Is the Shanxi rift of northern China extending?
Is the Shanxi rift of northern China extending?
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DOI：
10.1029/2003gl018764
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发表时间：
2003-12
影响因子：
5.2
通讯作者：
Jiankun He;Mian Liu;Yan-xing Li
中科院分区：
文献类型：
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作者：
Jiankun He;Mian Liu;Yan-xing Li
中国北部的山西裂谷以强烈的地震活动为标志，包括许多破坏性的历史地震。地质和地震学证据表明，横跨裂谷的伸展速度为0.5-1.6毫米/年，以前的GPS结果显示伸展速度为4±2毫米/年。我们在这里展示了新汇编的GPS数据，这些数据表明了连贯的地壳运动，并且没有明显的迹象表明跨越裂谷的延伸。我们在一个简单的粘弹性有限元模型中协调了地质观测和GPS结果之间的差异，该模型考虑了地壳形变的时间尺度。GPS速度可以用具有接近弹性的上地壳的模型来拟合，这与主要的地震间变形是一致的。在地壳结构非均质性产生的重力势能的驱动下，预测了地壳粘性蠕变占优势时的地质伸展速率。
The Shanxi rift in northern China is marked by intensive seismicity, including many devastating historic earthquakes. Geological and seismological evidence show 0.5–1.6 mm/yr extension across the rift, and previous GPS results indicated an extension rate of 4 ± 2 mm/yr. We show here newly compiled GPS data that indicate coherent crustal motion and no clear sign of extension across the rift. We reconcile the discrepancy between geological observations and GPS results in a simple viscoelastic finite element model with timescale‐dependent crustal deformation. The GPS velocities can be fit by a model with a near elastic upper crust, consistent with predominantly interseismic deformation. The geological rate of extension is predicted when viscous creep of the crust is dominant, driven by the gravitational potential energy arising from the heterogeneity of crustal structure.