3-D active source tomography around Simeulue Island offshore Sumatra: Thick crustal zone responsible for earthquake segment boundary
3-D active source tomography around Simeulue Island offshore Sumatra: Thick crustal zone responsible for earthquake segment boundary
复制标题
苏门答腊岛近海锡默卢岛周围的 3D 主动源断层扫描：厚地壳带是地震段边界的原因
DOI：
10.1029/2012gl054148
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发表时间：
2013
影响因子：
5.2
通讯作者：
Tang G
中科院分区：
文献类型：
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作者：
Tang G
利用苏门答腊岛俯冲带段边界的地震折射资料，利用初至旅行时层析成像技术建立了详细的3-DP波速度模型，并从深度偏移的多道地震反射剖面中提取了俯冲洋壳顶部的图像。我们提取了由海底地震仪局域网络记录的气枪震源地震数据的P波初至，并对俯冲带的三维速度模型进行了旅行时反演。这一速度模型显示了洋壳和地幔之间的中等速度异常区，这与洋壳顶部的隆起地形有关。我们将这一特征解释为俯冲板块中具有成分和地形变化的增厚地壳带，对上板块结构和2004年和2005年地震破裂的分段提供了初步控制。
We present a detailed 3‐DP‐wave velocity model obtained by first‐arrival travel‐time tomography with seismic refraction data in the segment boundary of the Sumatra subduction zone across Simeulue Island, and an image of the top of the subducted oceanic crust extracted from depth‐migrated multi‐channel seismic reflection profiles. We have pickedP‐wave first arrivals of the air‐gun source seismic data recorded by local networks of ocean‐bottom seismometers, and inverted the travel‐times for a 3‐D velocity model of the subduction zone. This velocity model shows an anomalous zone of intermediate velocities between those of oceanic crust and mantle that is associated with raised topography on the top of the oceanic crust. We interpret this feature as a thickened crustal zone in the subducting plate with compositional and topographic variations, providing a primary control on the upper plate structure and on the segmentation of the 2004 and 2005 earthquake ruptures.