【摘要】 基于1998年以来的中国大陆流动重力网观测数据,分析2008年3月新疆于田7.3级地震前区域重力场动态变化的演化特征。结果表明:区域重力场动态演化图像反映了该地震孕育的中长期(2～10年)基本信息;该地震孕育时的显著重力标志为持续多年的正重力变化(上升)和较大规模的重力变化梯级带,前者有利于地震能量的不断积累,后者有利于地震破裂的发生;该地震孕育过程中相关重力场变化呈增大-加速增大-减速增大的过程,与1976年唐山7.8级地震具类似特征;与该地震有关的多年(8年)最大累积重力变化达200×10-8ms-2。更多还原

【Abstract】 On the basis of the data and results of the repeated gravity observation network in Chinese mainland since 1998,the evolution characteristics of dynamic gravity field changes in the seismogenic region before Yutian Ms7.3 earthquake in Mar,2008 has been analyzed and summarized.The dynamic evolution images of regional gravity field reflects the middle-long term(two to ten years)essential information during the earthquake preparation.The notable gravity symbols of the earthquake preparation are positive gravity change(rise)lasted for many years and relatively large-scale gradient zone of gravity change that the former is in favor of continuous accumulation of seismic energy and the latter makes for occurrence of seismic rupture.The related gravity change during the process of the earthquake preparation have the characteristics:increase-accelerated increase-decelerated increas which is similar to that of Tangshan Ms7.8 earthquake in 1976.The maximum accumulative gravity change related to the earthquake can reach 200×10-8ms-2.更多还原