The 2010 Maule, Chile earthquake: Downdip rupture limit revealed by space geodesy
The 2010 Maule, Chile earthquake: Downdip rupture limit revealed by space geodesy
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DOI：
10.1029/2010gl045805
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发表时间：
2010-12
影响因子：
5.2
通讯作者：
X. Tong;D. Sandwell;K. Luttrell;B. Brooks;M. Bevis;M. Shimada;J. Foster;R. Smalley;Héctor Parra;Juan Carlos Báez Soto;M. Blanco;E. Kendrick;J. Genrich;D. Caccamise
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文献类型：
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作者：
X. Tong;D. Sandwell;K. Luttrell;B. Brooks;M. Bevis;M. Shimada;J. Foster;R. Smalley;Héctor Parra;Juan Carlos Báez Soto;M. Blanco;E. Kendrick;J. Genrich;D. Caccamise
ALOS卫星的雷达干涉测量法捕捉到了与2010年智利马乌莱8.8级地震有关的同震地面变形。ALOS干涉图显示，在距离海沟轴150公里处，条纹图案有一个急剧的过渡，这是Maule地震下倾破裂极限的特征。基于上升和下降ALOS干涉图和13个近场三分量GPS测量的弹性位错模型显示，同震滑动从18 km深度的最大值17 m（沿着走向平均值为6.5 m）或多或少线性减小到43-48 km深度的接近零，定量地指示了孕震区的下倾极限。滑动下降到接近零的深度似乎是在俯冲板块与大陆莫霍面的交叉点。我们的模型还表明，同震滑动消失的深度几乎是均匀的沿着走向的破裂长度为1600公里。平均同震滑动矢量和震间速度矢量不平行，这可以解释为走滑力矩释放的不足。
Radar interferometry from the ALOS satellite captured the coseismic ground deformation associated with the 2010 Mw 8.8 Maule, Chile earthquake. The ALOS interferograms reveal a sharp transition in fringe pattern at ∼150 km from the trench axis that is diagnostic of the downdip rupture limit of the Maule earthquake. An elastic dislocation model based on ascending and descending ALOS interferograms and 13 near‐field 3‐component GPS measurements reveals that the coseismic slip decreases more or less linearly from a maximum of 17 m (along‐strike average of 6.5 m) at 18 km depth to near zero at 43–48 km depth, quantitatively indicating the downdip limit of the seismogenic zone. The depth at which slip drops to near zero appears to be at the intersection of the subducting plate with the continental Moho. Our model also suggests that the depth where coseismic slip vanishes is nearly uniform along the strike direction for a rupture length of ∼600 km. The average coseismic slip vector and the interseismic velocity vector are not parallel, which can be interpreted as a deficit in strike‐slip moment release.