【摘要】 利用层析成像的最新成果,对研究区(28°～39°N,112°～124°E)的中强地震深部构造环境进行了研究,结果表明:(1)研究区中强震位置、地表地质构造和活动构造单元的划分与上地壳速度结构之间存在一定的关联性。M≥6.0地震大多数分布在上地壳高速区与低速区的交接地带或高速区,低速区内的地震活动相对较少;分布在高速区的地震,主要活动在高速区内的速度变异地带。华北平原断块的边界带及其内部是研究区内主要的中强地震活动场所,该断块西、北部的裂陷盆地带在上地壳以间断的大片低速区为特征,在与高速区的交接地带,中强地震呈带状活动,并有活动断裂带的发育。北西向展布的周口-合肥-宣城低速条带分隔大别山、鲁西-安徽高速区,北侧与高速区的交接地带中强地震活动较为活跃,可能是华北、华南两大构造区在深部构造和现代活动构造上的一条重要分界线。(2)霍山-六安地区历史中强地震和近代小震活动频繁与东大别山中部在中地壳发育低速层及存在切穿地壳的两组深断裂有关。(3)安徽的中强地震活动在深部构造上分区特征明显,依据历史地震活动重演和发震构造条件(深部)类比的原则,对安徽未来存在发生5级左右地震的危险区进行了初步判定。更多还原

【Abstract】 By using of a new results of seismic tomography,we studied the deep tectonic backgrounds of moderate-strong earthquake beneath the region of 28°～39°N,112°～124°E.The results demonstrate:(1)There are some relationships between location of moderate-strong earthquake,upper geologic structure,compartmentalization of active structure unit and velocity structure of upper crust in the research area.Most earthquakes(M≥6.0)distributed within transitional zones between high and low velocity area or high velocity area in the upper crust,the earthquakes in low velocity were minority.The earthquakes in high velocity area were mainly occurred in variation belt.The boundary belt and its internal portion of north China plain rupture were the main active sites of moderate-strong earthquake,the basin belt in west and north rupture have characteristics with discontinuous low velocity area.Moderate-strong earthquake activivity like a belt in transitional zones between high and low velocity area.It developed activity rupture.The low velocity belts with north-west distribution in Zhoukou-Hefei-Xuancheng divide high velocity area in Debie Mountain and west Shandong-Anhui.The moderate-strong earthquake activivity in transitional zones between high velocity and north of low velocity belts.It may be the important deep structure and modern activity structure boundary in north China and south China tectonic area.(2)Historical moderate-strong earthquake and small recent earthquakes active in high frequency in the Huoshan-Liuan area.It has the relationship with low velocity layers were developed in middle crust of the eastern Dabie Mountain and two deep rupture cut through crust.(3)The moderate-strong earthquakes in Anhui have an obvious characteristics with areas at the deep structure.According to the principle that historical earthquake can recur and tectonic condition can contrast,we determined the fatalness areas that the MS 5.0 earthquakes in the future.更多还原