日本MW 9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义探讨

为了探讨日本M_W 9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义，对华北和东北地区进行原位现今地应力绝对测量与实时监测、GPS测量，结果表明：日本大地震在山东半岛、华北北部地区和东北地区所诱发同震位移引起的张性效应调整周期分别约为6个月(即调整结束时间大约在2011年9月)、15个月(即调整结束时间大约在2012年6月)和26个月(即调整结束时间大约在2013年5月)，张性效应调整周期与同震位移大小成正比。在这种调整过程中，往往表现出区域现今构造应力作用方式和构造应力场转换，并可能伴随重大地质事件(如地震等)的发生。2012年5月28日和29日、6月18日、8月26日及2013年1月11日在唐山及其周围地区分别发生的4.8级、3.2级、4.0级、3.3级和3.0级地震与华北北部地区构造应力作用方式和构造应力场转换有关，而2013年10月31日以来在吉林省松原市发生的地震群应与东北地区构造应力作用方式和构造应力场转换有关，而非一个大地震前的小震群。

Present tectonic stress adjustment process before and after Japan Mw 9.0 earthquake in North and Northeast China and its research significance

In order to discuss present tectonic stress adjustment process before and after Japan MW 9.0 earthquake in North and Northeast China and its research significance, the measurement of present in situ absolute crustal stress state (including magnitude and orientation) and the real time monitoring of crustal stress values and GPS measuring in North and Northeast China were carried out. The research results show that the adjusting periods of the tensile effect triggered by Japan earthquake coseismic displacement in Shandong peninsula, north region of North China and Northeast China are about 6 months (the adjustment ended about in September 2011), 15 months (the adjustment ended about in June 2012) and 26 months (the adjustment ended about in May 2013), respectively, and that the adjusting cycle of the tensile effect is proportional to the size of coseismic displacement. In this adjustment process, the conversion of the regional tectonic stress action way and tectonic stress field may have happened, which may cause the major geological events (such as earthquakes and so on). The earthquakes, such as MS 4.8 on May 28, 2012, MS 3.2 on May 29, 2012, MS 4.0 on June 18, 2012, MS 3.3 on August 26, 2012, and MS 3.0 on January 11, 2013, in Tangshan and its around region, may be triggered by the conversion in the northern part of North China, and the earthquake swarm in Songyuan city in Jilin Province since October 31, 2013 may be caused by the conversion in Northeast China, rather than small earthquakes before a strong earthquake.