中强地震空间分布“X”图像及其含义

Implication of “X” distribution of moderate earthquake

基于西太平洋板块向欧亚大陆板块下俯冲产生的推挤,造成黑龙江亚板块地下的地幔物质上涌,使其上覆岩石圈受到垂直方向上涌力的作用。通过分析"X"节理的形成、与断层的关系、火山群"X"型断裂构造的特点,对黑龙江亚板块1999年以来中强地震空间分布进行研究,呈网格化特征分布。根据构造类比法和历史地震比拟法,网格化交汇处缺震区未来几年或更长时间存在发生中强地震的背景,即内蒙古扎兰屯,通辽和黑龙江五大连池,绥化历史老震区;尤其是2008年6月10日内蒙古扎兰屯附近(阿荣旗境内)发生M 5.2地震后该地区可能再次成为未来地震的危险区。本文研究结果对区域地震危险区的判定有借鉴意义。

Under the compress caused by the subduction of west Pacific-oceanic plate into Eurasia Plate, the mantle material beneath Heilongjiang subplate spew up and drive the overlying lithosphere uplift vertically. After the analysis on the formation of ＂X＂ joint and its relations with faults and on the characteristics of ＂X＂ joint in volcano, the distribution of moderate earthquakes with gridding character in this area since 1999 are studied. With the structure a- nalogy method and historical analogy method, the background of moderate earthquake risk is found in the seismic gap of gridding distribution, namely the older seismic activity area at Zhalantun or Tongliao in Inner Mongolia and Wudalianchi or Suihua in Heilongjiang, in the further of several years or longer time. Especially, the area round Zhalantun in Inner Mon- golia will become an earthquake danger area again in the further after the M 5.2 earthquake on June 10, 2008. This result will be useful for the seismic danger area prediction.