The branching crack model for earthquakes was developed by Vere-Jones and Kagan in the 1970s and the 1980s, respectively. With some simple and rational assumptions, its simulation results explain the Gutenberg-Richter magnitude-frequency relationship and the Omori-Utsu aftershock decay formula. By introducing the concept of the critical zone, this model can be connected with the asperity model, the barrier model, and the nucleation model through a parameter – criticality. Particularly, the size of the critical zone determines the maximum magnitude of potential earthquakes and the source of their anomalies. The key to earthquake forecasting is to determine whether the concerned area is in a critical state and how large the critical zone is. We discuss what kinds of anomalies are meaningful as candidates of earthquake precursors. Finally, we outline modelling strategies for earthquake precursors with low probability gains that are due to the inherent randomness of earthquake source processes.

Vere-Jones和Kagan分别在1970年代和1980年代开发了地震分支裂缝模型。通过一些简单合理的假设，其仿真结果解释了古腾堡-里希特量频关系和大森-宇津余震衰减公式。通过引入临界区的概念，该模型可以通过参数-临界度与粗糙模型，势垒模型和成核模型联系起来。特别是，关键区域的大小决定了潜在地震的最大震级及其异常源。地震预报的关键是确定相关区域是否处于临界状态以及临界区域有多大。我们讨论什么样的异常是地震前兆的候选者有意义。最后，