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南海东南边缘的马尼拉海沟是国际上公认具有发生破坏性地震海啸条件的危险地区,由于南海没有大面积的岛屿阻隔海啸传播,如果在马尼拉海沟发生大地震引发海啸,那么将对广东省漫长的海岸线造成严重破坏。广东省南海地震海啸监测预警系统建设在广东省地震速报系统和国家地震自动速报备份系统的基础上,由地震速报、震源机制快速计算、海啸数值模拟计算等模块组成,对南海地震海啸进行实时监测,提供海啸波浪到达海岸线的估计时刻和最大海浪高度,提供预警信息等社会公共服务。 相似文献
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海啸传播模型与数值模拟研究进展 总被引:1,自引:0,他引:1
海啸在浅水大陆架的传播问题由于其非线性作用和浅水效应而变得十分复杂,然而目前成熟的海啸传播理论及数值模拟结果在这方面与实际并不一致.本文比较分析了可用来模拟大陆架海啸传播的浅水波模型和数值方法,并提出对我国东海陆架边缘可能发生的近海海啸需要开展数值试验研究. 相似文献
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海啸灾害及其预警系统 总被引:13,自引:0,他引:13
地震海啸是最严重的自然灾害之一。2004年底印度洋大海啸更是震撼了全世界。本文对海啸的定义、性质、特征,历史上和近代的中国和世界的严重海啸灾害作了简单介绍。指出建立和完善海啸预警系统,可以在一旦海啸发生后,争取几十分钟甚至几小时时间,提前发出海啸警报信息,这就能极大地减轻海啸灾害。本文简单地介绍了海啸预警系统的主要内容。 相似文献
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北京时间2011年3月11日13时46分(05:46 UTC)日本东北部近海(38.3°N,142.4°E)发生Mw9.0级特大地震,此次地震的强度为日本近1200a来最强.随后环太平洋的数十个国家和地区的验潮站和海啸监测浮标均监测到了强震引发的越洋海啸,海啸奔袭23 h到达南美洲的智利沿岸;此次海啸除了对近场的日本东北部沿岸地区造成了巨大灾害,还对太平洋东岸的部分国家和地区造成了一定程度的影响.地震发生4 h后海啸波到达我国台湾东部沿海,6~8 h海啸波到达我国大陆东南沿海,受此影响我国发布了第一份海啸蓝色警报.本文利用海啸数值模型对此次地震海啸的产生、越洋传播过程进行了数值模拟,给出了海啸波能量在我国近海及泛太平洋区域分布特征;同时重点模拟分析了海啸波在日本及中国近海传播的波动特征,模拟结果与观测数据吻合良好.最后通过对数值模拟结果的分析,阐述了此次海啸对中国的影响,给出了潜在的日本地震海啸对中国的风险估计. 相似文献
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准确预估南海海啸风险是有效防灾减灾的前提.前人一般把弹性半无限空间背景下解算出来的海底位错直接等同于初始海啸分布,继而开展海啸传播过程研究.由于断层破裂并非瞬时完成,破裂过程会导致初始海啸波高小于海底位错量,即初始海啸衰减.本文基于高精度地形和高密度网格,求解非线性浅水方程,分别针对马尼拉断裂带的南段、中段和北段,构建南海海啸传播数值模型,试图定量考察初始海啸衰减作用对南海海啸的影响.模拟结果表明一定幅度的初始波高衰减将导致几乎相同幅度的海啸波高衰减,相应的偏差可以忽略.在保守的初始海啸衰减幅度(10%)下,模拟结果显示我国东南沿海、越南东部沿海和巴拉望岛为海啸危险区.另外,模型显示科里奥利力导致的波高变化幅度小于5 cm且其分布样式符合预期,这进一步佐证了数值模型的可靠性,也表明在实际南海海啸模拟中可以忽略科里奥利力进而提高计算效率.结合前人的沉积学认识和本文的数值模拟结果,本文认为南澳岛、西沙东岛和越南绥和周边曾同时遭受海啸侵袭,产生海啸的断裂带最有可能是马尼拉断裂带南段.后续有必要加强南澳岛、西沙东岛和越南东部的沉积学研究,识别更早的海啸事件,以期有力约束南海下次海啸事件的发生年... 相似文献
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Effects of bathymetry on tsunami propagation: Application of ray tracing to tsunamis 总被引:4,自引:0,他引:4
Kenji Satake 《Pure and Applied Geophysics》1988,126(1):27-36
Ray tracing of seismic surface waves is applied to tsunami propagation to examine bathymetric effect along its propagation path. Computations are made for trans-Pacific tsunamis and for near-field tsunamis in the Japan Sea. For tsunamis across the Pacific Ocean, the comparison to a uniform ocean shows that focusing and defocusing, due to bathymetry, are significant for some combinations of source and receiver. For example, the refraction of rays is predominant at the East Pacific Rise for the tsunami from Chile. The tsunamis in the Japan Sea are strongly affected by the shallow Yamato Rise. The predicted arrival time and amplitude distribution generally agree with the observations from an actual tsunami. Since the computation can be made very quickly, the method is useful for preliminary analysis of tsunami propagation, such as in an operational warning system or in the determination of computational area for finite-difference computation. 相似文献
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我国地震海啸危险性分析方法研究 总被引:4,自引:0,他引:4
美国、日本等国家已经建立了完善的海啸防灾减灾机制,对海啸危险性分析方法的研究也做了很多的工作,而我国目前在这方面尚属空白。本文首次对我国的海啸危险性分析方法进行了研究,提出了我国地震海啸危险性分析的基本原则,在此基础上,借鉴我国成熟的地震危险性分析方法,建立了我国地震海啸危险性分析方法的主要步骤。在根据我国一些历史地震海啸资料的基础上,通过统计的方法对我国珠江三角洲的海啸危险性进行了研究。 相似文献
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地震海啸监测预警现状与进展 总被引:3,自引:2,他引:1
2004年12月26日印度洋地震大海啸引起了全世界公众的关注和政府的重视,如何预防地震海啸造成的灾害,建立有效的预警机制,成为政府和社会关注的话题。介绍了国内外地震海啸监测预警的历史、现状与当前的发展方向。 相似文献
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Armin Freundt Wilfried Strauch Steffen Kutterolf Hans-Ulrich Schmincke 《Pure and Applied Geophysics》2007,164(2-3):527-545
This paper emphasizes the fact that tsunamis can occur in continental lakes and focuses on tsunami triggering by processes
related to volcanic eruptions and instability of volcanic edifices. The two large lakes of Nicaragua, Lake Managua and Lake
Nicaragua, host a section of the Central American Volcanic Arc including several active volcanoes. One case of a tsunami in
Lake Managua triggered by an explosive volcanic eruption is documented in the geologic record. However, a number of events
occurred in the past at both lakes which were probably tsunamigenic. These include massive intrusion of pyroclastic flows
from Apoyo volcano as well as of flank-collapse avalanches from Mombacho volcano into Lake Nicaragua. Maar-forming phreatomagmatic
eruptions, which repeatedly occurred in Lake Managua, are highly explosive phenomena able to create hugh water waves as was
observed elsewhere. The shallow water depth of the Nicaraguan lakes is discussed as the major limiting factor of tsunami amplitude
and propagation speed. The very low-profile shores facilitate substantial in-land flooding even of relatively small waves.
Implications for conceiving a possible warning system are also discussed. 相似文献
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Preliminary numerical simulation of potential earthquake-induced tsunami in East China Sea 总被引:1,自引:0,他引:1
In this paper,we present a numerical simulation of the propagation of a tsunami in the East China Sea,which might be induced by a hypothetical M8.5 earthquake in Okinawa Trough. Our results show that the initial maxi-mum wave height of tsunami could reach as high as 4.3 m for the hypothetical earthquake. It would take 3.5~4 hours for the tsunami to propagate to the coast of Zhejiang Province,and 7~8 hours to the near-shore of Shanghai. The peak tsunami height could be up to about 2 m in the coast of Zhejiang Province. Based on the numerical ex-periments,we plot the arrival time contours of tsunami in East China Sea and time history curves on the three ob-servational stations,and discussed the significance of the pre-analysis. 相似文献