【摘要】 本文对鄂尔多斯块体进行了广泛的研究。根据块体体周边的M—t图划分了三个地震活跃期,由∑E^1/2i-t曲线外推了块体周边织累的应变,据M_S≥4.0 级地震的震级一频度关系求得块体周边的b值为0.42—0.56。 块体周边的强震有成组孕育的特点,在一个周边上发生了M_S≥6.0级的地震后,数年内（一般不超过5年）在块体其它周边上常跟着发生M_S≥6.0级的地震。研究了块体周边M_S≥7.0级地震前的活动图象,发现震前“活动区”和“空白区”可能并存。最后阐述了块体周边地壳应力场的方向,并计算了块体周边的平均滑动速率。更多还原

【Abstract】 In this paper, extensive studies are obtained for the Eerduosi block peripheries. The seismicity of Eerduosi block peripheries is divided into three high seismicity periods according to the M-t map. Accumulated strain of the blockperipheries is deduced from -t diagrams. The b-values obtained fromthe frequencies of Ms≥4.0 earthquakes are in the range ot 0.42-0.56 for the block peripheries.The strong earthquakes occurred in the block peripheries have characteristes of being prepared in group.s. After the Ms≥6.0 earthquake occurred on one side of the peripheries of the block, earthquakes of Ms≥6.0 often occurred sequentially on the other sides of the peripheries within the next several years (generally less than 5 years). Seismicity patterns on the block peripheries before the occurrences of Ms≥7.0 earthquakes are also studied in this paper. It is found that before the Ms≥7.0 earthquakes, the seismically-active regions and seismic gaps can coexist. Finally, the direction of the stress field in the crust under the block peripheries are discussed, and the average slip rates along the block peripheries calculated.更多还原