基于广义极值理论的潜在地震海啸源震级上限及强震重现水平的估计——以琉球海沟俯冲带为例

Estimation of upper bound earthquake magnitude and return level of strong earthquake for potential seismic tsunami zone based on generalized extreme value theory——A case study of Ryukyu trench subduction zone

以琉球海沟俯冲带作为研究区,将广义极值理论用于估计潜在地震海啸源震级上限,首先分析了琉球海沟俯冲带的地震地质构造特征以及历史地震资料,界定潜在地震海啸源区,然后根据地震活动性特征按时间域进行分割,并提取各时间段发生的极限震级的地震样本,最后通过广义极值分布模型估计了该区域的震级上限值和强震重现水平,并对其进行了不确定性分析。

In this study, we apply generalized extreme value theory to the estimation of upper bound earthquake magnitude and the return level of strong earthquake for the potential seismic tsunami source and choose the Ryukyu trench subduction zone as the case study area. Firstly,we analyze the characteristic of geological structure and historical earthquake data, and delineate the potential earthquake tsunami source region. Then we divide the time domain into intervals according to the seismicity, and extract the upper limit earthquake magnitude samples of each time interval. Finally we establish the generalized extreme value model to estimate the upper bound earthquake magnitude and the return level of strong earthquake, and as well as analyze uncertainty of the estimation results.