Rayleigh-Wave Multipathing along the West Coast of North America
Rayleigh-Wave Multipathing along the West Coast of North America
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DOI：
10.1785/0120040180
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发表时间：
2005-12
影响因子：
3
通讯作者：
C. Ji;S. Tsuboi;D. Komatitsch;J. Tromp
中科院分区：
文献类型：
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作者：
C. Ji;S. Tsuboi;D. Komatitsch;J. Tromp
我们已经创建了一个电影的地表地面运动的2002年11月3日德纳里断层地震的基础上，使用地壳模型CRUST2.0，地幔模型S20 RTS，地形和测深模型ETOPO 5，和有限断层滑动模型的谱元模拟。这部电影的特点是两个不规则的波包，沿着北美板块的西海岸，沿着偏离大圆的路径传播。这些波包是瑞利波，主要周期约为20秒，这也是在南卡利-加利福尼亚地震台网记录的地震图中发现的。这些数据包之一是直达表面波，其组到达时间横向变化，由俄勒冈州海岸的形状决定。另一个波包是由落基山脉下面的横向界面反射的表面波。平行于加拿大海岸的线性反射体将其偏移几百公里可以解释其到达时间，但从合成地震图得出的偏移距离将反射体置于从数据获得的结果东北350公里处，这表明需要更新该地区的地壳和地幔模型。在线资料：2002年德纳里地震的标准化模拟垂直位移动画。
We have created a movie of surface ground motion for the 3 November 2002 Denali fault earthquake based on spectral-element simulations using crustal model CRUST2.0, mantle model S20RTS, topography and bathymetry model ETOPO5, and a finite-fault slip model. The movie features two anomalous wave packets that travel along the west coast of the North American plate following off- great-circle paths. These wave packets are Rayleigh waves with dominant periods around 20 sec, which are also found in seismograms recorded by the Southern Cali- fornia Seismic Network. One of these packets is the direct surface wave, whose group arrival time changes laterally as dictated by the shape of the Oregon coast. The other packet is a surface wave reflected by a lateral interface underneath the Rocky Moun- tains. A linear reflector parallel to the Canadian coast offsetting it by a few hundred kilometers can explain its arrival time, but the offsetting distance derived from the synthetic seismograms puts the reflector 350 km northeast of the result obtained from the data, indicating a need to update the crustal and mantle models in this area. Online material: Animation of normalized simulated vertical displacement for the 2002 Denali earthquake.