关键词: 活动断层, 地震危险性, 地震, 哈尔滨市

Abstract: In the target area of active fault surveying around Harbin City,the latest rupturing ages of the main faults are all early or middle Pleistocene,and there are no evidences to indicate that rupture has occurred on these faults since late Pleistocene.By synthetical analysis of technical route of earthquake risk assessment of urban active fault,seismic environment and division of potential seismic source zone in research area around Harbin City,and activity characteristics of the main faults in target area,the maximum magnitude of probable future earthquake on these main faults are forecasted in this paper.And then probabilities of middle-strong earthquake occurring in the next 100 years are calculated for both the whole target area and its three single faults according to the two scales of Xin'an-Dongmeng active block and research area on the basis of adjusting properly the probability technique of earthquake risk analysis for engineering seismology.In conclusion,the probable future maximum magnitude on the main faults in target area are all M_S 5.5,but there is bally low probability of damaging earthquake(M_S>4)occurring on them.No doubt,there are still a few uncertainty and unreliability to these results because of the hypothesis for calculation and deficient samples for statistic.However,in terms of current level,the technique of earthquake risk assessment in this paper is more suitable to use for such still areas as Harbin,where the tectonic activity is quite weak since late Quaternary.And furthermore,it can provide at a certain extent tutor or reference for surveying and prospecting of active fault in other cities.

Key words: active fault, earthquake risk, earthquake, Harbin City