【摘要】 2024年1月23日新疆乌什M_S7.1地震是自1992年吉尔吉斯斯坦SuusamyrM_S7.3地震以来发生在天山地震带内的最大地震。主余震初步精定位和第一时间野外调查结果表明，乌什M_S7.1地震的余震带总体走向NE,长约62km,主要分布在盆山交接部位。地震产生了边坡失稳、岩崩、滚石、地裂隙等次生地质灾害，主要集中在沿构造走向微观震中两侧30km范围内。由微观震中向N约7km、向S约13km以外，地质灾害迅速减轻，且山前断层陡坎（F₅）未见任何新鲜的活动迹象。结合中国地震局地质研究所产出的InSAR同震形变场初步结果，判定此次主震的发震断层为一条倾向NW、未错出地表的逆冲断层。在GCMT震中所在的恰勒玛提河，沿西域砾岩背斜南翼发现了总体走向N60°E、长约2km、最大垂直位错约1m的地震地表破裂带。该地表破裂在较老地貌面上基本沿先存断层陡坎发育，总体受一条倾向SE、与主震发震断层倾向相反的逆断裂控制。地表破裂带长2km,规模远小于乌什M_S7.1地震余震带，其是由M_S7.1主震所致还是因M_S5.7余震造成的，以及产生地表破裂的SE倾逆断层与NW倾主震发震断裂之间是何种关系，还需进一步研究。更多还原

【Abstract】 The M_S7.1 earthquake in Wushi,Xinjiang on January 23,2024,represents the largest earthquake in the Tianshan seismic belt since the 1992 Suusamyr M_S7.3 earthquake in Kyrgyzstan.Preliminary precise aftershock localization and initial field investigations indicate an NE-trending aftershock zone with a length of 62km that is concentrated at the mountain-basin transition area.This event produced geological hazards,including slope instability,rockfalls,rolling stones,and ground fissures,primarily within a 30-kilometer radius around the epicenter.The epicenter,located approximately 7 kilometers north of the precise positioning in this study,witnessed a rapid decrease in geological hazards such as collapses,with no discernible fresh activity observed on the steep fault scarp along the mountainfront.Consequently,it is inferred that the causative fault for this main shock may be an NW-dipping reverse fault,with potential rupture not reaching the surface.Moreover,a surface rupture zone with a general trend of N60°E,extending approximately 2kilometers,and displaying a maximum vertical offset of 1m,was identified on the western side of the micro-epicenter at the Qialemati River.This rupture zone predominantly follows the pre-existing fault scarp on higher geomorphic surfaces,indicating that it is not new.Its characteristics are mainly controlled by a southeast-dipping reverse fault,opposite in dip to the causative fault of the main shock.The scale of this 2-kilometer-long surface rupture zone is notably smaller than the aftershock zone of the Wushi M_S7.1 earthquake.Further investigation is warranted to elucidate whether or not the M_S5.7 aftershock and the relationship between the SE-dipping reverse fault responsible for the surface rupture and the NW-dipping causative fault of the main shock produced it.更多还原