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yexuqing木虫之王 (文学泰斗)
太阳系系主任
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Upper-mantle earthquakes beneath East Antarctica
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Upper-mantle earthquakes beneath East Antarctica 东南极洲下方的上地幔地震 ▲ 作者：LONG M. HO, JOSé L. SáNCHEZ-ROLDáN, SAMANTHA E. HANSEN, AND JACOB I. WALTER ▲链接： https://www.science.org/doi/10.1126/science.aea9895 ▲摘要： 板内中源地震（IDEs）发生在深度超过 70 公里的区域，远低于地壳的脆—韧性转变深度，其成因难以用传统板块构造理论解释。研究者将深度学习技术应用于区域地震数据，识别出南极洲下方的板内中源地震。这些地震的发生可以用东南极洲边缘（该处岩石圈强度发生突变）因热驱动差异抬升所产生的集中弯曲应力来解释。 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，凸显了地球各系统之间复杂的相互作用。先进的地震探测能力（如本文所使用的技术）可能揭示出，板内中源地震在全球范围内比目前认识到的更为普遍。 ▲ Abstract： 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. Advanced seismic detection capabilities, such as those used here, could reveal that intraplate IDEs are more common globally than currently recognized. |
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