CAJ | 학술논문

自1975年以来，海城附近发生具有一定规模和强度的震群（ML≥4．0；震次≥100次）有：1975年2月4日海城7．3级、1999年11月29日岫岩5．4级、2008年11月14日海城Ml4．8和2012年2月2日盖州Ml4．8震群，这4个震群发生前地震活动背景怎样，是否存在着某种共同的特点？对这4个震群进行对比研究发现：震前1年该区出现小震群活动，ML≥3．0地震条带、地震活动水平明显增强，连续发生多次ML≥4．0地震，ML≥4．0地震震源机制高度一致，且震中最近台站记录P波初动符号出现明显的一致性等变化，可视为地震异常。及时捕捉中强地震前异常，对于地震活动趋势判断起到至关重要的作用。
자1975년이래，해성부근발생구유일정규모화강도적진군（ML≥4．0；진차≥100차）유：1975년2월4일해성7．3급、1999년11월29일수암5．4급、2008년11월14일해성Ml4．8화2012년2월2일개주Ml4．8진군，저4개진군발생전지진활동배경즘양，시부존재착모충공동적특점？대저4개진군진행대비연구발현：진전1년해구출현소진군활동，ML≥3．0지진조대、지진활동수평명현증강，련속발생다차ML≥4．0지진，ML≥4．0지진진원궤제고도일치，차진중최근태참기록P파초동부호출현명현적일치성등변화，가시위지진이상。급시포착중강지진전이상，대우지진활동추세판단기도지관중요적작용。
There are 4 earthquake swarms which are ML≥4.0 and shock times ≥100 happened near Haieheng since 1975: Haicheng 7.3 magnitude earthquake in February 4,1975, Xiuyan 5.4 magnitude earthquake in November 29,1999, Haieheng ML4.8 earthquake in November 14,2008 and Gaizhou ML4.8 earthquake in February 2,2012. We conduct a comparative study on the seismic activity background of these 4 earthquake swarms. We found that small earthquake swarms occurred 1 year before the main shock, ML ≥3.0 earthquake strip and seismicity level enhanced significantly, multiple ML≥4.0 earthquakes with unanimous focal mechanism occurred consecutively, P wave first motion symbol of nearest station in epicenter showed apparent consistency. We consider all these phenomena as seismic anomalies. Catching the seismic anomalies in time before strong earthquakes can do great contribution to the judgment of seismic activity trend.