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The tectonic settings and seismogenic tectonics of the M5.7 Jiujiang earthquake in 2005,Jiangxi Province,china

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Science china Earth Sciences 2008年第5期51卷 640-653页

作者： LI ChuanYou1, ZENG XinFu2 & ZHANG JianXi3 1 institute of geology, china earthquake administration, beijing 100029, china 2 Jiangxi earthquake administration, Nanchang 330039, china 3 beijing earthquake administration, beijing 100080, china 1. institute of geology China Earthquake Administration Beijing 100029 China 2. Jiangxi earthquake administration Nanchang 330039 China 3. beijing earthquake administration Beijing 100080 China

The M5.7 Jiujiang earthquake in 2005 was a mid-strong one, stronger than expected to occur in the region. This paper discusses the neo-tectonic settings of this earthquake, and it is thought that the earthquake region is located in the transitional belt, a potential area inducing weak to moderately strong earthquakes, between two large different tectonic units. The results of the reconnaissance work and on-the-spot investigation after earthquake indicate that the occurrence of the M5.7 Jiujiang earth- quake is closely related with the NE-trending fault on the western margin of Ruichang Basin. From its controlling to the landforms and Quaternary depositions, geological profiles, ESR dating, etc., the ac- tivity of the Dingjiashan-Langjunshan fault bounding the basin is discussed. It suggests that this fault displays an active one in Middle Pleistocene by the outcrop. Based on the activity of the fault, and the direction and location of the ground fissures, the isoseismal lines and the nodal plane of the focal mechanism solution, it is inferred that the Dingjiashan-Langjunshan fault is the seismogenic tectonics of the M5.7 Jiujiang earthquake, and the intersection point between this fault and the active NW ones is the possible origin of location of this earthquake. Our study shows that this earthquake is not an event exceeding expectation, and that the active and invisible characteristics of the causative fault are typical in the eastern area of china.

关键词： Jiujiang earthquake tectonic settings Dingjiashan-Langjunshan fault activity seismogenic tectonics

A circum-earth shear zone at low-latitudes and episodic large earthquakes in it and the circum-Pacific seismic zone

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Science china Earth Sciences 2006年第9期49卷 897-903页

作者： MA Zongjin1, DU Pinren1, REN Jinwei2 & GAO Xianglin1 1. institute of geology, china earthquake administration, beijing 100029, china 2. institute of earthquake Science, china earthquake administration, beijing 10003., china 1. institute of geology China Earthquake Administration Beijing 100029 China 2. institute of earthquake Science China Earthquake Administration Beijing 100036 China

Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13 large faults dominant with strike-slip. We call it a global shear zone at low-latitudes (E system). By statistical analysis of temporal distribution of earthquakes Mw≥7.5 in the E system and the circum-Pacific (P system) during 1900―2003, we find that there exist quasi-episodic and alternative activities in and between these two systems. This phenomenon is likely associated with the half-sphere oscillation in dilation and contraction and the change of the Earth’s rotation rate.

关键词： shear zone, circum-Pacific zone, great earthquake, quasi-episode.

The upper mantle structure of the Tibetan Plateau and its implication for the continent-continent collision

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Science china Earth Sciences 2005年第8期48卷 1158-1164页

作者： WU Qingju1, ZENG Rongsheng1 & ZHAO Wenjin2 1. institute of Geophysics, china earthquake administration, beijing 100081, china 2. institute of geology, china Academy of Geological Sciences, beijing 10003., china 1. institute of Geophysics China Earthquake Administration 100081 Beijing China 2. institute of geology China Academy of Geological Sciences 100037 Beijing China

The upper mantle structures of Himalayas-Tibet have been obtained from the mi-gration of receiver functions of the teleseismic events recorded by INDEPTH-III. The result of migration imaging shows a dipping interface subducting northward from the depth of 100 km to the 410-km discontinuity underneath southern Tibet. It indicates that the lithospheric mantle of the Indian continent had been detached from the crust and deeply subducted to the upper mantle of Eurasia during the Indo-Eurasian collision. This kind of continent-continent collision process is fundamentally different from the oceanic collision.

关键词： Tibetan Plateau, receiver function, upper mantle structures, Indo-Eurasian collision, dipping interface.

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

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Science china Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2 & CAI YongEn2 1 institute of Crustal Dynamics, china earthquake administration, beijing 100085, china 2 Department of Geophysics, Peking University, beijing 100871, china 1. institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China 2. Department of Geophysics Peking University Beijing 100871 China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2×1020 Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 20.7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

Velocity structure and active fault of Yanyuan-Mabian seismic zone―The result of high-resolution seismic refraction experiment

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Science china Earth Sciences 2008年第9期51卷 1284-1296页

作者： WANG FuYun1↑, DUAN YongHong1, YANG ZhuoXin1, ZHANG chengKe1, ZHAO JinRen1, ZHANG JianShi1, ZHANG XianKang1, LIU QiYuan2, ZHU AiLan2, XU XiWei2 & LIU BaoFeng1 1 Geophysical Exploration Center, china earthquake administration, Zhengzhou 450002, china 2 institute of geology, china earthquake administration, beijing 100029, china 1. Geophysical Exploration Center China Earthquake Administration Zhengzhou 450002 China 2. institute of geology China Earthquake Administration Beijing 100029 China

The authors processed the seismic refraction Pg-wave travel time data with finite difference tomography method and revealed velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan Province. The following are the results of our investigation. The upper crust of Yanyuan basin and the Houlong Mountains consists of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct, and gently west-dipping structural plane. Between model coordinates 180-240 km, P-wave velocity distribution features steeply inclined strip-like structure with strongly non-uniform high and low velocities alternately. Xichang Mesozoic basin between 240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity variations are very strong and the interface between the two layers fluctuates a lot. The Daliang Mountains to the east of the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s. From 130 to 150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be related with Permian magmatic activity. The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front. Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement. Anninghe fault and Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the base-ment. At a great depth, Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement. The east margin f

关键词： western Sichuan high-resolution seismic refraction active fault velocity structure of the upper crust

Average slip rate, earthquake rupturing segmentation and recurrence behavior on the Litang fault zone, western Sichuan Province, china

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Science china Earth Sciences 2005年第8期48卷 1183-1196页

作者： XU Xiwei1, WEN Xueze2, YU Guihua1, ZHENG Rongzhang1, LUO Haiyuan2 & ZHENG Bin2 1. institute of geology, china earthquake administration, beijing 100029, china 2. earthquake administration of Sichuan Province, chengdu 610041, china 1. institute of geology China Earthquake Administration 100029 Beijing China 2. earthquake administration of Sichuan Province 610041 Chengdu China

The Litang fault zone (LFZ) is an active fault zone within the northwestern Sichuan sub-block. Field investigation reveals new evidence for its late Quaternary offset, neoteric earthquake ruptures and surface-rupturing segmentation, from which long-term slip-rates, char-acteristic earthquake magnitudes and recurrence intervals on the fault zone are estimated. This study shows that the LFZ consists of three subordinate faults, and they are the northern Maoyaba fault, Litang fault and Kangga-Dewu fault, respectively. All of them are dominated by left-lateral strike-slip with reverse dip-slip component on different segments. Based on offset landforms and ages of relevant deposits collected from seven sites, it is estimated that the average left-lateral slip-rate on the LFZ reaches 4.0±1.0 mm/a in the past 14 ka BP, and vertical (reverse) dip-slip rate in the range of 0.1―1.8 mm/a. Three subordinate faults are independent earthquake rup-turing segments, on which the maximum moment magnitude of the characteristic earthquakes is estimated to be 7.0―7.3, and their average recurrence interval to be 500―1000 a. The latest earthquake ruptures occurred 119±2 years ago on the northern Maoyaba fault, about 1890 AD on the Litang fault, and in 1948 AD on the Kangga-Dewu fault, and this may indicate a unidirectional migration for surface rupturing earthquakes along the Litang fault zone, related to stress trigger-ing between the segments.

关键词： Litang fault zone, slip rate, earthquake rupturing segmentation, recurrence interval.

Real-World Treatment Adherence to Smoking Cessation Medications and Association with Treatment Outcome—27 Centers,china,2017–2022

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china CDC weekly 2024年第22期6卷 522-529,I0001-I0003页

作者： Anqi cheng Zhao Liu Xinmei Zhou Zheng Su Dan Xiao Chen Wang the china National Tobacco Cessation Cohort Study(CNTCCS)Study Group Department of Tobacco Control and Prevention of Respiratory Disease Center of Respiratory MedicineChina-Japan Friendship Hospital/WHO Collaborating Center for Tobacco Cessation and Respiratory Diseases Prevention/National Center for Respiratory Medicine/National Clinical Research Center for Respiratory Diseases/Institute of Respiratory MedicineChinese Academy of Medical SciencesBeijingChina Department of Pulmonary and Critical Care Medicine Center of Respiratory MedicineChina-Japan Friendship Hospital/WHO Collaborating Center for Tobacco Cessation and Respiratory Diseases Prevention/China National Center for Respiratory Medicine/China National Clinical Research Center for Respiratory DiseasesBeijingChina Chinese Academy of Medical Sciences and Peking Union Medical College BeijingChina 不详

What is already known about this topic?Medication non-adherence significantly impedes smoking cessation *** effective smoking cessation medications are accessible in china,realworld adherence and its correlation with treatment outcomes remain largely *** is added by this report?From December 2017 to January 2022,1,120 participants were recruited from 27 centers in all seven geographical regions of *** revealed that only 38.2%of smokers adhered to the prescribed 12-week smoking cessation treatment and those with a higher education level were more likely to be *** addition,smokers with good adherence were more likely to successfully quit *** are the implications for public health practice?The data obtained could enhance our understanding of smoking cessation practices in *** adherence is a crucial strategy to enhance the effectiveness of smoking cessation treatments and management provided to smokers.

关键词： china smoke likely

Anatexis in Himalayan crust:Evidence from geochemical and chronological investigations of Higher Himalayan Crystallines

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Science china Earth Sciences 2005年第9期48卷 1347-1356页

作者： YANG Xiaosong1, JIN Zhenmin2 & MA Jin1 1. State Key Laboratory of earthquake Dynamics, institute of geology, china earthquake administration, beijing 100029, china 2. Faculty of Earth Sciences, china University of Geosciences, Wuhan 430074, china 1. State Key Laboratory of earthquake Dynamics Institute of Geology China Earthquake Administration 100029 Beijing China 2. Faculty of Earth Sciences China University of Geosciences 430074 Wuhan China

Migmatization in Higher Himalayan Crystallines (HHC) results from anatexis. The widely distributed migmatites in HHC are an important clue to investigate the relationship be- tween anatexis and the origins of Higher Himalayan leucogranites (HHL), and to understand the effect of anatexis on crustal evolution during the post-collision period. We studied in detail the chemical features of three basic constituent parts of the migmatites, i.e. leucosome, mesosome and melanosome, and determined the K-Ar ages of leucosomes. Our studies indicate that type-I leucosome is the product of crystallization of melt generated by partial melting of mesosome at source region, but type-II leucosome and HHL probably underwent crystallization differentiation of plagioclase during melt aggregation and migration. The age of 22.67 Ma of Type-I leucosome, which is a little older than the beginning of MCT movement, indicates that anatexis may have played an important role in the formation of MCT. That the ages of type-II leucosome (ranging from 14.82 to 18.37 Ma) are consistent with that of HHL provides new chronological evidence for the relationship between migmatization and HHL. We obtained a very young age of 6.23 Ma of Type-II leucosome that provides new time constraint on magma activity in the central segment of Higher Himalayas.

关键词： Higher Himalayan Crystallines, migmatite, anatexis, leucosome, K-Ar age.

A preliminary study on seismic design criteria of offshore platforms in Bohai Sea of china

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earthquake Engineering and Engineering Vibration 2010年第2期9卷 223-231页

作者： Peng Yanju1,Lu Yuejun1,Yan Jiaquan2,Tang Rongyu1,Wang Junqin3 and Li Jiagang3 1. institute of Crustal Dynamics,china earthquake administration,beijing 100085,china 2. institute of Geophysics,china earthquake administration,beijing 100081,china 3. beijing Research Center of china National Offshore Oil Corp.,beijing 100027,china institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China

This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 200 and 1000 - 2500 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.

关键词： fixed offshore platform seismic design level seismic design objective return period Bohai Sea