Samantha E. Hansen, Jacob I. Walter
Issue&Volume: 2026-05-28
Abstract: Intraplate intermediate-depth earthquakes (IDEs) occur at depths >70 kilometers, which is well below the brittleductile 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 lithosphereasthenosphere interactions. The Antarctic ice sheet can also affect regional stress conditions, highlighting the complex interplay between Earth systems. Advanced seismic detection capabilities, such as those used here, could reveal that intraplate IDEs are more common globally than currently recognized.
DOI: aea9895
Source: https://www.science.org/doi/10.1126/science.aea9895
