GNSS在断层形变研究中的应用

Application of GNSS for Fault Deformation Studies

大地震多发生在主要活动断裂带及其附近,因此断层形变的监测与研究非常重要。多年来采用跨断层短水准、短基线、跨断裂带综合观测剖面等手段监测断层活动,进而研究断层活动与变形规律。GNSS多用于大面积地壳水平运动场和主要地块活动与变形的研究,随着GNSS数据的积累和应用研究的深入,已有学者用GNSS从不同角度开展断层形变的监测与研究。本文介绍和论述了GNSS在断层形变研究中已有的部分应用和新的探索,主要介绍以下几个方面:①GNSS用于断层走滑活动的监测与研究;②GNSS用于断层垂直活动的监测与研究;③通过研究断层两边地块变形规律并建立应变模型,可分别依据各自模型推测断层的活动与形变,将推测结果与跨断层观测到的实际情况进行研究与比较。研究分析认为,由块体推测的变形与实测变形差异越大,说明块体相互作用越强烈。这可能对强地震地点预测、地震危险性判定及地震趋势预测均有重要意义。

Great earthquakes often occur along active fault belts or near by, thus, the mo- nitoring and researches on fault deformation is quite important. Short leveling, short base- line, and integrated monitoring across fault belts etc. have been used to monitor fault ac- tivities for many years. GNSS data are mainly used to study horizontal movements in large areas and crust block activity. In this paper, some applicationsand new explorations of GNSS for researches on fault deformation are introduced and discussed as follows. （1） Monitoring and study on horizontal sliding of fault with GNSS~ （2） Monitoring and study on vertical movement of fault with GNSS~ （3） By studying the orderliness of crust block deformation on both sides of the fault and setting up models of blockmovement and strain, the fault＇s deformation can be deduced from the models, and then the comparison between the deduced deformation and that monitored directly across faults can be done. Our study shows that the larger the differences of deformation between them, the stronger theaction has between two blocks. This will be very important for prediction of earthquake location and seismic risk estimation.