共查询到20条相似文献，搜索用时 40 毫秒
1.
Shandong province is located on the east coast of China and has a coastline of about 3100 km. There are only a few tsunami events recorded in the history of Shandong Province, but the tsunami hazard assessment is still necessary as the rapid economic development and increasing population of this area. The objective of this study was to evaluate the potential danger posed by tsunamis for Shandong Province. The numerical simulation method was adopted to assess the tsunami hazard for coastal areas of Shandong Province. The Cornell multi-grid coupled tsunami numerical model (COMCOT) was used and its efficacy was verified by comparison with three historical tsunami events. The simulated maximum tsunami wave height agreed well with the observational data. Based on previous studies and statistical analyses, multiple earthquake scenarios in eight seismic zones were designed, the magnitudes of which were set as the potential maximum values. Then, the tsunamis they induced were simulated using the COMCOT model to investigate their impact on the coastal areas of Shandong Province. The numerical results showed that the maximum tsunami wave height, which was caused by the earthquake scenario located in the sea area of the Mariana Islands, could reach up to 1.39 m off the eastern coast of Weihai city. The tsunamis from the seismic zones of the Bohai Sea, Okinawa Trough, and Manila Trench could also reach heights of >1 m in some areas, meaning that earthquakes in these zones should not be ignored. The inundation hazard was distributed primarily in some northern coastal areas near Yantai and southeastern coastal areas of Shandong Peninsula. When considering both the magnitude and arrival time of tsunamis, it is suggested that greater attention be paid to earthquakes that occur in the Bohai Sea. In conclusion, the tsunami hazard facing the coastal area of Shandong Province is not very serious; however, disasters could occur if such events coincided with spring tides or other extreme oceanic conditions. The results of this study will be useful for the design of coastal engineering projects and the establishment of a tsunami warning system for Shandong Province. 相似文献
2.
Peitao Wang Zhiyuan Ren Lining Sun Jingming Hou Zongchen Wang Ye Yuan Fujiang Yu 《海洋学报(英文版)》2021,40(11):11-30
The systematic discrepancies in both tsunami arrival time and leading negative phase (LNP) were identified for the recent transoceanic tsunami on 16 September 2015 in Illapel, Chile by examining the wave characteristics from the tsunami records at 21 Deep-ocean Assessment and Reporting of Tsunami (DART) sites and 29 coastal tide gauge stations. The results revealed systematic travel time delay of as much as 22 min (approximately 1.7％ of the total travel time) relative to the simulated long waves from the 2015 Chilean tsunami. The delay discrepancy was found to increase with travel time. It was difficult to identify the LNP from the near-shore observation system due to the strong background noise, but the initial negative phase feature became more obvious as the tsunami propagated away from the source area in the deep ocean. We determined that the LNP for the Chilean tsunami had an average duration of 33 min, which was close to the dominant period of the tsunami source. Most of the amplitude ratios to the first elevation phase were approximately 40％, with the largest equivalent to the first positive phase amplitude. We performed numerical analyses by applying the corrected long wave model, which accounted for the effects of seawater density stratification due to compressibility, self-attraction and loading (SAL) of the earth, and wave dispersion compared with observed tsunami waveforms. We attempted to accurately calculate the arrival time and LNP, and to understand how much of a role the physical mechanism played in the discrepancies for the moderate transoceanic tsunami event. The mainly focus of the study is to quantitatively evaluate the contribution of each secondary physical effect to the systematic discrepancies using the corrected shallow water model. Taking all of these effects into consideration, our results demonstrated good agreement between the observed and simulated waveforms. We can conclude that the corrected shallow water model can reduce the tsunami propagation speed and reproduce the LNP, which is observed for tsunamis that have propagated over long distances frequently. The travel time delay between the observed and corrected simulated waveforms is reduced to <8 min and the amplitude discrepancy between them was also markedly diminished. The incorporated effects amounted to approximately 78％ of the travel time delay correction, with seawater density stratification, SAL, and Boussinesq dispersion contributing approximately 39％, 21％, and 18％, respectively. The simulated results showed that the elastic loading and Boussinesq dispersion not only affected travel time but also changed the simulated waveforms for this event. In contrast, the seawater stratification only reduced the tsunami speed, whereas the earth's elasticity loading was responsible for LNP due to the depression of the seafloor surrounding additional tsunami loading at far-field stations. This study revealed that the traditional shallow water model has inherent defects in estimating tsunami arrival, and the leading negative phase of a tsunami is a typical recognizable feature of a moderately strong transoceanic tsunami. These results also support previous theory and can help to explain the observed discrepancies. 相似文献
3.
S. F. Dotsenko 《Physical Oceanography》2005,15(6):363-369
We perform the numerical analysis of the propagation of tsunamis in the Black Sea from the zones of seismic generation located
to the south of the Crimea and in the northwest part of the sea. It is shown that the tsunamis induced by earthquakes in the
Crimean seismic zone are entrapped by the nearest part of the shelf and do not result in noticeable oscillations of level
in the northwest part of the sea. This enables us to explain the absence of manifestations of tsunamis in 1927, 1939, and
1966 near Odessa. The tsunami waves generated by earthquakes in the northwest part of the sea are characterized by the directivity
of their propagation. The wave height is maximum in the areas corresponding to the north and east directions of propagation.
Hence, the north coast of the sea and the Kalamit Bay (Crimean Peninsula) are characterized by elevated tsunami hazard for
earthquakes occurring in the northwest part of the Black Sea.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 46–53, November–December, 2005. 相似文献
4.
The catastrophic tsunami of December 26, 2004 in Southeast Asia revealed the necessity of creating tsunami early warning systems
in the regions of the World Ocean where these systems are still absent but the potential hazard of tsunami generation exists.
The Black Sea is one of these regions. We present the general characteristic of the tsunami hazard in the Black-Sea region
and describe the most probable zones of tsunami generation, the specific features of tsunami propagation, and the parameters
of tsunamis according to the data of observations and the results of numerical simulations. We also discuss the possibility
of tsunami early warning on the basis of the operative data provided by the network of hydrometeorological and seismological
observation stations existing in this region.
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 57–66, September–October, 2008. 相似文献
5.
This paper describes the geotectonics of the Caspian Sea basin and the seismicity of its central part. The seismicity analysis enables us to identify the most probable zones of tsunami generation. We also present a brief review of the historical records of tsunamis in the Caspian Sea. In order to estimate the tsunami risk, we used the method of numerical hydrodynamic simulation while taking into account the real topography of the Caspian Sea. The computation of the wave field for the possible tsunamis occurring in the central part of the Caspian Sea allowed us to estimate the maximum expected heights of the waves along the coast of the CIS countries (Russia, Azerbaijan, Kazakhstan, and Turkmenistan). On the basis of the earthquake statistics in the region and the results of numerical experiments, we show that the extreme wave heights can reach 10 m at certain parts of the coast. Such extreme events correspond to extended (up to 200 km) seismic sources with M S ～ 8 and a recurrence period of T ≈ 1600 years. The tsunami wave heights are expected to be as high as 3 m for sources of lesser extent (<50 km) with earthquake magnitudes of M S ～ 7 and a recurrence period of 200 years. 相似文献
6.
Stefano Tinti 《Marine Geodesy》2013,36(3-4):243-254
Abstract In the Mediterranean Sea, tsunamigenic sources may be found in several areas in the belt running from Gibraltar up to the Black Sea, but they are concentrated mainly around Italy and Greece. Most of the sources are located close to the coasts and excite tsunamis reaching the coasts soon after the generation time. Tsunami research and tsunami mitigation programs are only in a very initial stage in the Mediterranean area. The present activities are focused chiefly to tsunami potential evaluation and on tsunami propagation modeling. The establishment of efficient observational networks, centers for data management and services, and systems for issuing tsunami warnings are some of the most urgent needs. In this context, the envisaged contribution of marine geodesy is twofold. First, monitoring of submarine active faults and submarine volcanic areas by means of systems capable of detecting seafloor deformation may contribute in identifying periods in which the probability of tsunami generation increases beyond a threshold value, especially in those tsunamigenic zones where geodetic observations on land are insufficient (for example, eastern Sicily in Italy and the Hellenic Arc in southern Greece). Second, since most of the active sources are close to the coastline, computations of tsunami propagation and run‐up may be significantly enhanced by a better knowledge of the bathymetry of the seabelt facing the coasts. 相似文献
7.
The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea. 相似文献
8.
越洋海啸的数值模拟及其对我国的影响分析 总被引：7，自引：2，他引：5
简要介绍了地震海啸产生的物理机制、海啸波在大洋中的传播特性以及海啸所具有的超强破坏力可能引发的巨大灾害;概述了全球地震海啸发生的频率和太平洋区域历史海啸的时空分布;整理分析了我国沿海发生海啸的频次和空间分布。针对越洋海啸传播的特点,采用基于波浪追逐原理和自适应网格加密技术的海啸数值模型对1960智利海啸进行了数值模拟,将模拟的结果与历史记录进行了对比,验证了模型的可靠性。通过对数值模拟结果的分析,初步讨论了我国沿海地区越洋海啸的危险性,并定量阐述了越洋海啸对我国各海区的影响。 相似文献
9.
Amr Z. Hamouda 《Marine Geophysical Researches》2010,31(3):197-214
Scenarios of tsunami effects represent a very useful technique for the definition and evaluation of tsunami hazard and risk
for the Egyptian coast. This paper is an attempt to develop different worst scenarios of tsunamigenesis toward the Egyptian
Coast for five segment localities along three different sub-regions (Hellenic Arc, Cyprean Arc and Levantine Coast) in the
eastern Mediterranean Sea. These segments are the southwest Hellenic Arc, southeast Hellenic Arc, northeast Hellenic Arc,
west of Cyprean Arc and Levantine. For each of them, the scenario takes into account a seismic fault capable of generating
an earthquake with magnitude equal to or larger than the highest magnitude registered in that region in historical times.
Then the ensuing tsunamis are simulated numerically, highlighting the basic features of the wave propagation and roughly identifying
the coastal sectors that are expected to suffer the heaviest tsunami effects. The output data indicated that the first wave
of tsunamis from different segments attacked the nearest reference localities (city located nearest each segment) along the
Egyptian shore between 28 and 50 min after an earthquake. Tsunamis from these earthquake scenarios produced maximum run-up
heights ranging from 1.7 to 9.4 m at the shore. A Beirut Thrust scenario (Levantine segment) included the fact that only a
small portion of the fault extended out into the sea, leading to a small effective tsunami source area. In contrast, the southwest
Hellenic Arc segment (as in the A.D. 365 earthquake) has high displacement (15 m) and a long extensional fault, forming a
highly effective tsunami source area. 相似文献
10.
本文基于有限断层模型和OKADA 位错模型计算海表变形场作为初始条件，利用MOST 海啸数值模型模拟分析了2010年智利和2011 年日本地震海啸在我国东南沿海地区的海啸传播特征，海啸波模拟结果与观测数据吻合较好。重点研究分析了沈家门港口海域的海啸波流特征及其诱导的涡旋结构。研究结果表明：尽管两次事件的海啸源位置及破裂特征完全不同，但海啸波流在我国东南沿岸的分布特征大致相似；另外相对于海啸波幅而言，港湾中海啸流具有更强的空间差异性，港口入口、岬角地形处和岛屿间水道中往往会有强流存在。尽管这两次越洋海啸均未能在我国东南沿海引发淹没情形，但通过数值计算发现局部均存在超过3 m/s 以上的强流，因此进行海啸预警及风险管理时应综合考虑海啸波流的影响。 相似文献
11.
G. V. Shevchenko T. N. Ivelskaya A. V. Loskutov 《Izvestiya Atmospheric and Oceanic Physics》2014,50(5):459-473
We describe the progress (since 2008) in the development of the network of autonomous bottom stations of the Institute of Marine Geology and Geophysics, Far East Branch, Russian Academy of Sciences (IMGG FEB RAS), and telemetry recorders of the Tsunami Warning Service (TWS) on the Pacific coast of Russia. We show that these instrumental measurements are important for operational tsunami warning and performing an a posteriori study of tsunami manifestation features. The characteristics of the Samoan (2009), Chilean (2010), and Tohoku (2011) tsunamis in different areas of the Russian Far East coast are examined. 相似文献
12.
Narumi Takahashi Yasuhisa Ishihara Hiroshi Ochi Tatsuya Fukuda Jun’ichiro Tahara Yosaku Maeda Motoyuki Kido Yusaku Ohta Katsuhiko Mutoh Gosei Hashimoto Satoshi Kogure Yoshiyuki Kaneda 《Marine Geophysical Researches》2014,35(3):243-253
We have developed a new system for real-time observation of tsunamis and crustal deformation using a seafloor pressure sensor, an array of seafloor transponders and a Precise Point Positioning (PPP ) system on a buoy. The seafloor pressure sensor and the PPP system detect tsunamis, and the pressure sensor and the transponder array measure crustal deformation. The system is designed to be capable of detecting tsunami and vertical crustal deformation of ±8 m with a resolution of less than 5 mm. A noteworthy innovation in our system is its resistance to disturbance by strong ocean currents. Seismogenic zones near Japan lie in areas of strong currents like the Kuroshio, which reaches speeds of approximately 5.5 kt (2.8 m/s) around the Nankai Trough. Our techniques include slack mooring and new acoustic transmission methods using double pulses for sending tsunami data. The slack ratio can be specified for the environment of the deployment location. We can adjust slack ratios, rope lengths, anchor weights and buoy sizes to control the ability of the buoy system to maintain freeboard. The measured pressure data is converted to time difference of a double pulse and this simple method is effective to save battery to transmit data. The time difference of the double pulse has error due to move of the buoy and fluctuation of the seawater environment. We set a wire-end station 1,000 m beneath the buoy to minimize the error. The crustal deformation data is measured by acoustic ranging between the buoy and six transponders on the seafloor. All pressure and crustal deformation data are sent to land station in real-time using iridium communication. 相似文献
13.
Tsunamis associated with the 2011 off the Pacific Coast of Tohoku Earthquake seriously disrupted the shallow marine ecosystem along a 2000 km stretch of the Pacific coast of Japan. The effects of the 2011 tsunamis on the soft-bottom benthic community have been relatively well studied in the intertidal zone, whereas tsunami effects on the subtidal benthos remain poorly understood. Here, we investigated populations of the world’s largest spoon worm Ikeda taenioides (Annelida: Echiura: Ikedidae) in subtidal zone of Funakoshi Bay, Tohoku District, northeastern Japan. Subtidal scuba-diving surveys at two sites in the bay showed extremely long proboscises frequently extending from small holes in the sandy seafloor shortly before and soon after the tsunami disturbances. Based on morphological and molecular identification, the proboscises were revealed to be parts of I. taenioides. On 30 November 2011, 265 days after the tsunami event, many large-sized individuals with >1 m long proboscises were observed; these individuals were probably not derived from post-tsunami larval recruitment but more likely survived the tsunami disturbances. This is surprising because other sympatric megabenthos (e.g. spatangoid echinoids and venerid bivalves) and seagrass beds were almost completely destroyed (although they later recovered) by the tsunamis in this bay. The burrows of I. taenioides are known to be very deep (70–90 cm), which may have sheltered them from the impacts of the tsunamis. Our observations suggest that the effects of the 2011 tsunamis on benthos in soft sediments may differ depending on their burrowing depth. 相似文献
14.
植被斜坡岸滩海啸波消减数值模拟研究 总被引：1，自引：0，他引：1
An explicit one-dimensional model based on the shallow water equations(SWEs) was established in this work to simulate tsunami wave propagation on a vegetated beach. This model adopted the finite-volume method(FVM)for maintaining the mass balance of these equations. The resistance force caused by vegetation was taken into account as a source term in the momentum equation. The Harten–Lax–van Leer(HLL) approximate Riemann solver was applied to evaluate the interface fluxes for tracing the wet/dry transition boundary. This proposed model was used to simulate solitary wave run-up and long-periodic wave propagation on a sloping beach. The calibration process suitably compared the calculated results with the measured data. The tsunami waves were also simulated to discuss the water depth, tsunami force, as well as the current speed in absence of and in presence of forest domain. The results indicated that forest growth at the beach reduced wave energy loss caused by tsunamis. A series of sensitivity analyses were conducted with respect to variable parameters(such as vegetation densities, wave heights, wave periods, bed resistance, and beach slopes) to identify important influences on mitigating tsunami damage on coastal forest beach. 相似文献
15.
16.
The numerical analysis of the evolution of tsunamis is performed for the Sea of Azov. Our calculations are carried out on
a grid with steps of 500 m, as applied to seaquakes with magnitudes within the range 6–7 for 18 circular zones of generation
covering almost the entire water area of the sea. It is shown that the oscillations of the sea level in the form of cellular
waves are formed as a result of the wave reflections from the coasts. Small areas of the elevated activity of waves are formed
in the zones of irregularity of the coastline on the north coast of the sea and in the zones of shoals in the southeast part
of the basin. On the basis of the determined values of extreme elevations and lowerings of the sea level, we can make a conclusion
that the tsunami hazard is quite low for the coast of the Sea of Azov. 相似文献
17.
A study of tsunami events in the East （Japan） Sea using continuous Galerkin finite element model, aiming at reproducing tsunami waves generated by underwater earthquakes in 1983 and 1993 respectively has been performed focusing on the geographic extent of a topographic feature in the East （Japan） Sea. Numerical models can be the proper tools to study the combined effects of realistic topography. Subsequently, using the FEM based two-dimensional model we have simulated the smoothed and flattened topographic effects by removal of Yamato Rise and seamounts for the cases of tthe 1983 Central region earthquake tsunami and the 1993 southwestern Hokkaido earthquake tsunami. The results have shown that there will be higher tsunamis along the eastern coasts of Korea in general except some areas, like Sokcho with removal of topographic highs, thus providing complicated bottom topography of the East （Japan） Sea as effective tsunami energy scattering. 相似文献
18.
E. A. Rogozhin 《Izvestiya Atmospheric and Oceanic Physics》2016,52(7):683-696
The results of geological and geomorphological investigations have shown that the South China Sea and its close coastal margins are in danger because of the possibility of a tsunami arriving from seismically active zones in the Philippines and Taiwan to the west and northwest coastal zones of the South China Sea. The collected data on paleotsunamis make it possible to date at least three such ancient catastrophes that have occurred in the last 1000 years (about 350, 650, and 960 years ago). The height of splashes of these ancient tsunami waves can be estimated. It was more than 7 m and in some places exceeded 15 m. The length of the sea coast covered by the paleotsunamis is estimated at several hundred (up to a first thousand) kilometers, which gives the opportunity to distinguish them from the ancient typhoons that are also typical of the region. 相似文献
19.
We perform the numerical analysis of the process of propagation of long waves in the northwest part of the Black Sea and consider
ten possible zones of the seismic generation of tsunamis. The numerical analysis is performed on a grid with steps of 500 m.
It is shown that the location of the tsunami source significantly affects the distribution of the heights of waves along the
coast. As a rule, the most intense waves are formed in the closest part of the coast. The earthquakes in the South-Coast seismic
zone do not lead to the formation of tsunamis in the west part of the sea. Only strong earthquakes in the northwest part of
the sea can be responsible for noticeable oscillations of the Black-Sea level. The period of tsunamis near Odessa is close
to 1 h and depends on the magnitude of the earthquake. In the region of Sevastopol, this period is 2--3 times smaller. In
the major part of the coastal points, the extreme elevations and lowerings of the sea level do not exceed (in modulus) the
initial displacements of the sea surface at the source of tsunamis. An intensification of waves emitted from the zones of
generation located in the deeper part of the investigated region was observed for some parts of the Romanian coast and the
west coast of Crimea. As the magnitude of the earthquake increases, the intensification of waves near the coast becomes more
pronounced. 相似文献
20.
T. S. Murty 《Marine Geodesy》2013,36(1):73-102
The dynamics of tsunamis can be divided, for convenience, into three parts: tsunami generation, tsunami propagation, and the coastal problems. Out of these three, the problem of tsunami propagation is probably better understood than the other two. One of the main hindrances to the quantitative prediction of tsunami amplitudes at various coastal locations is a lack of detailed knowledge about the deep water signature of a tsunami. Here, the present understanding of this problem is discussed. 相似文献