基于全波形反演的中东地壳与上地幔模型
Crustal and upper mantle model of the Middle East based on full-waveform inversion
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中文总结 AI 辅助
该研究基于全波形反演框架，利用大量地震数据和台站信息，经多次迭代开发出中东地区新层析成像模型MEAD-M20，为地震波模拟提供自洽模型，揭示了该地区重要地球动力学和构造特征。
中文摘要 AI 辅助
我们展示了MEAD-M20，这是一个中东及其周边地区（包括安纳托利亚、伊朗和高加索地区）的新层析成像模型。该模型基于全波形反演框架，经20次迭代，利用EarthScope和区域网络的永久和临时台站的广泛数据集，通过3D波场模拟和伴随方法开发而成。从全球FWI模型GLAD-M25开始，在60°x 60°区域网格上，对1215个台站记录的210次区域地震进行反演，得到上地幔具有横向各向同性的P波和S波模型。前12次迭代结合多窗旅行时测量，之后使用精细地壳网格，逐步降低最小面波周期。MEAD-M20为地震波模拟提供了自洽的P波和S波模型，对复杂地区地震定位、震源参数估计和地震危险性评估至关重要。它揭示了几个重要的地球动力学和构造特征，包括阿拉伯板块、约旦和黎凡特下方的地幔柱，以及东安纳托利亚下方特提斯洋的残余等。
英文摘要
We present MEAD-M20, a new tomographic model of the Middle East and its surrounding regions, including Anatolia, Iran, and the Caucasus. The model is developed within a full-waveform inversion framework, based on 3D wavefield simulations and the adjoint method, after 20 iterations, utilizing an extensive dataset from permanent and temporary stations available from EarthScope and regional networks. Starting from the global FWI model GLAD-M25 on a 60°x 60° regional mesh, we invert 210 regional earthquakes recorded by 1,215 stations to obtain the P- and S-wave model with transverse isotropy in the upper mantle. For the first 12 iterations, we combine multitaper traveltime measurements of 15-50 s body waves and 50-100 s body and surface waves on three components. We use a refined crustal mesh to better sample the crust after the 12th iteration and gradually decrease the minimum surface-wave period to 30 s. MEAD-M20 provides a self-consistent P- and S-wave model ready for seismic wave simulations, which is essential for accurate earthquake location, source parameter estimation, and seismic hazard assessment in the geologically and tectonically complex region. MEAD-M20 reveals several important geodynamical and tectonic features, including local mantle plumes beneath the Arabian Plate, Jordan, and the Levant, characterized by low-velocity anomalies and likely associated with volcanism in the Harrats, Jordan, and the Karacadag regions. In addition to the active subduction and rifting in the area, the model clearly identifies remnants of the Tethys Ocean beneath Eastern Anatolia, which become progressively shallower toward the Makran region in the south, consistent with the subduction history along the Bitlis-Zagros suture zone. We also observe lithospheric-scale low-velocity anomalies associated with the North and East Anatolian faults, extending to depths of approximately 200 km.
