青海钻孔应变映震效能研究

利用青海省6套YRY-4分量钻孔应变仪2007—2015年的观测资料,将该地区符合扫描范围的地震从震前异常和同震特征两方面进行研究。结果显示:湟源、德令哈分量钻孔应变差应变曲线地震前大多有短期超差异常;分量钻孔应变仪的同震响应幅度与震级、震中距都有关。同一地震,多台仪器多数情况同震响应幅度与震中距成反比,少数成正比;一般单台仪器同震响应幅度与地震震级成正比关系,震级越大同震响应幅度越大;分量钻孔应变仪的同震响应延迟时间大多与地震震中距成正比,震中距越远同震响应延迟时间越长;分量钻孔应变仪同震响应持续时间与震级基本成正比,震级越大同震持续时间越长。     

安西地震台洞体长短基线倾斜仪同震响应对比分析

基于安西地震台洞体倾斜形变观测所用长基线DSQ型水管倾斜仪和短基线VP型垂直摆倾斜仪的数据产出资料,根据仪器记录的地震事件的最大响应幅度、响应延迟时间和响应持续时间等,对两套仪器的同震响应特征进行了对比分析。结果表明:两套仪器的响应延迟时间与震中距成正比、响应持续时间与震级成正比;水管倾斜仪最大响应幅度与震级成正比;垂直摆倾斜仪最大响应幅度与震级、震中距有关。     

海南五指山形变台DSQ型水管倾斜仪与VP型垂直摆倾斜仪同震响应对比分析

选取2014-2018年海南五指山形变台DSQ型水管倾斜仪和VP型垂直摆倾斜仪记录的20个地震的同震响应资料,对比分析2套仪器的同震响应特征。结果表明：在震中距相近时,二者响应幅度、同震响应持续时间与震级呈正相关;除少数地震外,在震级相近或相同时,二者地震响应幅度与震中距呈负相关;地震响应延迟时间与震中距有关,二者均呈正相关;对于同一地震,一般VP型垂直摆倾斜仪的最大响应幅度较大,且同震持续时间较长。     

乌加河地震台PET重力仪同震响应特征研究

基于乌加河地震台重力仪观测条件,从面波延迟时间、面波传播速率、最大变形幅度、同震持续时间、响应形态和初动方向6个方面研究了乌加河地震台PET重力仪对国内外6次地震的同震响应特征。研究结果显示:同震响应的面波延迟时间与地震震中距离具有较好的正相关性;同震响应的波幅与地震震级大小及震中距有关;同震波的持续时间与震级有关;远距离地震的同震波一般表现为脉冲形式;初动方向没有规律。此研究有助于对PET重力仪的深入了解,同时也为地震相关参数的提取提供了参考依据。     

河北易县地震台水管倾斜仪与垂直摆倾斜仪同震响应分析

利用河北易县地震台DSQ型水管倾斜仪与VS型垂直摆倾斜仪记录的2005—2015年数据资料,分析两种地倾斜观测仪器同震响应的特征及响应幅度与震中距、震级的关系。结果表明:(1)DSQ型水管倾斜仪对远震响应幅度大,同震响应幅度与震级呈正比,与震中距呈反比;VS型垂直摆倾斜仪对近震响应幅度大,与震级、震中距无明显的线性关系。DSQ型水管倾斜仪的同震响应延迟时间比VS型垂直摆倾斜仪短,且与震中距呈正比;(2)两种地倾斜观测仪的地震响应持续时间与震级呈正比,VS型垂直摆倾斜仪对中小地震的响应持续时间比DSQ型水管倾斜仪长。     

安康地区地形变资料同震形变波特征分析

利用安康地区3个形变台2017—2020年地形变资料,对比分析6套形变仪器的映震能力,并从面波延迟时间、最大响应幅度及同震持续时间等方面系统探讨同震形变波的特征参数与震源参数的关系,获知形变仪器映震效能的影响因素和同震形变波的物理分布特征。结果表明:形变仪器的映震能力受仪器自身响应特性、地下介质特性及仪器系统误差等因素的影响;同震形变波物理分布特征表明面波延迟时间与震中距、同震响应最大幅度与震级、同震持续时间与震级及震中距之间存在一定的比例关系。      

2022年泸定6.8级地震GNSS同震形变场及其约束反演的破裂滑动分布

2022年9月5日四川省甘孜州泸定县发生6.8级地震,地震发生在川滇菱形块体东边界鲜水河断裂磨西段西侧附近.本文基于震中350 km范围内中国大陆构造环境网络和中国地震科学实验场118个GNSS连续站数据,观测获得了精细的同震形变场,结果显示：同震形变跨发震断层呈空间对称分布,表明本次地震具有显著的左旋走滑特征;记录到的最大同震形变发生在震中距40 km的SYD5(石棉安顺场)站,东西向和南北向形变量分别达到-22.0±1.2 mm和11.6±0.9 mm,震中距100 km以外测站的水平同震形变均小于5 mm;垂向同震形变不显著.结合走向163°和倾角77°的发震断层模型,本文对发震断层面的同震破裂滑动分布进行了反演,结果显示：同震滑动主要集中在主震东南侧余震空区0～15 km深度范围内,且破裂达到了地表,同震释放的地震矩与矩震级为M_W6.57地震相当.结合理论同震形变场、主应变场和邻近区域主要活动断裂库仑应力变化的空间分布特征,本次可能导致处于强闭锁和地震空区的安宁河断裂石棉—冕宁段未来发震风险性增强.     

GNSS观测的2021年5月22日玛多MS7.4地震同震位移及其约束反演的滑动破裂分布

2021年5月22日青海省果洛州玛多县发生M_W7.4地震,此次地震产生的地表破裂在空间上表现出明显的分段特征.本文基于不同来源的GNSS连续观测网数据获取了此次地震的精细三维同震形变场,结果显示:观测到的最大水平位移量达到280 mm,最大垂直形变量仅为25 mm,暗示此次地震的逆冲分量较小;此次地震具有较为明显的左旋走滑特征,同震形变基本对称,在NW-SE向的影响范围更广,该方向上水平同震形变大于3 mm的震中距范围超过500 km.进而,本文以余震精定位结果和GNSS观测到的三维同震形变场为约束,构建了地表破裂线为折线、倾角为85°、倾向西南的断层模型,反演了滑动破裂分布.结果显示:滑动破裂分布在震中两侧不均匀,均破裂到地表,破裂深度达到15 km左右,最大滑移量为4.73 m,计算的矩震级为M_W7.37.该结果与余震精定位结果具有很好的一致性,破裂的极值区正好位于早期余震空区,推测该余震空区未来的发震风险性较低.最后基于反演结果模拟计算了震中区域形变和应变场,结合应变值在断层地表迹线东南侧呈现挤压特征和已有的研究成果,推测此次地震增强了巴颜喀拉块体在东部地区挤压应力的积累特征,导致东部地区发震危险性增强,值得后续跟踪研究.     

拉萨地震台PET重力仪同震响应特征

从面波延迟时间、初动方向、波幅、同震持续时间等4个方面研究拉萨台PET重力仪的同震响应特征,结果表明：（1）同震响应的面波延迟时间与地震震中距离具有较好正相关性;（2）初动方向没有规律;（3）同震响应的波幅不仅与地震震级大小有关,还与震中距远近有关;（4）远震的同震波一般表现为脉冲形式,近震除了脉冲外,还有阶跃;（5）同震波的延续时间与震级没有明确的比例关系.这有助于对重力仪器进行深入的了解,可以为未来西藏地区监测台网布设方案提供参考数据.     

gPhone重力仪和VP宽频带倾斜仪同震响应对比

利用莆田台gPhone重力仪和VP宽频带倾斜仪记录到的地震进行同震响应特征对比分析,结果表明：(1)同震响应延迟时间同震级呈负相关、同震中距呈正相关,同震响应持续时间、波幅的变化主要取决于震级,同震中距没有必然联系;(2)重力仪记录到同震响应地震事件个数多于宽频带倾斜仪,从同震响应持续时间、波幅变化等同震响应特征看,重力仪的记震能力优于宽频带倾斜仪,但二者同震响应延迟时间没有差异。     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases