Seismic tomography of the North Anatolian Fault: New insights into structural heterogeneity along a continental strike‐slip fault
Seismic tomography of the North Anatolian Fault: New insights into structural heterogeneity along a continental strike‐slip fault
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DOI：
10.1002/2017gl072726
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发表时间：
2017-03
影响因子：
5.2
通讯作者：
E. Papaleo;D. Cornwell;N. Rawlinson
中科院分区：
文献类型：
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作者：
E. Papaleo;D. Cornwell;N. Rawlinson
了解岩石圈内大陆走滑断层的结构，对于了解变形发生在哪里以及应变如何随深度局部化是至关重要的。为了改善对大陆主要走滑断裂的下地壳和上地幔结构的约束，我们提供了土耳其北安纳托利亚断裂带(NAFZ)的高分辨率远震层析成像。我们的结果突出表明，在断层的两个分支之间存在一个相对较高的速度体，并且在∼20公里的距离上，NAFZ的速度结构沿走向有显著的变化。我们将这些发现解释为由先前存在的异质性引起的横向可变应变聚焦的证据。在NAFZ下方的地壳和上地幔中观察到的低速度支持了上地幔存在一个狭窄的剪切带，我们将其宽度限制在∼50公里。
Knowledge of the structure of continental strike‐slip faults within the lithosphere is essential to understand where the deformation occurs and how strain localizes with depth. With the aim to improve the constraints on the lower crust and upper mantle structure of a major continental strike‐slip fault, we present a high‐resolution teleseismic tomography of the North Anatolian Fault Zone (NAFZ) in Turkey. Our results highlight the presence of a relatively high velocity body between the two branches of the fault and significant along‐strike variations in the NAFZ velocity structure over distances of ∼20 km. We interpret these findings as evidence of laterally variable strain focussing caused by preexisting heterogeneity. Low velocities observed in the crust and upper mantle beneath the NAFZ support the presence of a narrow shear zone widening in the upper mantle, where we constrain its width to be ∼50 km.