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1.
地震学家里克特。美国人,1900年出生于美国俄亥俄州。1920年毕业于加利福尼亚州斯坦福大学,后进入加利福尼亚州理工学院进修。1927年任帕萨迪纳地震研究所助理研究员,在地震学家伍德指导下进行地震研究工作。1928年获加州理工学院物理学博士学位。1937年为地震学助教,后升为  相似文献   

2.
地球物理学家,中国科学院地学部委员顾功叙先生,1908年7月5日出生在浙江省嘉善县,汉族。1929年于上海大同大学毕业后,任浙扛大学物理系助教。1934年赴美国留学,先后在科罗拉多州矿业学院和加利福尼亚理工学院学习及做研究工作,并获科罗拉多州矿业学院硕士学位。1938年回国后任前北平中央研究院物理研究所研究员。  相似文献   

3.
据美国国际交流署华盛顿1981年1月8日电报导,美国和中国的地震科学家已开始了一项在中华人民共和国设立一系列强烈地面运动地震测量仪的联合研究计划。这是由全国科学基金会减轻地震灾害计划发起。这项计划的主要调查人员是加利福尼亚理工学院应用力学教授威尔弗雷德·伊万博士、美国地质调查局的戴维·博尔博士和南加利福尼亚大学的邓大量博士。  相似文献   

4.
墨西哥国家理工学院的研究人员近日发明一种地震预警系统,该系统可以在地震波传到前200s通过手机使人们获得预警信号。  相似文献   

5.
1989年10月旧金山地区地震后最令人可怕的景象是由煤气管道引燃而后在整个街区肆虐的大火。要是警报系统能在地震袭击一城市之前一二分钟响起警报,就能减轻这类灾害。警报可安装在诸如公用事业公司等关键场所,以便预先把煤气总管道关闭。美国全国大概有五六位科学家正在研制这种实时地震警报系统。这些系统依据的原理是:地震波要比无线电波传播得慢。通过卫星传送,这些系统能把重要设施与测量地面运动的仪器联接起来。在麻省理工学院,由地球、大气和行星科学系教授托克索茨(M.N.Toks(?)z)领导的小  相似文献   

6.
强震来临之前预先发出警告的地震预警(EEW)系统是减轻地震灾害的关键。目前运行的地震预警系统基于的是点源假设,由于忽视有效源的效应导致震级幅度被低估,从而在大地震事件中效用受限。在这里,我们探讨地震预警使用活断层附近的小孔径地震台阵来实时表征破裂尺寸的概念。反向追踪台阵波形可实时估计出破裂前沿的范围(代表破裂的尺寸)和方向性,为现有的地震预警系统针对M7地震提供附加的地震预警性能。我们在模拟的实时环境中对其实际运行,并分析由美国地质调查局帕克菲尔德密集地震台阵(UPSAR)监测的2004年加利福尼亚帕克菲尔德M6地震记录,以及由加利福尼亚圣迭戈强震传感器监测的2010年El Mayor-Cucapah M7.2地震记录。我们发现基于较小事件的数据校正由美国地质调查局帕克菲尔德密集地震台阵下方的倾斜结构引起的反方位角的偏差至关重要。我们估计的破裂长度比其他研究推断的长度短30%,但是对于地震预警的目标仍然是合理的。我们把这种差异归因于破裂方向性效应及单个台阵视野有限。这种方法的准确度也许会随视野重叠的台阵网而改善。我们对此通过九州和北海道北部两个Hi-net台网的台站群追踪2011年日本东北地震的破裂来予以说明。所得结果与远震反投影结果一致且得到了破裂长度及方向性的合理估计值。与提出的其他有限断层地震预警方法相比,该台阵方法受全球定位系统或地震台网的粗略性影响较小,提供了破裂的高频特征而对某些结构获得了比地震动更适合的预报因子。  相似文献   

7.
讯零     
加利福尼亚处在危险中加利福尼亚地震安全委员会最近发表了一份题为《加利福尼亚处在危险中:1987—1992年的地震灾害减轻》的报告。据这项计划的负责人麦克劳德(John Mcleod)称,该报告详述了一项全面的州立地震安全计划以及从现在起到本世纪末关于加利福尼亚减轻地震灾害的建议。在第一个5年计划中所建议的66项首要工作为州政府、州议会、地方选举官员、政府机构负责人和私人部门决策人提供了减轻未来地震灾害的“蓝图”。这项计划最优先考虑生命安全、并重点放在提高州的应急反应能力及减少该州危险建筑物的数目上。  相似文献   

8.
振动台实时耦联动力试验系统构建解决方案   总被引:2,自引:1,他引:1  
实时耦联动力试验(RTDHT)是一种将物理模型试验和数值求解计算实时耦联在一起进行整体结构动力反应分析的新型结构动力试验方法。构建实时耦联动力试验系统将面临数值子结构实时计算、数据实时传输、加载器精确加载等问题。本文首先以清华大学新近建成的一套基于振动台的实时耦联动力试验系统为例,对试验系统构建中面临的问题以及相应的解决方案进行了阐述,对构建实时耦联动力试验系统提出了一些指导性的建议。随后简要介绍了利用该系统已经进行的一些实时耦联动力试验,并对实时耦联动力试验可能的应用前景进行了探讨。  相似文献   

9.
加利福尼亚综合地震台网(CISN)正在为加利福尼亚州开发一种地震预警(EEW)示范系统。在加利福尼亚综合地震台网震动警报(ShakeAlert)项目中,正在检验3种算法,其中之一是基于台网的地震警报系统(ElarmS)的地震预警系统。在过去的3年中,ElarmS算法经历了大量重新评定和解决技术与方法的若干挑战。在新的生产级产品,即ElarmS第2版(简称ElarmS-2或E2)中,对算法的改进扩大到适用当前地震台网的布局,改进了硬件和软件的性能,提高了预警处理速度和警报的准确性。E2设计为模块化的代码,由改进关联器的新事件监测模块组成,可以更迅速地与少数触发关联匹配,同时也增加了几个新的警报过滤检查,从而帮助最大限度地减少虚报。本文概述了这个新的在线实时系统的方法,总结了其性能。从2012年10月2日到2013年2月15日的在线操作性能来看,平均而言,在所有加利福尼亚发生的地震事件中,ElarmS系统在初至P波到达后8.68±3.73s发布预警。这一时间在台站仪器密集地区减少了2s。震级和发震时刻的标准差为0.4级和1.2s,定位误差中值为3.8km。在加利福尼亚发生的29次地震(MANSS3.5)中,E2成功检测到26次,发布了两次虚报。E2现正传送警报给震动警报系统,由震动警报系统发布给测试用户。  相似文献   

10.
亚洲理工学院防灾减灾国际培训班概况亚洲理工学院防灾中心(ADPC-AIT),是国际减灾十年(IDNDR)项目在亚太地区的牵头单位。为了举办第三世界国家防灾减灾国际培训班,日本政府通过日本国际合作事业团体(JICA)东京和曼谷办事处作了前期工作。199...  相似文献   

11.
Southern California is an increasingly urbanized hotspot for surfing, thus it is of great interest to assess the human illness risks associated with this popular ocean recreational water sport from exposure to fecal bacteria contaminated coastal waters. Quantitative microbial risk assessments were applied to eight popular Southern California beaches using readily available enterococcus and fecal coliform data and dose-response models to compare health risks associated with surfing during dry weather and storm conditions. The results showed that the level of gastrointestinal illness risks from surfing post-storm events was elevated, with the probability of exceeding the US EPA health risk guideline up to 28% of the time. The surfing risk was also elevated in comparison with swimming at the same beach due to ingestion of greater volume of water. The study suggests that refinement of dose-response model, improving monitoring practice and better surfer behavior surveillance will improve the risk estimation.  相似文献   

12.
Cost-effective network design for groundwater flow monitoring   总被引:1,自引:0,他引:1  
The extensive use of groundwater resources has increased the need for developing cost-effective monitoring networks to provide an indication of the degree to which the subsurface environment has been affected by human activities. This study presents a cost-effective approach to the design of groundwater flow monitoring networks. The groundwater network design is formulated with two problem formats: maximizing the statistical monitoring power for specified budget constraint and minimizing monitoring cost for statistical power requirement. The statistical monitoring power constraint is introduced with an information reliability threshold value. A branch and bound technique is employed to select the optimal solution from a discrete set of possible network alternatives. The method is tested to the design of groundwater flow monitoring problem in the Pomona County, California.  相似文献   

13.
A joint effort between the Connecticut Department of Transportation and the University of Connecticut has been underway for more than 20 years to utilize various structural monitoring approaches to assess different bridges in Connecticut. This has been done to determine the performance of existing bridges, refine techniques needed to evaluate different bridge components, and develop approaches that can be used to provide a continuous status of a bridge's structural integrity. This paper briefly introduces the background of these studies, with emphasis on recent research and the development of structural health monitoring concepts. This paper presents the results from three different bridge types: a post-tensioned curved concrete box girder bridge, a curved steel box-girder bridge, and a steel multi-girder bridge. The structural health monitoring approaches to be discussed have been successfully tested using field data collected during multi-year monitoring periods, and are based on vibrations, rotations and strains. The goal has been to develop cost-effective strategies to provide critical information needed to manage the State of Connecticut's bridge infrastructure.  相似文献   

14.
Entanglement records of hauled out pinnipeds are useful for monitoring trends in impacts of synthetic materials, a principal contaminant, upon pinniped populations. This report documents entanglement of five species (California Sea Lions, Northern Elephant Seals, Steller Sea Lions, Pacific Harbor Seals, and Northern Fur Seals) at South-east Farallon Island (SEFI), an island in Northern California, 1976–1998, when a total of 914 pinnipeds were observed entangled in or with body constrictions from synthetic material. There was a significant decrease in entangled Northern Elephant Seals over the study period. Of the 27 Steller Sea Lions observed entangled, 37% were adult Steller Sea Lions entangled in salmon fishing gear. This report highlights an ongoing problem of entanglement of pinnipeds in synthetic materials in Northern California.  相似文献   

15.
在医院、教学楼等建筑中广泛采用隔震技术,能降低地震对上部结构的破坏作用。虽然隔震技术经过几十年的发展已趋于成熟,但环境及其他荷载对隔震结构性能的影响规律、结构设计的合理性以及震后结构状态评估等问题,仍需建立隔震结构健康监测系统对施工、运营期的结构响应进行监测,并对其进行评估与验证。首先,针对基础隔震结构的特点,研究了基础隔震结构的主要监测内容;在此基础上提出基础隔震结构健康监测系统的总体设计要求及原则,根据不同监测对象(整体与局部监测量)给出基础隔震结构传感器布置原则和数据采集系统软硬件设计原则,提出基础隔震结构设计验证与安全评定方法;最后给出基础隔震结构健康监测值得进一步研究的问题。  相似文献   

16.
—?We present an earthquake location algorithm, the Broadband Waveform Regional Earthquake Location Program (BW_RELP), which utilizes phase onset times and wave azimuths recorded by three-component broadband seismic stations and an adaptive migrating grid search algorithm to find the global minimum in an arbitrary normed misfit parameter. The performance of BW_RELP is demonstrated using regional (300–800?km distant) broadband recordings to locate events in the 1995 Ridgecrest, California earthquake sequence. The purpose of this study is to introduce the BW_RELP algorithm in detail and to expand on the previous paper by Deger et?al. (BSSA, 88, 1353–1362, 1998), using one Berkeley Digital Seismic Network (BDSN) station (YBH) and two USNSN stations (ELK and MNV) which span 300–800?km in distance and 55 degrees in azimuth, to further investigate the capability of a sparse broadband network of three-component stations at monitoring a region located outside of the network, as will be the case in the monitoring of the Comprehensive Test-Ban-Treaty (CTBT) for low magnitude seismic events. We assess the capability of this sparse three-station broadband network and we compare locations estimated from phase onset time and wave azimuth measurements to a ground-truth catalog of high-quality earthquake locations derived from data recorded by the Southern California Seismic Network (SCSN). The results indicate that in the regional distance range it is possible, when an appropriate calibration event is available, to obtain absolute event locations to within 18?km as is prescribed by the CTBT.  相似文献   

17.
Highly industrialized areas, such as the Southern California Bight, often have high levels of contaminants in marine sediments, which can cause chronic exposure to organisms long after their use has ceased. tDDT and tPCB were analyzed in the blubber of 145 stranded pinnipeds that died at local marine mammal centers between 1994 and 2006. Resident species (California sea lion and Pacific harbor seal) had significantly higher concentrations of tDDT and tPCB than the transient species (northern elephant seal). Adult female California sea lions had significantly lower concentrations of tDDT and tPCB than pups, yearlings, and adult males. Concentrations of both tDDT and tPCB in California sea lions significantly declined over time, but did not change in northern elephant seals. Current concentrations of tDDT and tPCB in California sea lions and harbor seals are among the highest values reported worldwide for marine mammals and exceed those reported to cause adverse health effects.  相似文献   

18.
Fragility functions are commonly used in performance‐based earthquake engineering for predicting the damage state of a structure subjected to an earthquake. This process often involves estimating the structural damage as a function of structural response, such as the story drift ratio and the peak floor absolute acceleration. In this paper, a new framework is proposed to develop fragility functions to be used as a damage classification/prediction method for steel structures based on a wavelet‐based damage sensitive feature (DSF). DSFs are often used in structural health monitoring as an indicator of the damage state of the structure, and they are easily estimated from recorded structural responses. The proposed framework for damage classification of steel structures subjected to earthquakes is demonstrated and validated with a set of numerically simulated data for a four‐story steel moment‐resisting frame designed based on current seismic provisions. It is shown that the damage state of the frame is predicted with less variance using the fragility functions derived from the wavelet‐based DSF than it is with fragility functions derived from an alternate acceleration‐based measure, the spectral acceleration at the first mode period of the structure. Therefore, the fragility functions derived from the wavelet‐based DSF can be used as a probabilistic damage classification model in the field of structural health monitoring and an alternative damage prediction model in the field of performance‐based earthquake engineering. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

19.
The concept of health monitoring is a key aspect of the field of medicine that has been practiced for a long time. A commonly used diagnostic and health monitoring practice is pulse diagnosis, which can be traced back approximately five thousand years in the recorded history of China. With advances in the development of modem technology, the concept of health monitoring of a variety of engineering structures in several applications has begun to attract widespread attention. Of particular interest in this study is the health monitoring of civil structures. It seems natural, and even beneficial, that these two health-monitoring methods, one as applies to the human body and the other to civil structures, should be analyzed and compared. In this paper, the basic concepts and theories of the two monitoring methods are first discussed. Similarities are then summarized and commented upon. It is hoped that this correlation analysis may help provide structural engineers with some insights into the intrinsic concept of using pulse diagnosis in human health monitoring, which may be of some benefit in the development of modem structural health monitoring methods.  相似文献   

20.
To establish an experimental, practical and open scientific experimental platform for earthquake monitoring and prediction, with reference to that of the southern California earthquake center(SCEC), China Earthquake Administration initiated a project for an experimental field in Sichuan and Yunnan Province in 2014. The chosen area is a seismically active region in the southeastern margin of the Tibetan plateau. A series of work compiling basic maps have been launched to collect fundamental data of this area including geologic structure, earthquake geology, geophysics, geodesy, and geochemistry. The map of earthquake surface ruptures in this region is one of these basic maps. This paper presents the compilation of this map. It includes earthquake epicenters, earthquake surface ruptures, faults, strata, magmatic rocks, and geographical data. This work summarized 87 destructive earthquakes, and 22 earthquake surface rupture zones, and analyzed the distribution characterization of earthquake epicenters, strata and magmatic rocks. The content in the map is reliable and integrated. This work will provide reliable earthquake-geology data for establishing geodynamics models and other future research of the national experimental field of earthquake monitoring and prediction in Sichuan and Yunnan Province.  相似文献   

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