强震震级预测中凹凸体识别与级联破裂相关研究综述

Review on the Research of Asperity Identification and Cascading Rupture in Forecasting of Earthquake Magnitude

强震震级预测在地震预测领域具有重要的科学意义,同时对防震减灾工作也发挥着重要的现实作用。本文基于国内外相关文献,分析强震震级预测中凹凸体识别与级联破裂等关键问题。通常,地震的发生与凹凸体破坏有关,而对凹凸体的识别,主要可以从震源区介质性质、中小地震活动、断层运动状态、应力状态、摩擦属性等方面开展综合分析。级联破裂的发生会提升地震震级,增加地震灾害风险,断层面曲率、产状变化、阶跃距离等断层几何性质,以及断层面摩擦性质、相邻断层段孕震层宽度变化、断层面应力分布、浅层低速区等断层及周围介质的物理性质控制其发生概率。相关模型、参数的研究有赖于密集观测和断层探察等基础性工作,数值模拟和反演等技术应用以及多学科的综合,希望本文可以为中国重点断层段的强震震级预测工作提供参考。

The magnitude forecasting of strong earthquakes is of great scientific significance,and also plays an important role in the actual work of earthquake prevention and disaster reduction.Based on relevant research progress at home and abroad,this paper focuses on the identification of asperities and cascading ruptures in magnitude forecasting of strong earthquakes.The occurrence of earthquakes usually relates to the destruction of asperities.For the identification of asperities,comprehensive analysis can be carried out mainly from the aspects of the media nature in the seismogenic zone,small-medium seismicity,fault motion state,stress state,friction attribute,etc.The occurrence of cascading ruptures will increase the magnitude of earthquakes and the risk of earthquake disasters.The factors controlling its probability mainly include the geometric properties of faults,such as fault surface curvature,geometry change,step distance,as well as the physical properties of fault and surrounding media,such as the friction properties of fault surfaces,changes in the width of seismogenic layer in adjacent fault segments,stress distribution of fault surfaces and shallow low-velocity fault zones.The research of relevant models and parameters depends on the development of intensive observation,fault exploration and other basic work,the application of numerical simulation,inversion and other technologies,and the integration of multiple disciplines.It is hoped that this paper can provide a reference for the forecasting of strong earthquake magnitude in key fault sections of the Chinese Mainland.