Yuqi’s paper titled “Seismotectonic segmentation controlled by magmatic underplating in the central-southern segment of Tanlu fault zone, eastern China” has been accepted for publication in Earth and Planetary Letters.

The paper investigates crustal structure of the Central-South Tianlu fault and concludes that the 1668 Tancheng earthquake (M8.5) occurred in the segment with specific crustal structures.

Here is the abstract of the paper:

Intracontinental earthquakes usually cause severe casualties and property damage, yet their mechanism is still unclear. The TanLu Fault Zone (TLFZ) has been a typical large intracontinental strike-slip fault in eastern China since the Quaternary, which has hosted many large earthquakes (M ≥ 6). Generation of large earthquakes is generally closely related to the heterogeneities on and adjacent to the fault plane, which may result from different composition and inclusions of fluids. In this study, we use the receiver function method to obtain detailed distributions of Poisson’s ratio and crustal thickness in the central-southern segment of the TLFZ, where the M 8.5 TanCheng earthquake occurred in 1668. We found that the distribution of earthquakes is strongly correlated with the crustal structures, both of which exhibit clear segmentation. The strongly damaged zone (with earthquake intensity img 10) of the 1668 TanCheng earthquake and present small-to-moderate earthquakes are generally located above a segment that has shallower Moho and particularly higher Poisson’s ratio. We propose that the high Poisson’s ratio may be caused by intrusive mafic rocks in the ductile lower crust, which plays a role as local stress concentrators and subsequently leads to large intracontinental earthquakes.

陆内地震通常比板块边界地震造成更严重的人员伤亡和财产损失，但其成因机制尚不完全清楚。郯庐断裂带是中国东部最大的陆内走滑断裂带，历史上曾发生过多次大地震，为研究陆内地震成因提供了合适的场所。研究团队采用接收函数方法，获得了郯庐断裂带中南段的高分辨率泊松比和地壳厚度分布，发现地震构造与地壳结构密切相关，并表现出明显的分段特征。本研究的主要发现包括：

  1. 郯庐断裂带中南段地震活动与地壳结构具有相同的分段性。1668年郯城大地震（M 8.5）和现今的高地震活动性均位于莫霍面较深且泊松比较高的区域。
  2. 侵入下地壳的基性岩可能作为局部应力集中体，促使了地震的发生。这为理解陆内地震的成因提供了新的线索。
  3. 郯庐断裂带中南段的地震活动分布可能受到不同程度的岩浆底侵作用影响。