The seismic coupling of subduction zones revisited
The seismic coupling of subduction zones revisited
复制标题
DOI：
10.1029/2011jb009003
复制
发表时间：
2012-04
影响因子：
--
通讯作者：
C. Scholz;J. Campos
中科院分区：
文献类型：
--
作者：
C. Scholz;J. Campos
[1]世界上许多俯冲带的地震耦合的性质已经被重新评估。总结了在地震间隔期间由GPS测量上板块变形获得的地震耦合的大地测量估计。我们将这些结果与从地震学数据中获得的地震耦合的新估计进行了比较。结果表明，除了一些显著的例外，这两种方法的一致性在10%以内。与20-30年前相比，地震学的估计已经有了很大的改进，因为大量的古地震学数据大大延长了大俯冲地震的时间记录，而且在这期间发生了异常数量的大地震和巨型地震，填补了地震记录中一些最关键的空白。除少数明显的例外情况外，这些数据也支持地震耦合的摩擦不稳定理论，特别是Scholz和Campos（1995）对该理论的检验。总的来说，结果支持他们的预测，高耦合发生俯冲带受到高的正常力与切换到低耦合发生相当突然的正常力下降到临界值以下。个别俯冲带内的耦合也有相当大的变化。地震凹凸体与高耦合区域相关，因此具有持久性的表面，但由于地震通量积累相位的差异，大地震的破裂带和凹凸体分布在地震周期之间可能有很大差异。
[1] The nature of seismic coupling for many of the world's subduction zones has been reevaluated. Geodetic estimates of seismic coupling obtained from GPS measurements of upper plate deformation during the interseismic period are summarized. We compared those with new estimates of seismic coupling obtained from seismological data. The results show that with a few notable exceptions the two methods agree to within about 10%. The seismological estimates have been greatly improved over those made 20–30 years ago because of an abundance of paleoseismological data that greatly extend the temporal record of great subduction earthquakes and by the occurrence, in the intervening years, of an unusual number of great and giant earthquakes that have filled in some of the most critical holes in the seismic record. The data also, again with a few notable exceptions, support the frictional instability theory of seismic coupling, and in particular, the test of that theory made by Scholz and Campos (1995). Overall, the results support their prediction that high coupling occurs for subduction zones subjected to high normal forces with a switch to low coupling occurring fairly abruptly as the normal force decreases below a critical value. There is also considerable variation of coupling within individual subduction zones. Earthquake asperities correlate with areas of high coupling and hence have a semblance of permanence, but the rupture zones and asperity distributions of great earthquakes may differ greatly between seismic cycles because of differences in the phase of seismic flux accumulation.