Fault Geometry and Departure of Precursors From the Epicenter

Different tectonic elements may play different roles and their deformation styles and types of anomalies are also different in the process of deformation.Such differences may be the cause of the phenomena of the departure from the region with obvious anomalies from the coming epicenter,which are called "departure of precursors from epicenter." From some new experimental and numerical modeling results,five types of deformation elements are identified according to their roles in the process of deformation in a region.They are the brake(or locked),slip,yield,sensitive,and valve elements.Spatial distribution of different elements,especially sensitive and slip elements,are discussed by taking the bend fault,extension,compression,and complex en-echelon faults as examples.These elements with different roles may overlap each other in some cases or be separated in other cases.It is obvious that for different fault geometry,the spatial layout of these elements is different and thus the position and style of

A METHOD FOR EPICENTER LOCATNG BY USING T WAVES

Two OBS arrays were deployed in the southern Okinawa Trough.Some of the OBS records revealedmany earthquakes with intensive T waves but ambiguous body waves.A new method using T waves for epicenter locating was developed that was found to be as precise as the body wave method for locatingepicenters when T waves are clearly recorded.

Study on the regional deviation of the mac-roscopic epicenters from relevant epicenters by rapid determination in Chinese mainland

The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Further study has proved the normal distributions exist in both the east and west parts of Chinese mainland partitioned along meridian 105°E. The empirical two-dimensional normal distribution functions for the deviations are presented in the paper. The results are of significance in reducing uncertainty of losses assessment immediately after a destroyed earthquake.

Tectonic Interpretation of the Epicenter Distribution Map of China

The 1:6,000,000 Epicenter Distribution Map of China compiled by the Center for Analysis and Prediction,SSB,has given more than 100,000 epicenters of large and small earthquakes.The images composed of these dots contain plenty of information concerning the structures in the middle-upper crust.Using the so-called visual seismic line method,a tectonic interpretation of the epicenter distribution map of shallow focus earthquakes in China mainland is given in this paper,and the seismotectonic patterns and dynamic characteristics of the Tianshan,AIxa-Qilianshan and Qinghai-Xizang(Tibet)seismic belts,the S-N central axis belt as well as Northeast China,North China,the middle and lower reaches of the Yangtze River and the southeast coastal areas are analyzed and interpreted.

打造数码印刷领域新航标——富士施乐epicenter高新技术体验中心正式启用

2005年3月2日．全球领先的文件处理专家——富士施乐宣布其倾力打造的epicenter高新技术体验中心在上海落成并正式启用。这是富士施乐斥巨资在亚太区4个城市共同打造的epicenter高新技术体验中心之一。epicenter高新技术体验中心的建立在业界创立了一种全新的服务模式．彰显了富士施乐为中国用户提供全球领先解决方案和优质服务的信心与决心。

Forecasting the Epicenter Area of a Future Strong Earthquake

It is clear from the literature data that the geometric characteristics of the seismogenic source are directly related to the nucleation of their strong earthquakes. Our study starts from the observation of the proximity relationship between the epicenter of a strong earthquake and the surface trace of the seismogenic source. The proposed model is based on the mathematical analysis of seismicity falling within an area, through a polynomial function to determine a curve. The experimental results of our model confirm that 97% of the epicenters of strong earthquakes are located near the concavities or at the inflection points of the polynomial curve. Only 3% of strong earthquakes are located at the edges of the analyzed areas, where the number of data is not significant. The proposed model makes it possible to locate, with good approximation, the areas most likely to be the site of future strong earthquakes.

Results of Geomagnetic Studies on the Problem of Forecasting Strong Earthquakes in Uzbekistan

The article is devoted to the problem of forecasting strong earthquakes by the geomagnetic method. The geomagnetic method is widely used on this problem in seismically active regions of the world as one of the promising, informative and operational geophysical methods. The results of long-term geomagnetic studies on the problem of forecasting strong earthquakes in Uzbekistan are presented. Geomagnetic studies were carried out on the territories of the Tashkent, Ferghana, and Kyzylkum geodynamic polygons in the epicentral zones of strong earthquakes that occurred. Long-term, medium- and short-term precursors of earthquakes have been identified. Anomalous changes in the geomagnetic field associated with the decline in aftershock activity were also revealed. The dependence between the duration of the manifestation of long-term magnetic precursors and the magnitude of earthquakes is determined. Absolute proton magnetometers MMP-1, MV-01 (Russia), and G-856 (USA) were used to measure the geomagnetic field.

基于POSC的测井曲线数据存储管理系统

在基于POSC标准的基础上 ,分析了POSCEPICENTER数据模型 ,对油田中普遍使用的LS716测井大块数据在磁盘和远程自动磁带库之间实现了一体化的数据管理 ,开发了数据加载、数据删除、头信息浏览和曲线回放等功能模块。该系统的特点是 ,管理信息加载到POSC数据仓中 ,而真正的数据体以外部数据文件的形式存放 ,使得大块数据的加载和提取速度大大提高。同时 。

Rapid Identification and Emergency Investigation of Surface Ruptures and Geohazards Induced by the M_s 7.1 Yushu Earthquake

The rapid identification based on InSAR technology was proved to be effective in our emergency investigation of surface ruptures and geohazards induced by the Yushu earthquake.The earthquake-generating fault of the Yushu earthquake is the Yushu section of the Garze-Yushu faults zone.It strikes NWW-NW,23 km long near the Yushu County seat,dominated by left-lateral strike slip,and appearing as a surface rupture zone.The macroscopic epicenter is positioned at Guo-yang-yan -song-duo of Gyegu Town（33°03＇11＂N,96°51＇26＂E）,where the co-seismic horizontal offset measured is 1.75 m.Geohazards induced by the Yushu earthquake are mainly rockfalls,landslides,debris flows, and unstable slopes.They are controlled by the earthquake-generating fault and are mostly distributed along it.There are several geohazard chains having been established,such as earthquake,canal damage,soil liquefying,landslide-debris flow,earthquake,soil liquefying,roadbed deformation,etc.In order to prevent seismic hazards,generally,where there is a visible surface rupture induced by the Yushu earthquake,reconstruction should be at least beyond 20 m,on each side,from it.Sufficient attention should also be given to potential geohazards or geohazard chains induced by the earthquake.

Tectonic Interpretation of the Earthquake istribution in the Contiguous Continent of the United States

With increasing high-quality geological and geophysical data it becomes clear that seismicity of the continents is characterized by linear patterns which are closely associated with tectonic features. The aim of this paper is to give reasonable interpretation for the earthquake distribution in the contiguous continent of the United States. Seismic lines and earthquake concentrated zones are defined, which reflect the characteristics of the continental seismotectonics. Similarities and differences in seismotectonics between the continental part of China and the contiguous continent of US are analysed. It is demonstrated that the spatial distribution of earthquakes can provide the information of the active structures in the earth's crust. The authors consider that the patterns of continental seismotectonics are not only controlled by the pre—existing tectonic frameworks and the current boundary dynamic conditions, but also possibly affected by dynamic factors of global tectonics at a higher level.

Crustal density structure of the southern segment of the Liaocheng-Lankao fault, China

The 1:200,000 middle-large scale Bouguer gravity anomaly data covering the southern segment of the Liaocheng-Lankao fault(SLLF)and its vicinity are analyzed with two methods.First,the Bouguer gravity anomaly data are decomposed by two-dimensional(2 D)wavelet to make the family of multi-scale modes correspond with density structure at different depths.Second,a two and half dimension(2.5 D)human-computer interaction inversion of the Bouguer gravity anomaly data are conducted with the constraints provided by two deep seismic sounding profiles(DSS1 and DSS2)crossing the study area to get the crustal density profiles.Based on the integrated study,we can draw the following conclusions:1)SLLF appears to be a deep fault with almost vertical dipping and rooted into the uppermost mantle;2)In the middle to upper crust SLLF shows an clear turning patterns and segmentation features;3)In the study area the epicentral distributions of the precisely re-located small earthquakes and the historical large earthquakes have a good correspondence with the turning patterns and segmentation features of SLLF;and 4)The results of the horizontal slices from 2 D wavelet decomposition show that there are significant differences in the density structure on the two sides of the fault.A well-defined concave structure with low density exists in the upper crust of the Dongming Depression on the west side of the fault,with the concave center being estimated at a depth of about 8 km.In contrast,the upper crust on the east side presents a relative thinner pattern in depth with a bit higher density.Meanwhile,the low-density structure in the middle crust underneath the fault is presumably caused by the uplift of the upper mantle materials and their intrusion along the deep rupture system.This paper clarified the inconsistency of fault system and epicenters of small earthquakes from upper to lower crust.The results indicated that the fault system plays an important governing role to the seismicity in this area.

Application of Fracture Gas Measurement to the Earthquake Studies in China

The earth is an enormous open system and the gas-releasing phenomenon of the crust is the major means of exchange of matters and energy at different crustal depth.Therefore,a powerful gas-releasing channel is actually a "window" to understand the subterranean physical and chemical variations as well as stress-strain changes.The releasing places,quantities and ways obtained by systematically observing and recording can reveal the pressure variation and opening state of channels in the crust,and furthermore provide important information for earthquake prediction,tectonic activity and monitoring of volcanic activity.The fracture-gas measurement has been applied widely to earthquake sciences and has played an important role.The authors introduced systematically the application situation and preliminary achievements in China,and pointed out that though this technique is at the beginning stage and not very sophisticated but its capacities for being easy-carrying,fast-operating and inexpensive,makes for a

Seismogenic Structure of the 1411 Southern Damxung (Damdoi) Earthquake with M=8 in Tibet

The seismogenic structure of the 1411 southern Damxung(Damdoi)earthquake with M=8 in Tibet is discussed in detail in this paper.It is pointed out that the Nyainqentanglha southern pediment fault is the seismogenic one of the 1411 southern Damxung(Damdoi)earthquake with M=8,and the macroepicenter is located at the intersection of the extensional shear fault within Nasego-Garbogo pull-apart basin and the secondary strike-slipping fault with larger amplitude of neotectonic activity at the southwestern side of the basin.Besides,there is obvious anomaly of the geophysical fields in the seismic area,indicating that occurrence of 1411 southern Damxung(Damdoi)earthquake with M=8 was not only controlled by the superstructure but also the background of deep-seated structure.

Service Biophysical Earthquake Prediction (Results and Prospects)

Analysis of the data suggests that the biophysical radiophysical sensing future earthquake epicenters is a promising direction for the medium-term and short-term forecasting of seismic events. We believe that it is necessary to create an international network of seismic monitoring biophysical for all seismically active areas of the globe. Information about biophysical precursors of earthquakes should be accumulated in the computer center, and operating information transmitted to all peripheral seismic monitoring station biophysical and services Ministry of Emergencies. In conclusion, I emphasize the value of such a centralized system of control over the “breath” of the Earth for the prevention and the prevention of industrial accidents in the mines, road transport, large power plants, etc.

Analysis of coseismic effect on temperature in the Three Gorges well network

Through the Three Gorges well network, we examine different coseismic changes in water temperature caused by local earthquakes since 2008, and offer a mechanistic explanation.The relations between the coseismic changes in water temperature and the parameters of distant and local earthquakes are deduced.

Seismicity of Kirov-Kazhim Aulacogen

In the last 200 years within the East-European platform more than 120 notable earthquakes occurred. One of the strongest earthquakes occurred in the south of Komi Republic in 1939.Since 1996 in territory of Komi Republic continuous seismic survey are conducted by station Syktyvkar(SYK).In the period of continuous survey,14 close seismic events were registered;eight of them occurred in the Kirov-Kazhim aulacogen.

Fault-Plane Solution of the Earthquake of 19 March 2005 in Monatele (Cameroon)

An earthquake of magnitude Ml = 3.04 was detected on the 19 of March 2005 at 11:49:18.31 (local time) by seven broadband seismometers located around Cameroon (Central Africa). Its epicenter has been relocated and found to be in Monatele (Cameroon) with latitude 4°26.34' and longitude 10°59.62'. The fault-plane solution calculated using double couple fault-plane solutions based on P-wave polarity readings, also taking into consideration the dextral nature of the Sanaga Fault (SF) underlying this region of the epicenter, is a strike-slip fault with a normal faulting component. The beach ball representation of this fault-plane solution has strike, dip and rake values of 289, 70, -169 for the principal fault plane and 195, 80, -20 for the auxiliary fault plane.