Non‐double‐couple earthquake mechanisms at the Geysers Geothermal Area, California
Non‐double‐couple earthquake mechanisms at the Geysers Geothermal Area, California
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DOI：
10.1029/96gl00590
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发表时间：
1996-04
影响因子：
5.2
通讯作者：
A. Ross;G. Foulger;B. Julian
中科院分区：
文献类型：
--
作者：
A. Ross;G. Foulger;B. Julian
反转P-和S-波极性和P：SH振幅比，使用线性规划方法表明，约20%的地震在间歇泉地热区有显着的非双耦合震源机制，爆炸体积分量高达33%的地震时刻。这一结论与早期的研究形成了鲜明对比，早期的研究以双夫妇的方式解释数据。非双力偶机制与剪切-张性联合断裂作用一致，可能是工业注水引起的。内爆机制，这可能是预期的，因为快速抽汽，还没有发现。重要的补偿线性矢量偶极（CLVD）组件在某些机制可能表明快速流体流动伴随裂纹张开。
Inverting P- and S-wave polarities and P :SH amplitude ratios using linear programming methods suggests that about 20% of earthquakes at The Geysers geothermal area have significantly non-double-couple focal mechanisms, with explosive volumetric components as large as 33% of the seismic moment. This conclusion contrasts with those of earlier studies, which interpreted data in terms of double couples. The non-double-couple mechanisms are consistent with combined shear and tensile faulting, possibly caused by industrial water injection. Implosive mechanisms, which might be expected because of rapid steam withdrawal, have not been found. Significant compensated-linear-vector-dipole (CLVD) components in some mechanisms may indicate rapid fluid flow accompanying crack opening.