Finite Fault Database (ANSS ComCat)

A Finite Fault is a modeled representation of the spatial extent, amplitude and duration of fault rupture (slip) of an earthquake, and is generated via the inversion of teleseismic body waveforms and long period surface waves. It may indicate that a location of major fault-slip and source of seismic energy has occurred at a significant distance from the earthquake epicenter, which is the location on the fault where the earthquake rupture nucleated. For many earthquakes, the preferred model represents the distribution of slip on one of the two alternative fault-planes that are implied by the earthquake moment-tensor. For some earthquakes, the seismographic data are fit equally well by models involving slip on either one of the two alternative fault-planes that are implied by the earthquake moment-tensor, and both models are represented. For yet other earthquakes, the preferred finite-fault model represents the distribution of slip on a plane or multiple planar surfaces whose orientations are adjusted from one of the moment-tensor fault-planes. The ANSS Comprehensive Catalog (ComCat) contains Finite Fault models for many earthquakes. Use the Advanced Options portion of the search page in the Online Link, and then select Finite Fault from the Product Type sub-menu to access the database.

有限震源模型（Finite Fault）是对地震断层破裂（滑移）的空间范围、振幅与持续时间的建模表征，其通过反演远震体波（teleseismic body waveforms）与长周期面波（long period surface waves）生成。该模型可表征在距地震震中——即断层上地震破裂起始的位置——显著距离处发生的主断层滑移位置与地震能量源。针对多数地震，优选模型对应地震矩张量（moment-tensor）所暗示的两个备选断层面之一的滑移分布。对于部分地震，采用两个备选断层面任一的滑移模型均可很好地拟合地震观测数据，因此两类模型均会被收录。另有部分地震，其优选有限震源模型表征的是从矩张量断层面之一调整得到方位的单个或多个平面面上的滑移分布。美国国家地震监测系统综合目录（ANSS Comprehensive Catalog, ComCat）收录了大量地震的有限震源模型。可通过在线链接搜索页面的高级选项模块，从产品类型子菜单中选择Finite Fault以访问该数据集。