寨山石刻所记地震考

寨山位于江苏邳州燕子埠镇陈楼村,山南麓的清代摩崖石刻有如下地震记载:"戊申季夏山东同时地震,房屋倒塌,压死人民不可胜数,较之嘉靖年压死王槐野、韩苑洛、马伯循之变为更甚焉.大清康熙七年六月十七日戌时地震.     

四川西昌1850年地震地表破裂特征研究

本文对则木河断裂带上各种地震地表破裂现象作了调查和时代方面的研究,结果表明,1850年西昌地震在西昌北的李金堡至宁南的松新间形成了长达90km的地震形变带。地震位错的最大水平位移为7m,垂直位移一般为0.5～2m,对地震形变带中的各种变形遗迹和地震地表破裂特征的研究表明,则木河断裂是这次地震的发震构造,震中位于大箐梁子一带,震中烈度达Ⅹ～Ⅺ。地震破裂的力学性质为左旋扭张,与则木河断裂晚第四纪以来的活动一致。地震破裂具有向南突出发展的不对称特点     

四川石棉—西昌地区地震区划研究

本文基于对石棉—西昌地区全新世断层活动与地震活动在时间上、空间上、强度上不均匀性的认识,结合四川省近廿年来对该区地震趋势估计,采用地震危险性概率分析方法,编制了此区50年超越概率10%的地震烈度和地表基岩水平峰值加速度区划图。区划结果表明,烈度和加速度的最高值均位于冕宁以南—西昌一带,这与该段全新世地表破裂最强烈、断错地貌和古地震遗迹相对集中、强震活动频繁具有较好的一致性;区划图等烈度线和等加速度线的总体分布形态近呈南北,与断裂走向基本一致。     

1850年西昌地震地表破裂带

着重从1850年西昌地震的地表破裂带调查入手,通过对地表破裂的分布特征、几何特征以及与各次级断层的关系的研究,对这次地震的震级、震中位置和震源深度进行讨论。     

邛海地倾斜观测系统的测量结果与地震

邛海地倾斜观测系统的测量结果表明:面倾斜观测精度可达10-7至10-8弧度;观测面倾斜的变化反映了邛海及其周围地区的,以M≥5.0地震活动为特征的地壳应力积累和释放过程;中强地震的短临前兆与大地震的趋势性和突发性两种前兆特征相似     

1605年武昌地震考

1605年湖北武昌府发生破坏性地震,由于历史资料的缺乏,地震的震级、震中位置未作确切的评定.本次工作主要是根据历史资料和武汉市地震地质背景对1605年地震的参数和构造作进一步评述.     

西昌地震中心站现代化综合分析系统简介

随着计算机科学的普及与发展,建设适合台站工作实际的综合分析现代化、正规化系统,是笔者多年来的心愿。经过３年的努力实践,终于以一种较为简便、实用的办法初步建成了西昌中心现代化综合分析系统。本系统建设的关键,简单地说,只需将一系列专业软件移植到Ｗｉｎ９５...     

1850年西昌地震地表破裂带的考察研究

根据实地考察研究结果，1850年西昌地震地表形变带全长约90km。现存的地表破裂形迹有地震断层、地震裂缝、地震沟槽、地堑、地震陷坑、冲沟及山脊位错、崩塌滑坡等。最大左旋水平位错5．7m，垂直位错3．8m，形变带严格沿则木河断裂展布。该次地震的发震构造应为则木河断裂，震级M≥7.5级。     

爱辉历史地震考

根据对黑龙江河谷地区本世纪以来地震资料的分析和新构造运动的研究，基本认定诗人所描述的地震是存在的。因此认为，此诗给黑龙江省及其邻近地区的地震活动研究提供了非常珍贵的历史地震资料。     

河南淅川M_L 4.6地震序列特征及发震诱因初探

2018年2月9日河南淅川发生M_L4.6地震序列,震中位于丹江口水库库区,依据有关地震序列判别规则和地震学分析方法,分析认为此次地震序列非前震序列,属主余型地震,后续无更大地震发生。2017年11月丹江口水库蓄水位首次达167 m,3个月后即发生此次M_L4.6地震序列,通过丹江口水库水位与地震的相关性,分析认为具有较明显的水库地震特征。     

2019年河南淅川ML 4.2地震震源深度测定

采用震源深度测定的确定性方法（PTD）和震源机制CAP反演法,对2019年11月30日河南淅川丹江口水库发生的M_L 4.2地震进行分析,重新计算了此次地震的震源深度。结果表明,2种方法所得到的震源深度基本一致,均约为7.0 km,与中国地震台网中心统一编目结果（7.1 km）相差不大,此结果可能表明地震监测台网相对较好的情况下,用不同方法测得的震源深度相差不大。     

Two categories of earthquake precursors,physical and tectonic,and their roles in intermediate-term earthquake prediction

I suggest that earthquake precursors can be divided into two major categories, physical and tectonic. I define physical precursor to be a direct or indirect indication of initiation or progression of an irreversible rupture-generating physical process within the preparation zone of a forthcoming earthquake. Tectonic precursor is defined as a manifestation of tectonic movement which takes place outside the preparation zone of an impending earthquake as a link in a chain of particular local tectonism in each individual area preceding the earthquake.Most intermediate-term, short-term and immediate precursors of various disciplines within the source regions of main shocks are considered physical ones. Some precursory crustal deformations around the source regions are, however, possibly tectonic precursors, because they may be caused by episodic plate motions or resultant block movements in the neighboring regions of the fault segments that will break. A possible example of this phenomena is the anomalous crustal uplift in the Izu Peninsula, Japan, before the 1978 Izu-Oshima earthquake ofM _s 6.8. Some precursory changes in seismicity patterns in wide areas surrounding source regions also seem to be tectonic precursors, because they were probably caused by the particular tectonic setting of each region. A typical example is a so-called doughnut pattern before the 1923 Kanto, Japan, earthquake ofM _s 8.2.Although most studies on earthquake precursors so far seem to regard implicitly all precursory phenomena observed as physical ones, the two categories should be distinguished carefully when statistical analysis or physical modeling is carried out based on reported precursory phenomena. In active plate boundary zones, where a practical strategy for earthquake prediction may well be different from that in intraplate regions, tectonic precursors can be powerful additional tools for intermediate-term earthquake prediction.     

1999年岫岩地震序列研究

用相对定位法对1999年11月29日辽宁省岫岩地区5.4级地震序列的前震、主震和余震进行了重新定位。结果是该序列的主震震源位置为40.538°N,123.026°E,深度为6.958km;重新定位的前震震中分布长短轴差别不大,分布在长轴约1.38km,短轴约1.23km,深度为6～11km的震源范围内,其中4级以上前震明显沿NW向分布,主震位于前震震中NW向分布的东南端;重新定位的余震明显沿NW走向分布,长轴约3.26km,短轴约0.79km,深度为5～12km,余震分布范围比前震分布范围大,主要是后期余震活动向SE向发展的结果。分析表明,1999年岫岩地震序列主要沿NW向分布,这个方向与1975年海城地震序列的NW向分布一致,与海城7.3级主震和岫岩5.4级主震震源机制解NW走向节面一致,也与海城 岫岩震区活动构造方向和岫岩主震的等震线长轴方向一致。并认为岫岩5.4级主震可能被前震触发,这为主破裂成核过程提供了一次实例。     

Morphological characteristics of the earthquake surface ruptures on Awaji Island, associated with the 1995 Southern Hyogo Prefecture Earthquake

Abstract The earthquake surface ruptures on the northern side of Awaji Island accompanying the 1995 Southern Hyogo Prefecture Earthquake in Japan consist of three earthquake surface rupture zones called the Nojima, Matsuho, and Kusumoto Earthquake Surface Rupture Zones. The Nojima Earthquake Surface Rupture Zone is - 18 km long and was formed from Awaji-cho at the northern end of Awaji Island to Ichinomiya-cho. It occurred along the pre-existing Nojima geological fault in the northern segment and as a new fault in the southern segment. The northern segment of the Nojima Earthquake Surface Rupture Zone is composed of some subparallel shear faults showing a right-step en echelon form and many extensional cracks showing a left-step en echelon form. The southern segment consists of some discontinuous surface ruptures which are concentrated in a narrow zone a few tens of meters in width. This surface rupture zone shows a general trend striking north 30°-60° east, and dipping 75°-85° east. The deformational topographies and striations on the fault plane generated during the co-seismic displacement show that the Nojima Earthquake Surface Rupture Zone is a right-lateral strike-slip fault with some reverse component. Displacements measured at many of the outcrops are generally 100-200 em horizontally and 50-100 em vertically in the northern segment and a few em to 20 em both horizontally and vertically in the southern segment. The largest displacements are 180 em horizontally, 130 em vertically, and 215 em in netslip measured at the Hirabayashi fault scarp. The Matsuho Earthquake Surface Rupture Zone striking north 40°-60° west was also found along the coastline trending northwest-southeast in Awaji-cho for ～1 km at the northern end of Awaji Island. The Kusumoto Earthquake Surface Rupture Zone occurred along the pre-existing Kusumoto geological fault for ～ 1.5 km near the northeastern coastline, generally striking north 35°-60° east, dipping 60°-70° west. From the morphological and geomorphological characteristics, the Nojima Earthquake Surface Rupture Zone can be divided into four segments which form a right-step en echelon formation. The geological and geomorphological evidence and the aftershock epicenter distributions show clearly that the distributions and geometry of these four segments are controlled by the pre-existing geological structures.     

对四川阆中和江油几次地震的调查和考证

通过对阆中３次地震和江油１次地震的调查和史料考证指出，１８４６年阆中地震实是１８５０年西昌地震；１８７９年甘肃武都南８级地震对阆中城垣并未造成“倾圮”、“坍塌”和“倾坍”；阆中二龙乡珍珠观地震石刻是１９２０年宁夏海原大地震对该地的影响；１８７９年５月江油５级地震实是同年７月甘肃武都８级地震的影响和波及。     

山西临汾地区3次ML≥4.0地震的异常特征分析

2001年至2003年山西临汾地区发生了3次ML≥4．0以上地震。介绍了这几次地震的基本参数、地震活动性分析结果以及地震前兆观测项目的异常变化特征，结合目前的地震活动特征、前兆资料的变化情况对临汾地区未来的地震情况进行了讨论。     

Textual research of Wudu earthquake in 186 B.C. in Gansu Province, China and discussion on its causative structure

On the basis of the textual research on the historical earthquake data and the field investigation of Wudu earth- quake occurred in 186 B.C., we suggest that the earthquake parameters drawn from the present earthquake catalogs are not definite and amendments should be made. The heavily-damaged area of this earthquake should be located between Jugan township of Wudu County and Pingding township of Zhouqu County. Its epicenter should be in the vicinity of Lianghekou in Wudu County with a magnitude of about 7~7 41 and an intensity of about IX~X. The major axis direction of the heavily-damaged area should be in the WNW direction that is approximately consistent with the strike of the middle-east segment of Diebu-Bailongjiang active fault zone, and the origin time should match up to that of the latest paleoearthquake event [before (83±46) B.C.] obtained by the trench investigation. Certain seismic rupture evidences are still preserved on this fault segment. Therefore, we propose on the basis of comprehensive analysis that the causative structure of the M 7~7 4/1 Wudu earthquake in 186 B.C. should be in the middle-east segment of Diebu-Bailongjiang active fault zone.     

华北地区震群活动的阶段性特征

通过对华北地区1970年以来震群活动的分析表明，唐山地震的震群活动显示出一定的迁移性和阶段性。应用流变介质包体孕震模型的理论进行了初步力学分析。张北地震的预测检验表明，震群活动的迁移性与阶段性对强震的中期预测具有一定指导意义。     

2003年日本北海道8.0级地震次声波特征研究

利用在北京昌平安装的次声三点阵, 记录了2003年9月26日日本北海道地震的前兆次声波和震后次声波。 实际记录的P-t曲线及波速波向图, 经快速傅立叶变换得到其三维动态频谱。 结果表明: ① 强震前2～7天能测到振幅很强、 方向可测的地震前兆次声波。 其频谱特点是: 振幅由弱(10～15 Pa)逐渐加强到(50～80 Pa)或更大; 先为短周期波(10～30 min), 紧跟着长周期波(30～50 min), 然后又出现更长的周期波, 最后长短周期的波一起出现连成一片(2～62 min); ② 地震前兆次声波的产生和记录较容易, 而当地次声波和震中次声波记录和识别比较困难; ③ 若两地的三点阵波向相交, 可预测震中位置。 故地震前兆次声波的测量研究, 有可能发展成为临震预报中一种有效的新方法