台湾地区强震活动特征分析  

Analysis of strong earthquake activity characteristics in Taiwan

作　　者：卢显[1] 刘杰[1] 薛艳[1] 晏锐[1] 姜祥华 李祖宁[2] 邓世广 苑争一 Lu Xian;Liu Jie;Xue Yan;Yan Rui;Jiang Xianghua;Li Zuning;Deng Shiguang;Yuan Zhengyi(China Earthquake Networks Center,Beijing 100045,China;Fujian Earthquake Agency,Fuzhou 350003,China)

机构地区：[1]中国地震台网中心,中国北京100045 [2]福建省地震局,中国福州350003

出　　处：《地震学报》2023年第6期996-1010,共15页Acta Seismologica Sinica

基　　金：国家自然科学基金(41704062);中国地震局震情跟踪项目(2023010122,223020504)联合资助.

摘　　要：基于定性分析和Morlet小波分析方法,研究了我国台湾地区的主要构造带和强震分布特征。1900年以来台湾地区M_(S)≥7.0地震存在三个活跃时段:第一个活跃时段为1902—1925年,长达近23年;第二个活跃时段为1935—1978年,约43年;第三个活跃时段为1986—2006年,时长20年。台湾地区自2006年12月26日恒春海域发生M_(S)7.2地震之后,M_(S)≥7.0地震平静已近16年,为历史最长平静时段,存在开始新的活跃时段的可能。从区域分布看,台东地震带M_(S)≥6.9地震具有六个活动周期,大部分活动周期平均约为16年,每个活动周期均包含活跃和平静时段,所有M_(S)≥6.9地震均发生在活跃时段,统计显示台东地震带的活动强度自2002年进入第六个活动周期后逐渐减弱,直到2022年9月份台湾东带才再次发生M_(S)6.9地震,可能进入了新一轮活跃时段。台湾西带M_(S)≥6.0地震存在92年左右和14年左右的周期,1901—1993年为一个活跃-平静大周期(92年左右),1994年开始新一轮的大周期活动,同时,大周期又包含平均周期为14年左右的小周期。临近预报(nowcasting)方法计算的小震积累水平显示,台湾东带M_(S)≥7.0地震和台湾西带MS≥6.0地震具有较高的发震背景概率,台湾地区强震在年尺度上与华南地区中强地震具有一定的对应关系。Based on qualitative analysis and Morlet wavelet method,the distribution characteristics of the main tectonic zones and strong earthquakes in Taiwan,China are studied.The Taiwan,China can be divided into the Taidong seismic zone and the Taixi seismic zone,bounded by the Central Mountains.The former is mainly composed of the Huadong longitudinal valley fault,the coastal mountains and the sea area to the east of the coastal mountains.It is the region with the strongest seismic activity in Taiwan.The latter seismic zone mainly includes the western foothills and the western coastal plain.In addition,due to the influence of the Philippine Sea Plate pushing the Eurasian Plate towards the northwest,most earthquakes in Taiwan and surrounding waters are thrust-type earthquakes.There have been three active periods of M_(S)≥7.0 earthquakes in Taiwan since 1900.The first active period was from 1902 to 1925,which lasted nearly 23 years;the second was from 1935 to 1978,about 43 years;the third was from 1986 to 2006,lasting 20 years.Since the Hengchun sea area M_(S)7.2 earthquake in Taiwan on December 26,2006,Taiwan earthquakes above M_(S)7.0 have been quiet for nearly 16 years,which is the longest quiet time in history,and there is a possibility of a new active period.From the regional distribution perspective,M_(S)≥6.9 earthquakes in the eastern Taiwan had six active cycles,most of which lasted about 16 years on average.Each active cycle included active and quiet periods,and all M_(S)≥6.9 earthquakes occurred in active periods.Statistics show that the activity intensity of the eastern Taiwan had gradually weakened since 2002,when it entered the sixth active cycle.A new active period may have started since the Hualian M_(S)6.9 earthquake occurred in the eastern Taiwan on September of 2022.At the same time,the Morlet wavelet method was used to calculate the period spectrum of seismic activity of the Taidong seismic zone and the significance testing.The results showed that the 3-year and 16-year periods in the region passe

关 键 词：台湾地区 强震活动特征 活动周期 临近预报方法 

分 类 号：P315.5[天文地球—地震学]