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1.
Tide gauge data collected from Sri Lanka (three stations) and Western Australia (eleven stations) during the Indian Ocean tsunamis, which occurred in December 2004, March 2005, July 2006, and September 2007, and incorporated five tsunamis, were examined to determine tsunami behaviour during these events. During the December 2004 tsunami, maximum wave heights of 3.87 m and 1.75 m were recorded at Colombo (Sri Lanka) and Bunbury (Western Australia), respectively. The results indicated that although the relative magnitudes of the tsunamis varied, the tsunami behaviour at each station was similar. This was due to the effect of the local and regional topography. At all tide gauges, the spectral energy corresponding to periods between 20 and 85 minutes increased during the tsunami. The sea-level data obtained from the west and south coasts of Sri Lanka (Colombo and Kirinda) indicated the importance of wave reflections from the Maldives Island chain, which produced the maximum wave two to three hours after the arrival of the first wave. In contrast, Trincomalee on the east coast did not show evidence of a reflected wave. Similarly, along the west coast of Australia, the highest waves occurred 15 hours after the arrival of the first wave. Here, based on travel times, we postulated that the waves were reflected from the Mascarene Ridge and/or the Island of Madagascar. Reflected waves were not present in the 2006 tsunami, where the primary waves propagated away from topographic features. One of the main influences of the tsunami was to set up oscillations at the local resonance frequency. Because Sri Lanka and Western Australia have relatively straight coastlines, these oscillations were related to the fundamental period of the shelf oscillation. For Colombo, this corresponded to 75-minute period, whereas in Geraldton and Busselton (Australia), the four-hour period was most prominent; at Jurien Bay and Fremantle, the resonance period was 2.7 hours. 相似文献
2.
On December 26, 2004, the earthquake off the southern coast of Sumatra in the Indian Ocean generated far-reaching tsunami waves, resulting in severe disruption of the coastal aquifers in many countries of the region. The objective of this study was to examine the impact of the tsunami on groundwater in coastal areas. Field investigations on the east coast of Sri Lanka were carried out along a transect located perpendicular to the coastline on a 2.4 km wide sand stretch bounded by the sea and a lagoon. Measurements of groundwater table elevation and electrical conductivity (EC) of the groundwater were carried out monthly from October 2005 to August 2007. The aquifer system and tsunami saltwater intrusion were modeled using the variable-density flow and solute transport code HST3D to understand the tsunami plume behavior and estimate the aquifer recovery time. EC values reduced as a result of the monsoonal rainfall following the tsunami with a decline in reduction rate during the dry season. The upper part of the saturated zone (down to 2.5 m) returned to freshwater conditions (EC < 1000 μS/cm) 1 to 1.5 years after the tsunami, according to field observations. On the basis of model simulations, it may take more than 15 years for the entire aquifer (down to 28 m) to recover completely, although the top 6 m of the aquifer may become fresh in about 5 years. 相似文献
3.
This paper presents tsunami intensity mapping and damage patterns along the surveyed coast of Tamilnadu (India) of the deadly
Indian Ocean tsunami of December 26, 2004. The tsunami caused severe damage and claimed many victims in the coastal areas
of eleven countries bordering the Indian Ocean. A twelve-stage tsunami intensity scale proposed by Papadopoulos and Imamura
(2001) was followed to assign the intensity at the visited localities. Along the coast of the Indian mainland, tsunami damage
sustained exclusively. Most severe damage was observed in Nagapattinam Beach, Nabiyarnagar, Vellaipalyam, and the Nagapattinam
Port of Nagapattinum District on the east coast and Keelamanakudy village of Kanyakumari District on the western coast of
Tamilnadu. The maximum assigned tsunami intensity was X+ at these localities. Minimum intensity V+ was received along the coast of Thanjavur, Puddukkotai and Ramnathpuram Districts in Palk Strait. The general observation
reported by many people was that the first arrival was a tsunami crest. The largest tsunami waves were first arrivals on the
eastern coast and the second arrivals on the western coast. Along the coast, people were unaware of the tsunami, and no anomalous
behavior of ocean animals was reported. Good correlation was observed between the severity of damage and the presence of shadow
zone of Sri Lanka, reflected waves from Sri Lanka and the Maldives Islands, variation in the width of the continental shelf,
elevation of the coast and the presence of breakwaters. The presence of medu (naturally elevated landmass very close to the
sea shore and elongated parallel to the coast) reduced the impact of the tsunami on the built environment. 相似文献
4.
Alexander B. Rabinovich Richard E. Thomson Fred E. Stephenson 《Surveys in Geophysics》2006,27(6):647-677
The M
w=9.3 megathrust earthquake of December 26, 2004 off the coast of Sumatra in the Indian Ocean generated a catastrophic tsunami that caused widespread damage in coastal areas and left more than 226,000 people dead or missing. The Sumatra tsunami was accurately recorded by a large number of tide gauges throughout the world's oceans. This paper examines the amplitudes, frequencies and wave train structure of tsunami waves recorded by tide gauges located more than 20,000 km from the source area along the Pacific and Atlantic coasts of North America. 相似文献
5.
The Mw = 9.3 megathrust earthquake of December 26, 2004 off the northwest coast of Sumatra in the Indian Ocean generated a catastrophic
tsunami that was recorded by a large number of tide gauges throughout the World Ocean. Part 1 of our study of this event examines
tide gauge measurements from the Indian Ocean region, at sites located from a few hundred to several thousand kilometers from
the source area. Statistical characteristics of the tsunami waves, including wave height, duration, and arrival time, are
determined, along with spectral properties of the tsunami records. 相似文献
6.
Toshitaka Baba Richard Mleczko David Burbidge Phil R. Cummins Hong Kie Thio 《Pure and Applied Geophysics》2008,165(11-12):2003-2018
The effect of offshore coral reefs on the impact from a tsunami remains controversial. For example, field surveys after the 2004 Indian Ocean tsunami indicate that the energy of the tsunami was reduced by natural coral reef barriers in Sri Lanka, but there was no indication that coral reefs off Banda Aceh, Indonesia had any effect on the tsunami. In this paper, we investigate whether the Great Barrier Reef (GBR) offshore Queensland, Australia, may have weakened the tsunami impact from the 2007 Solomon Islands earthquake. The fault slip distribution of the 2007 Solomon Islands earthquake was firstly obtained by teleseismic inversion. The tsunami was then propagated to shallow water just offshore the coast by solving the linear shallow water equations using a staggered grid finite-difference method. We used a relatively high resolution (approximately 250 m) bathymetric grid for the region just off the coast containing the reef. The tsunami waveforms recorded at tide gauge stations along the Australian coast were then compared to the results from the tsunami simulation when using both the realistic 250 m resolution bathymetry and with two grids having fictitious bathymetry: One in which the the GBR has been replaced by a smooth interpolation from depths outside the GBR to the coast (the “No GBR” grid), and one in which the GBR has been replaced by a flat plane at a depth equal to the mean water depth of the GBR (the “Average GBR” grid). From the comparison between the synthetic waveforms both with and without the Great Barrier Reef, we found that the Great Barrier Reef significantly weakened the tsunami impact. According to our model, the coral reefs delayed the tsunami arrival time by 5–10 minutes, decreased the amplitude of the first tsunami pulse to half or less, and lengthened the period of the tsunami. 相似文献
7.
8.
Zygmunt Kowalik William Knight Tom Logan Paul Whitmore 《Pure and Applied Geophysics》2007,164(2-3):379-393
A numerical model for the global tsunamis computation constructed by Kowalik et al. (2005), is applied to the tsunami of 26 December, 2004 in the World Ocean from 80°S to 69°N with spatial resolution of one
minute. Because the computational domain includes close to 200 million grid points, a parallel version of the code was developed
and run on a Cray X1 supercomputer. An energy flux function is used to investigate energy transfer from the tsunami source
to the Atlantic and Pacific Oceans. Although the first energy input into the Pacific Ocean was the primary (direct) wave,
reflections from the Sri Lankan and eastern shores of Maldives were a larger source. The tsunami traveled from Indonesia,
around New Zealand, and into the Pacific Ocean by various routes. The direct path through the deep ocean to North America
carried miniscule energy, while the stronger signal traveled a considerably longer distance via South Pacific ridges as these
bathymetric features amplified the energy flux vectors. Travel times for these amplified energy fluxes are much longer than
the arrival of the first wave. These large fluxes are organized in the wave-like form when propagating between Australia and
Antarctica. The sources for the larger fluxes are multiple reflections from the Seychelles, Maldives and a slower direct signal
from the Bay of Bengal. The energy flux into the Atlantic Ocean shows a different pattern since the energy is pumped into
this domain through the directional properties of the source function. The energy flow into the Pacific Ocean is approximately
75% of the total flow to the Atlantic Ocean. In many locations along the Pacific and Atlantic coasts, the first arriving signal,
or forerunner, has lower amplitude than the main signal which often is much delayed. Understanding this temporal distribution
is important for an application to tsunami warning and prediction. 相似文献
9.
Yoshinobu Tsuji Fumihiko Imamura Hideo Matsutomi Costas E. Synolakis Puspito T. Nanang Jumadi Satoshi Harada Se Sub Han Ken'ichi Arai Benjamin Cook 《Pure and Applied Geophysics》1995,144(3-4):839-854
A field survey of the June 3, 1994 East Java earthquake tsunami was conducted within three weeks, and the distributions of the seismic intensities, tsunami heights, and human and house damages were surveyed. The seismic intensities on the south coasts of Java and Bali Islands were small for an earthquake with magnitudeM 7.6. The earthquake caused no land damage. About 40 minutes after the main shock, a huge tsunami attacked the coasts, several villages in East Java Province were damaged severely, and 223 persons perished. At Pancer Village about 70 percent of the houses were swept away and 121 persons were killed by the tsunami. The relationship between tsunami heights and distances from the source shows that the Hatori's tsunami magnitude wasm=3, which seems to be larger for the earthquake magnitude. But we should not consider this an extraordinary event because it was pointed out byHatori (1994) that the magnitudes of tsunamis in the Indonesia-Philippine region generally exceed 1–2 grade larger than those of other regions. 相似文献
10.
Jose C. Borrero Brian McAdoo Bruce Jaffe Lori Dengler Guy Gelfenbaum Bretwood Higman Rahman Hidayat Andrew Moore Widjo Kongko Lukijanto Robert Peters Gegar Prasetya Vasily Titov Eko Yulianto 《Pure and Applied Geophysics》2011,168(6-7):1075-1088
On the evening of March 28, 2005 at 11:09?p.m. local time (16:09 UTC), a large earthquake occurred offshore of West Sumatra, Indonesia. With a moment magnitude (M w) of 8.6, the event caused substantial shaking damage and land level changes between Simeulue Island in the north and the Batu Islands in the south. The earthquake also generated a tsunami, which was observed throughout the source region as well as on distant tide gauges. While the tsunami was not as extreme as the tsunami of December 26th, 2004, it did cause significant flooding and damage at some locations. The spatial and temporal proximity of the two events led to a unique set of observational data from the earthquake and tsunami as well as insights relevant to tsunami hazard planning and education efforts. 相似文献
11.
John McCloskey Andrea Antonioli Alessio Piatanesi Kerry Sieh Sandy Steacy Suleyman Nalbant Massimo Cocco Carlo Giunchi JianDong Huang Paul Dunlop 《Earth and Planetary Science Letters》2008,265(1-2):61-81
Several independent indicators imply a high probability of a great (M > 8) earthquake rupture of the subduction megathrust under the Mentawai Islands of West Sumatra. The human consequences of such an event depend crucially on its tsunamigenic potential, which in turn depends on unpredictable details of slip distribution on the megathrust and how resulting seafloor movements and the propagating tsunami waves interact with bathymetry. Here we address the forward problem by modelling about 1000 possible complex earthquake ruptures and calculating the seafloor displacements and tsunami wave height distributions that would result from the most likely 100 or so, as judged by reference to paleogeodetic data. Additionally we carry out a systematic study of the importance of the location of maximum slip with respect to the morphology of the fore-arc complex. Our results indicate a generally smaller regional tsunami hazard than was realised in Aceh during the December 2004 event, though more than 20% of simulations result in tsunami wave heights of more than 5 m for the southern Sumatran cities of Padang and Bengkulu. The extreme events in these simulations produce results which are consistent with recent deterministic studies. The study confirms the sensitivity of predicted wave heights to the distribution of slip even for events with similar moment and reproduces Plafker's rule of thumb. Additionally we show that the maximum wave height observed at a single location scales with the magnitude though data for all magnitudes exhibit extreme variability. Finally, we show that for any coastal location in the near field of the earthquake, despite the complexity of the earthquake rupture simulations and the large range of magnitudes modelled, the timing of inundation is constant to first order and the maximum height of the modelled waves is directly proportional to the vertical coseismic displacement experienced at that point. These results may assist in developing tsunami preparedness strategies around the Indian Ocean and in particular along the coasts of western Sumatra. 相似文献
12.
Sumatra tsunami: lessons from modeling 总被引：1，自引：0，他引：1
The need for the combination of seismic data with real-time wave height information for an effective prediction of tsunami impact is emphasized in the paper. A preliminary, but comprehensive study of arrival times, wave heights and run-up values at a number of locations and tide gage stations throughout the Indian Ocean seaboard is presented. Open ocean wave height data from satellite observations are analyzed and used in the reconstruction of a tsunami source mechanism for the December 26, 2004 event. The reconstructed source is then used to numerically estimate tsunami impact along the Indian Ocean seaboard, including wave height, and arrival times at 12 tide gage stations, and inundation at 3 locations on the coast of India. The December 2004, as well as the March 28, 2005 tsunamis are investigated and their differences in terms of tsunami generation are analyzed and presented as a clear example of the need for both, seismic and real-time tsunami data for a reliable tsunami warning system in the Indian Ocean. 相似文献
13.
J. J. Wijetunge 《Pure and Applied Geophysics》2009,166(4):593-622
This paper employs a numerical model of tsunami propagation together with documented observations and field measurements of
the evidence left behind by the tsunami in December 2004, to identify and interpret the factors that have contributed to the
significant spatial variability of the level of tsunami impact along the coastal belt of the eastern province of Sri Lanka.
The model results considered in the present analysis include the distribution of the amplitude of the tsunami and the pattern
of wave propagation over the continental shelf off the east coast, while the field data examined comprise the maximum water
levels measured at or near the shoreline, the horizontal inundation distances and the number of housing and other buildings
damaged. The computed maximum amplitude of the tsunami at water points nearest the shoreline along the east coast shows considerable
variation ranging from 2.2 m to 11.4 m with a mean value of 5.7 m; moreover, the computed amplitudes agree well with the available
field measurements. We also show that the shelf bathymetry off the east coast, particularly the submarine canyons at several
locations, significantly influences the near-shore transformation of tsunami waves, and consequently, the spatial variation
of the maximum water levels along the coastline. The measured values of inundation also show significant variation along the
east coast and range from 70 m to 4560 m with a median value of 700 m. Our analyses of field data also show the dominant influence
of the coastal topography and geomorphology on the extent of tsunami inundation. Furthermore, the measured inundation distances
indicate no apparent correlation with the computed tsunami heights at the respective locations. We also show that both the
computed tsunami heights and the measured inundation distances for the east coast closely follow the log-normal statistical
distribution. 相似文献
14.
Franck Lavigne Raphaël Paris Delphine Grancher Patrick Wassmer Daniel Brunstein Franck Vautier Frédéric Leone François Flohic Benjamin De Coster Taufik Gunawan Christopher Gomez Anggri Setiawan Rino Cahyadi Fachrizal 《Pure and Applied Geophysics》2009,166(1-2):259-281
This paper presents the results from an extensive field data collection effort following the December 26, 2004 earthquake and tsunami in Banda Aceh, Sumatra. The data were collected under the auspices of TSUNARISQUE, a joint French-Indonesian program dedicated to tsunami research and hazard mitigation, which has been active since before the 2004 event. In total, data from three months of field investigations are presented, which detail important aspects of the tsunami inundation dynamics in Banda Aceh. These include measurements of runup, tsunami wave heights, flow depths, flow directions, event chronology and building damage patterns. The result is a series of detailed inundation maps of the northern and western coasts of Sumatra including Banda Aceh and Lhok Nga. Among the more important findings, we obtained consistent accounts that approximately ten separate waves affected the region after the earthquake; this indicates a high-frequency component of the tsunami wave energy in the extreme near-field. The largest tsunami wave heights were on the order of 35 m with a maximum runup height of 51 m. This value is the highest runup value measured in human history for a seismically generated tsunami. In addition, our field investigations show a significant discontinuity in the tsunami wave heights and flow depths along a line approximately 3 km inland, which the authors interpret to be the location of the collapse of the main tsunami bore caused by sudden energy dissipation. The propagating bore looked like a breaking wave from the landward side although it has distinct characteristics. Patterns of building damage are related to the location of the propagating bore with overall less damage to buildings beyond the line where the bore collapsed. This data set was built to be of use to the tsunami community for the purposes of calibrating and improving existing tsunami inundation models, especially in the analysis of extreme near-field events. 相似文献
15.
Evaluating Tsunami Hazard in the Northwestern Indian Ocean 总被引：1，自引：0，他引：1
Mohammad Heidarzadeh Moharram D. Pirooz Nasser H. Zaker Costas E. Synolakis 《Pure and Applied Geophysics》2008,165(11-12):2045-2058
We evaluate here the tsunami hazard in the northwestern Indian Ocean. The maximum regional earthquake calculated from seismic hazard analysis, was used as the characteristic earthquake for our tsunami hazard assessment. This earthquake, with a moment magnitude of M w 8.3 and a return period of about 1000 years, was moved along the Makran subduction zone (MSZ) and its possible tsunami wave height along various coasts was calculated via numerical simulation. Both seismic hazard analysis and numerical modeling of the tsunami were validated using historical observations of the Makran earthquake and tsunami of the 1945. Results showed that the possible tsunami may reach a maximum height of 9.6 m in the region. The distribution of tsunami wave height along various coasts is presented. We recommend the development of a tsunami warning system in the region, and emphasize the value of education as a measure to mitigate the death toll of a possible tsunami in this region. 相似文献
16.
2004年12月26日苏门答腊岛安达曼海附近海域发生的9．0级地震和2005年3月28日苏门答腊岛明打威群岛北附近海域的8．7级地震,在构造环境、震级、震源深度、地震类型都相似的情况下,为何前者引发海啸,后者不引发的海啸？对此进行了对比分析,认为9．0级地震发生时,在其震源体附近的两板块相交的海沟两侧陡坡蕴育着滑坡体或和崩塌体（或者两者都有）,9．0级地震发生时,强烈的地震波,促使滑坡体的滑动或崩塌体的崩塌,推压和扰动海水,引发诲啸。而8．7级地震发生时、在其震源体附近的两板块相交的海沟两侧陡坡无滑坡体或和崩塌体,或先存滑坡体或崩塌体在9．0级地震发生时已滑坡或崩塌殆尽,当8.7地震发生时,无滑坡体滑动或崩塌体崩塌,不可能对海水有较大的扰动,故不可能引发海啸。 相似文献
17.
18.
John Davis Jakeman Ole M. Nielsen Kristy Van Putten Richard Mleczko David Burbidge Nick Horspool 《Ocean Dynamics》2010,60(5):1115-1138
This paper presents a framework and data for spatially distributed assessment of tsunami inundation models. Our associated
validation test is based upon the 2004 Indian Ocean tsunami, which affords a uniquely large amount of observational data for
events of this kind. Specifically, we use eyewitness accounts to assess onshore flow depths and speeds as well as a detailed
inundation survey of Patong City, Thailand to compare modelled and observed inundation. Model predictions matched well the
detailed inundation survey as well as altimetry data from the JASON satellite, eyewitness accounts of wave front arrival times
and onshore flow speeds. Important buildings and other structures were incorporated into the underlying elevation model and
are shown to have a large influence on inundation extent. 相似文献
19.
Twin Tsunamis Triggered by the 12 January 2010 Haiti Earthquake 总被引：2，自引：0，他引：2
Hermann M. Fritz Jean Vilmond Hillaire Emanuel Molière Yong Wei Fahad Mohammed 《Pure and Applied Geophysics》2013,170(9-10):1463-1474
On 12 January 2010, a magnitude M w 7.0 earthquake occurred 25 km west–southwest of Haiti’s capital Port-au-Prince causing an estimated 316,000 fatalities, thereby exceeding any previous loss of life from a similar size earthquake. In addition, tsunami waves triggered by the earthquake caused at least three fatalities at Petit Paradis due to a complete lack of tsunami awareness. The International Tsunami Survey Team (ITST) was deployed within weeks of the event and covered the greater Bay of Port-au-Prince and more than 100 km of Hispaniola’s southern coastline. The collected survey data include more than 21 tsunami heights along with observations of coastal land level change. Maximum tsunami heights of 3 m have been measured for two independently triggered tsunamis. 相似文献