Analysis of Unlocking Process of Concave-convex Bodies in Wenchuan Earthquake Sequence Based on B-value Tomography
DOI:
https://doi.org/10.54097/basdb791Keywords:
Wenchuan earthquake sequence, B value, High value anomalyAbstract
B-value mapping seems to have an abnormally low value before the main earthquake. When this gridding technique is applied to Wenchuan earthquake, Lushan earthquake and Jiuzhaigou earthquake of the Wenchuan earthquake sequence of Longmenshan fault, the characteristics of low B-value before the earthquake are not found. On the contrary, the anomalies of high B-value above 20km before Lushan earthquake and Jiuzhaigou earthquake are obvious in the shallow crust. Although Wenchuan earthquake had a strong shadow on Jiuzhaigou earthquake, there was an obvious area where B value increased between the two faults. After Jiuzhaigou earthquake, the area increased to 0.78. Combined with the Lushan earthquake, there is a funnel-shaped high-value area below 25km depth. The reasonable explanation is that the unlocking of deep stress and shallow seismic activity jointly promoted the Jiuzhaigou earthquake.
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