The Changma fault consists of four sub-faults,and is an important transform fault loca-ted between the Altyn Tagh fault and the western segment of the Qilian Mountains.In 1932,a M7.6 earthquake occurred in the fault,forming a rupture with a length of approximately 120 km that is composed of a series of fissures,fault scarps,offset terraces,and gullies.The maximum horizontal and vertical coseismic displacement was up to 5 .5 m and 1 .9 m,respectively.A trench excavated at Choushuiliugou in the middle-eastern segment of the Changma fault shows evidence of two paleoearthquakes:one is the Changma earthquake (1932)and the other earthquake oc-curred after 902 ± 44 a B.P..Combined with the results of previous studies,it was determined that seven paleoearthquakes have occurred in the Holocene.Base on characteristic earthquake model,we speculate an earthquake recurrence interval of approximately 1 ka,and part of paleo-earthquake events are not revealed by the trench.The trench also shows that the dip direction of the layer on the hanging wall is opposite to that of the down wall and low-angle fault.Based on a survey of dislocation landforms,the ratio of horizontal shortening and left strike slip was found to be 1∶5 .Eastern extrusion occurred in relation to the influence of Altyn Tagh fault activities in the study area.The change in fault trend has resulted in regional stress and differing angles between some of the fault segments,particularly the tip of sub-faults.Active fault characteristics are shown predominantly as sinistral strike-slip,but there is an evident increase in the component of horizon-tal shortening,which forms nappe activities on the hanging wall.It also forms a specific low-angle strike-slip phenomenon,which illustrates that the Changma fault has prominently presented crus-tal shortening since the late Pleistocene,in addition to absorbing much of the sinistral displace-ment of the Altyn Tagh fault,and playing a significant role in the tectonic transition between the Altyn Tagh fault and a series of faults in the western segment of the Qilian mountains.

华北东部海兴一带出露2座第四纪火山,即小山火山和大山火山,并在边庄附近隐伏了火山岩.野外考察和室内分析显示:小山火山为玛珥式火山,喷发方式为射汽岩浆喷发,影响范围仅限于火口附近,喷发物为火山渣、晶屑和火山灰;大山火山早期为爆破式喷发,后有岩浆侵入,喷发强度和规模均不大,产生了火山渣、火山集块岩和致密熔岩颈.边庄隐伏火山岩为气孔状和致密火山岩及火山角砾岩,喷发方式以弱爆破式喷发和熔岩流溢为主,喷发时代为早更新世.小山火山渣和边庄隐伏火山岩成分为玄武质,而大山火山岩SiO2含量低,属于霞石岩.氧化物含量不显示线性关系,说明它们之间不存在岩浆演化关系.3处火山岩均富集轻稀土,边庄隐伏火山岩富大离子亲石元素,无高场强元素Zr、Hf、Ti亏损,大山和小山样品强烈富集Th、U、Nb和Ta,明显负K和Ti.3处火山岩具有不同的岩石学和地球化学特征,具有相对独立的火山结构,虽均可能来自软流圈,但明显经历了不同的岩浆活动过程.

全面介绍了山东GPS地壳运动监测及管理信息系统的设计思路和框架以及软件开发方法,该系统以VC++、Matlab和WebGIS为开发基础,集成了设备监控、高精度数据解算、结果分析及应用,以及信息网络发布等功能,可为同类GPS观测网管理系统的研发提供良好的借鉴.

本文选取山东地区2个Ⅲ类场地的工程地质勘探及土层剪切波速等资料,将土层厚度按5个深度段,每个分段给出了4个土层剪切波速的改变量,通过改变不同深度段土层剪切波速,建立了19种土层地震反应分析模型,分析了不同深度段,不同概率水平下土层剪切波速的变化对场地地震动参数的影响.研究表明,不同深度段土层剪切波速的变化对场地地震动参数的影响有差异.具体表现为,土层剪切波速的改变在1-10m、11-40m和地震输入界面处三个深度段对地震动加速度峰值影响较大;其中,41-70m和71-100m两个深度段剪切波速的改变对地震动加速度峰值影响小;在土层深度1-10m时,剪切波速降低,峰值变大,剪切波速的改变与峰值的改变呈负相关;在其它深度段,剪切波速降低,峰值变小,剪切波速的改变与峰值的改变呈正相关.剪切波速的改变在1-10m和11-40m两个深度段对地震加速度反应谱影响较大;在41-70m、71-100m和地震输入界面三个深度段对地震加速度反应谱影响很小.

使用2009 ～2011年山东地震台网记录到的71次网内地震波形资料,采用2个地震台站的到时差所构造的震中轨迹近似满足双曲线方程,并结合单台测定的方位角及震中距信息,使用Voronoi图对震中位置加以约束的技术思路,实现地震定位精度的逐步提高.与山东地震台网观测报告给出的震中位置进行对比分析,结果表明:单台定位平均误差为18.3 km,双台定位平均误差为16.6 km,三台定位平均误差为10.7 km.

Case in Ⅱclass site,selected data of engineering geological exploration and shear wave velocity from two sites in Shandong,the soil seismic response model is established by changing the velocity of different depth.The differential probability ground motion parameters under the conditions of changes in shear wave velocity of different depths paragraph are calculated and analyzed.The results show that the change of shear wave velocity peak acceleration of ground motion affect and the characteristic period are different.The results of this study for further research may provide reference for the soil shear wave velocity test uncertainty on the impact of ground motion parameters and reasonably determined ground motion parameters.

Based on the concept of the Voronoi diagram and distribution of earthquake conforming to the distribution of hyperbola approximately,a new methods for earthquake rapid location in the earthquake early warning is presented that using the V-diagram and hyperbola jointly.The earthquakes recorded by the digital seismic network of Qinghai province are relocated with the new method.The result shows that the new method can meet the need of location precision and the timeliness of rapid report in the earthquake early warning,and is better than other ways.So the method has a good prospect of application in the earthquake early warning system.

In a earthquake early warning system,the ability to quickly locate devastating earthquake is very important.In this paper a new method to estimate earthquake epicentral region,hyperbolic curve range and epicenter point from only the three earliest P-wave arrival times in a seismic network is developed.In the method the constraint conditions that some stations record P arrivals the others do not record P arrivals,and seismic wave travelling characteristics are considered fully to improve earthquake epicentral location accuracy.The method is applied to P-wave seismic data from the Virtual Seismic Network of Shandong province with 79 stations for 425 earthquakes in 2009-2010,the results show agreement with actual earthquake epicentral locations.The method can satisfy the real-time and accurate need in the earthquake early warning system.

Based on initial motions of the three-component P wave data recorded at a single station in Shandong Seismic Network,compared with actual results,we established the optimum technical scheme of measuring earthquake azimuth and the stations applying to earthquake early warning from two kinds of measuring earthquake azimuth methods and seven kinds of data preprocessing methods.We improved the method of determining earthquake magnitude and epicenter distance,and got the best statistical relation between epicenter distance and peak velocity using envelop characteristic parameters of 2s waveforms before the P arrivals.We also got magnitude scaling relation based on the envelope characteristic parameter.The quick measuring method for earthquake epicenter and magnitude exhibits practical application prospect in real-time earthquake early warning.

On the records of digital seismographs, the characteristics of three branches (PKPab, PKPbc, PKPdf) of the core phase PKP, with their epicenter in the range of 145°to 160°, were analyzed in details on basis of several examples. It is indicated that the three branches of the PKP phase could be well recorded by China seismic network when a far-teleseism occurred in South America. Their characteristics were also analyzed, providing some helpful attempts on analysis of far-teleseimic phases for people on seismic stations. It is indicated that the analysis of the three branches of PKP phase will be helpful to improve the accuracy of phase analysis and earthquake location of the entire China seismic network.

The earthquake parameters?occurrence time?the epicentres and the magnitudes are compared by the data of Ge'ermu station and the catelogue by Qinghai seismological bureau from Sep.to Dec.in 2000. The results show that digital instrument is better than the analog instrument.