通过垂直地震剖面探测，深入了解帕克菲尔德的圣安德烈亚斯断层。

A look inside the San Andreas Fault at Parkfield through vertical seismic profiling.

作者信息

Chavarria J Andres, Malin Peter, Catchings Rufus D, Shalev Eylon

机构信息

Division of Earth and Ocean Sciences, Nicholas School of Environment and Earth Sciences, Duke University, Box 90227, Durham, NC 27708, USA.

出版信息

Science. 2003 Dec 5;302(5651):1746-8. doi: 10.1126/science.1090711.

DOI:10.1126/science.1090711

PMID:14657494

Abstract

The San Andreas Fault Observatory at Depth pilot hole is located on the southwestern side of the Parkfield San Andreas fault. This observatory includes a vertical seismic profiling (VSP) array. VSP seismograms from nearby microearthquakes contain signals between the P and S waves. These signals may be P and S waves scattered by the local geologic structure. The collected scattering points form planar surfaces that we interpret as the San Andreas fault and four other secondary faults. The scattering process includes conversions between P and S waves, the strengths of which suggest large contrasts in material properties, possibly indicating the presence of cracks or fluids.

摘要

圣安德烈亚斯断层深部观测站先导孔位于帕克菲尔德圣安德烈亚斯断层的西南侧。该观测站包括一个垂直地震剖面（VSP）阵列。来自附近微地震的VSP地震图在P波和S波之间包含信号。这些信号可能是由当地地质结构散射的P波和S波。收集到的散射点形成平面，我们将其解释为圣安德烈亚斯断层和其他四条次生断层。散射过程包括P波和S波之间的转换，其强度表明材料属性存在很大差异，可能表明存在裂缝或流体。