More constraints to determine the seismic structure beneath the Central Andes at 21°S using teleseismic tomography analysis
More constraints to determine the seismic structure beneath the Central Andes at 21°S using teleseismic tomography analysis
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DOI：
10.1016/j.jsames.2007.08.009
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发表时间：
2008-02
影响因子：
1.8
通讯作者：
B. Heit;I. Koulakov;G. Asch;X. Yuan;R. Kind;I. Alcocer-Rodriguez;S. Tawackoli;H. Wilke
中科院分区：
文献类型：
--
作者：
B. Heit;I. Koulakov;G. Asch;X. Yuan;R. Kind;I. Alcocer-Rodriguez;S. Tawackoli;H. Wilke
在安第斯山脉中部地区沿着智利和玻利维亚之间南纬21°的一条600公里长的地震剖面线上部署了一套地震台站，从2002年3月至2004年1月，运行了近两年。在这里，我们提出的P波速度异常的层析反演的结果，在台站记录的地震资料的基础上。通过一系列的综合试验，验证了结果的可靠性.断层图像显示，在西部的配置文件，这是来自前弧冷物质的指示高速。低速异常被检测到的边界之间的前和火山弧的克夫拉达布兰卡地震异常先前描述。这一异常可能与俯冲板块内100km深处的地震群中存在流体有关。一个强大的低速异常下检测到整个高原和东科迪勒拉的一部分，与以前的接收器功能的结果。巴西地盾被认为是负责强烈的高速异常下的安第斯山脉和Subandean地区。
A set of seismological stations was deployed in the Central Andes region along a ∼600km long profile at 21°S between Chile and Bolivia and operated for a period of almost two years, from March 2002 to January 2004. Here we present the results of the tomographic inversion for P-wave velocity anomalies, based on teleseismic data recorded at the stations. The reliability of the results has been checked by a series of synthetic tests. The tomographic images show high-velocities on the west of the profile that are indicative of cold material from the fore-arc. A low-velocity anomaly is detected at the border between the fore- and the volcanic arc where the Quebrada Blanca seismic anomaly was previously described. This anomaly might be related to the presence of fluids that originate at the cluster of earthquakes at a depth of ∼100km in the subducted plate. A strong low-velocity anomaly is detected beneath the entire Altiplano plateau and part of the Eastern Cordillera, in agreement with previous receiver function results. The Brazilian Shield is thought to be responsible for the strong high-velocity anomaly underneath the Interandean and Subandean regions.