We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) seismic stations. The seismic events, with local magnitudes (M_L) ranging from 1.1 to 3.5, are predominantly clustered in four geographic regions; the Ellsworth Mountains, Thwaites Glacier, Pine Island Glacier, and Mount Takahe. Eighteen of the events are in the Ellsworth Mountains and can be attributed to a mixture of glacial and tectonic processes. The largest event noted in this study was a mid‐crustal (∼19 km focal depth; M_L 3.5) normal mechanism earthquake beneath Thwaites Glacier. We also located 91 glacial events near the grounding zones of Thwaites Glacier and Pine Island Glacier that are predominantly associated with time periods of significant calving activity. Eight events, likely arising from volcano‐tectonic processes, occurred beneath Mount Takahe. Using Pn travel times from the seismic events, we find laterally variable uppermost mantle structure in central West Antarctica. On average, the Ellsworth Mountains are underlain by a faster mantle lid (V_Pn = ∼8.4 km/s) compared to the Amundsen Sea Embayment region (V_Pn = ∼8.1 km/s). Within the Amundsen Sea Embayment itself, we find mantle lid velocities ranging from ∼8.05 to 8.18 km/s. Laterally heterogeneous uppermost mantle structure, indicative of variable thermal and rheological structure, likely influences both geothermal heat flux and glacial isostatic adjustment spatial patterns and rates within central West Antarctica.

中文翻译：

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南极中西部的地震活动和Pn速度结构

我们使用极地地球观测网（POLENET / ANET）和英国南极网（UKANET）地震台站上记录的数据，找到了117个以前未检测到的地震事件，这些地震事件主要发生在2015年至2017年之间，起源于南极西部中部的冰川，构造和火山爆发。地震事件的局部震级（M _L）范围为1.1至3.5，主要集中在四个地理区域。埃尔斯沃思山脉，Thwaites冰川，Pine Island冰川和Takahe山。其中有18个事件发生在Ellsworth山脉，可以归因于冰川和构造过程的混合。在这项研究中提到的最大事件是中地壳（~19公里，震源深度;中号_大号3.5）Thwaites冰川下的正常机制地震。我们还在Thwaites冰川和Pine Island冰川的着陆区附近发现了91个冰川事件，这些事件主要与大量产犊活动的时间段有关。塔卡河山下发生了八起事件，可能是由于火山构造过程引起的。利用地震事件中的Pn传播时间，我们发现了南极西部中部横向变化的最高地幔结构。平均而言， 相较于阿蒙森海域（V _Pn），埃尔斯沃思山脉的下盖速度更快（V _Pn =〜8.4 km / s）。 =〜8.1 km / s）。在阿蒙森海堤本身内，我们发现地幔盖的速度范围为〜8.05至8.18 km / s。南极中部的横向非均质结构，指示出热学和流变学结构的变化，可能同时影响南极西部中部的地热热通量和冰川等静压调整空间格局和速率。