近日，中国科学院青藏高原研究所李鸿儒团队研究了东喜马拉雅下印度板块的低角度俯冲和大逆冲构造。这一研究成果于2025年10月28日发表在《国家科学评论》杂志上。

东喜马拉雅代表着活跃的洲际辐合和构造走滑运动。它经常发生大地震，摧毁数百万人的人口中心。然而，广泛的走滑运动和板块辐合变形是如何导致频繁地震的，目前还没有公认的解释。

研究组利用他们最近在喜马拉雅东部部署的宽带地震阵列的新数据来确定区域应力场和关于会聚板块的详细结构信息。震源机制得到的应力场以南北水平压缩为主。从南到北横跨喜马拉雅东部，已确定的印度红顶呈现出红顶-地幔边界Moho的低角度俯冲，以及被称为喜马拉雅主红顶（MHT）的板块界面的平斜几何形状。研究组认为，东喜马拉雅下的特大地震和广阔山脉的隆起可以用主要的南北挤压和印度板块的温和下地壳运动来解释。

附：英文原文

Title: Low-angle subduction of the Indian plate and megathrust geometry below the eastern Himalaya

Author: Bai, Ling, Li, Hongru, Chen, Zhiwen, Zhan, Huili, Li, Guohui, Mori, James, Ding, Lin

Issue&Volume: 2025-10-28

Abstract: The eastern Himalaya represents active intercontinental convergence and tectonic strike-slip extrusion. It frequently produces large earthquakes that devastate population centers for millions of people. However, there is no accepted explanation for how the widespread strike-slip motion and plate convergence deformation cause the frequent earthquakes. Here, we use new data from our recently deployed broadband seismic array in the eastern Himalaya to determine the regional stress field and detailed structural information about the converging plates. The stress field obtained from the earthquake focal mechanisms shows dominant north-south horizontal compression. Across the eastern Himalaya from south to north, the identified Indian crust exhibits low-angle subduction of the crust-mantle boundary Moho and flat-ramp geometry of the plate interface termed as the Main Himalayan Thrust (MHT). We suggest that the generation of megathrust earthquakes and the uplift of the broad mountains beneath the eastern Himalaya can be explained by the dominant north-south compression and a gentle underthrusting of the Indian plate.

DOI: 10.1093/nsr/nwaf460

Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf460/8305090searchresult=1