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1.
The National Geophysical Data Center and co-located World Data Center for Geophysics and Marine Geology provide integrated access to historical tsunami event, deposit, and proxy data. Historical events are important for understanding the frequency and intensity of relatively recent tsunamis. Deposit data collected during post-tsunami field surveys provide information on tsunami erosion, sedimentation, flow depths, inundation, and run-up. Deposit data from prehistoric tsunami events extend the record to pre-recorded times, constrain tsunami recurrence intervals, and estimate the minimum magnitude of tsunami inundation. Proxies indicate that an event capable of producing a tsunami occurred, but are not direct evidence of a tsunami. All of these data are used to develop tsunami hazard assessments, provide guidance to warning centers, validate models, inform community preparedness efforts, and educate the public about tsunami risks. 相似文献
2.
By combining landslide dynamics research and tsunami research, we present an integrated series of numerical models quantitatively simulating the complete evolution of a landslide-induced tsunami. The integrated model simulating the landslide initiation and motion uses measured landslide dynamic parameters from a high-stress undrained dynamic-loading ring shear apparatus. It provides the numerical data of a landslide mass entering and moving under water to the tsunami simulation model as the trigger of tsunami. The series of landslide and tsunami simulation models were applied to the 1792 Unzen-Mayuyama megaslide and the ensuing tsunami disaster, which is the largest landslide disaster, the largest volcanic disaster, and the largest landslide-induced tsunami disaster to have occurred in Japan. Both the 1792 megaslide and the tsunami portions of the disaster are well documented, making this an excellent test of the reliability and precision of the new simulation model. The simulated tsunami heights at the coasts well match the historical tsunami heights recorded by “Tsunami-Dome-Ishi” (a stone showing the tsunami reaching point) and memorial stone pillars. 相似文献
3.
Following the catastrophic “Great Sumatra–Andaman” earthquake- tsunami in the Indian Ocean on the 26th December 2004, questions
have been asked about the frequency and magnitude of tsunami within the region. We present a summary of the previously published
lists of Indian Ocean Tsunami (IOT) and the results of a preliminary search of archival materials held at the India Records
Office, at the British Library in London. We demonstrate that in some cases, normal tidal movements and floods associated
with tropical cyclones have been erroneously listed as tsunami. We summarise archival material for tsunami that occurred in
1945, 1941, 1881, 1819, 1762 and a little known tsunami in 1843. We present the results of modelling of the 2004, 1861 and
1833 tsunami generated by earthquakes off Sumatra and the 1945 Makran earthquake and tsunami, and examine how these results
help to explain some of the historical observations. The highly directional component to tsunami propagation illustrated by
the numerical models may explain why we are unable to locate archival records of the 1861 and 1833 tsunami at important locations
like Rangoon, Kolkata (formally Calcutta) and Chennai (formally Madras), despite reports that these events created large tsunami
that inundated western Sumatra. The numerical models identify other areas (particularly the central and southern Indian Ocean
islands) where the 1833 tsunami may have had a large enough effect to produce a historic record. We recommend further archival
research, coastal geological investigations of tsunami impacts and detailed modelling of tsunami propagation to better understand
the record and effects of tsunami in the Indian Ocean and to estimate their likelihood of occurring in the future. 相似文献
4.
地震与海啸关系探讨 总被引：4，自引：1，他引：4
何永金 《水文地质工程地质》2005,32(6):82-84
本文探讨了海啸、地震和它们的成因。作者认为,破坏性地震常伴生着破坏性海啸,但地震不会直接引发海啸。构造地震和地壳变动型海啸之间不是因果关系,而是伴生或共生关系。此外,本文还探讨了破坏性海啸的形成条件和控制地震震级的主要因素。 相似文献
5.
This paper presents a simple model for tsunami sedimentation that can be applied to calculate tsunami flow speed from the thickness and grain size of a tsunami deposit (the inverse problem). For sandy tsunami deposits where grain size and thickness vary gradually in the direction of transport, tsunami sediment transport is modeled as a steady, spatially uniform process. The amount of sediment in suspension is assumed to be in equilibrium with the steady portion of the long period, slowing varying uprush portion of the tsunami. Spatial flow deceleration is assumed to be small and not to contribute significantly to the tsunami deposit. Tsunami deposits are formed from sediment settling from the water column when flow speeds on land go to zero everywhere at the time of maximum tsunami inundation. There is little erosion of the deposit by return flow because it is a slow flow and is concentrated in topographic lows. Variations in grain size of the deposit are found to have more effect on calculated tsunami flow speed than deposit thickness. The model is tested using field data collected at Arop, Papua New Guinea soon after the 1998 tsunami. Speed estimates of 14 m/s at 200 m inland from the shoreline compare favorably with those from a 1-D inundation model and from application of Bernoulli's principle to water levels on buildings left standing after the tsunami. As evidence that the model is applicable to some sandy tsunami deposits, the model reproduces the observed normal grading and vertical variation in sorting and skewness of a deposit formed by the 1998 tsunami. 相似文献
6.
Xu Zhiguo Sun Lining Rahman Mohd Nashriq Abd Liang Shanshan Shi Jianyu Li Hongwei 《Natural Hazards》2022,111(3):2703-2719
A major left-lateral strike-slip Mw7.7 earthquake occurred in the vicinity of the Caribbean Sea on January 28, 2020. As a result, a small-scale tsunami was generated. The properties of the seismogenic source were described using observational data gathered for the earthquake and tsunami, as well as information on the regional tectonic setting. The tsunami was simulated with the COMCOT model and Okada’s dislocation model from finite fault solutions for MW7.7 Caribbean Sea earthquakes published by the United States Geological Survey. The simulation results were compared to tide gauge records to validate whether the seafloor’s vertical displacement generated by the strike-slip fault caused a small-scale tsunami. We conducted a spectral analysis of the tsunami to better understand the characteristics of tsunami records. The tsunami simulation results showed that the co-seismic vertical displacement caused by a strike-slip MW7.7 earthquake could have contributed to the small-scale tsunami, but the anomalously large high-frequency tsunami waves recorded by the George Town tide gauge 11 min after the earthquake were unrelated to the earthquake-generated tsunami. According to the spectrum analysis, the predominant period of noticeable high-frequency tsunami waves recorded by the George Town tide gauge occurred only two minutes after the earthquake. This indicates that the source of the small-scale tsunami was close to the George Town station and the possible tsunami source was 150 km away from George Town station. These facts suggest that a submarine landslide was caused by the strike-slip earthquake. The comprehensive analysis showed that the small-scale tsunami was not caused solely by co-seismic seafloor deformation from the strike-slip event but that an earthquake-triggered submarine landslide was the primary cause. Therefore, the combined impact of two sources led to the small-scale tsunami.
相似文献7.
A coupled hydrostatic and morph-dynamic model COMCOT-SED was used to investigate the morphological change in Lhok Nga bay during the 2004 Indian Ocean tsunami, and the coupled model predicted the thickness of tsunami deposits in agreement with the measured ones. The relationship between the characteristics of tsunami deposit and flow hydrodynamics was discussed in details. Phenomena such as landward thinning in deposit thickness, landward fining in grain size, and fining upwards in grain size are commonly used to identify tsunami deposits and were examined in this case study. We also discussed the effects of sediment supplies and the constraints that can be put on the earthquake parameters using the information derived from tsunami deposits. This study shows that the model presented in this paper is capable of simulating extreme tsunami events (tsunami wave height ~30?m) in a large domain and that forward models of tsunami sediment transport can be a promising tool to help tsunami geologists understand tsunami deposits. 相似文献
8.
An accurate assessment of tsunami risk of a region requires a credible record of past tsunami events in the region. Existing
surveys on historical tsunamis of South China have not presented a consistent list of events. The current report makes reference
to original historical literature and evaluates the validity of suspected tsunami events in published surveys. A set of refined
historical data for further investigation of the tsunami hazard in the region was produced. Only two events have been identified
as credible reports of tsunami in the current study. Some events previously considered as tsunami, including a few with great
reported casualties, are found to be unsubstantiable. 相似文献
9.
Tsunami in the last 15 years: a bibliometric analysis with a detailed overview and future directions
In the last fifteen years, tsunami science has progressed at a rapid pace. Three major tsunamis: The Indian Ocean in 2004, the 2011 Tohoku tsunami, and the 2018 Palu tsunami were significant landmarks in the history of tsunami science. All the three tsunamis, as mentioned, suffered from either no warning or poor reception of the alerts issued. Various lessons learned, consequent numerical models proposed, post-2004 tsunami damage findings manifested into solutions. However, the misperceived solutions led to a disastrous impact of the 2011 Tohoku event. In the following years, numerous improvements in warning systems and community preparedness frameworks were proposed and implemented. The contributions and new findings have added multi-fold advancements to tsunami science progress. Later, the 2018 Palu tsunami happened and again led to a massive loss of life and property. The warning systems and community seemed un-prepared for this non-seismic tsunami. A significant change is to take place in tsunami science practices and solutions. The 2018 tsunami is one of the most discussed and researched events concerning the palaeotsunami records, damage assessment, and source findings. In the new era, using machine learning and deep learning prevails in all the fields related to tsunami science. This article presents a complete 15-year bibliometric analysis of tsunami research from Scopus and Web of Science (WoS). The review of majorly cited documents in the form of a progressing storyline has highlighted the need for multidisciplinary research to design and propose practical solutions.
相似文献10.
Here we perform an inventory of tsunamis recorded by tide gauges in the Pacific coast of Costa Rica. This paper also reveals nine tsunami records that had not been published before, at Puntarenas tide gauge corresponding to the 1979 Colombia tsunami and at Quepos tide gauge corresponding to the 1985 Mexico twin tsunamis, the 2010, 2014 and 2015 Chile tsunamis, the 2006 Tonga tsunami, the 2011 Japan tsunami and the 2013 Solomon Islands tsunami. The original record of 1990 Cóbano tsunami at Quepos was digitized again at a higher resolution and re-processed. The arrival of 1979, 1985, 2006 and 2014 tsunamis to Costa Rica is not listed on tsunami catalogs. The maximum tsunami height obtained here after processing 1990, 2011 and 2013 records was higher than reported on catalogs. The opposite happened for the 2010 tsunami. Quepos gauge record for January 2007 was analyzed as it seemed to have registered the Kuril Islands tsunami, but the results were not conclusive due to the low sample rate and the small tsunami amplitude if any. All those eleven tsunamis were modeled and the results compared with the records. A good agreement was obtained for the Quepos gauge, although the modeled 2011 and 2013 tsunamis had a difference of 8 min on the arrival time. An acceptable agreement was obtained for the Puntarenas gauge for 1979 tsunami, considering at least the first 4 h of the marigram is lost. 相似文献
11.
Run-up and Inundation Pattern Developed During the Indian Ocean Tsunami of December 26, 2004 Along the Coast of Tamilnadu (India) 总被引：1，自引：0，他引：1
The tsunami run-up, inundation and damage pattern observed along the coast of Tamilnadu (India) during the deadliest Indian Ocean tsunami of December 26, 2004 is documented in this paper. The tsunami caused severe damage and claimed many victims in the coastal areas of eleven countries, bordering the Indian Ocean. Along the coast of Indian mainland, the damage was caused by the tsunami only. Largest tsunami run-up and inundation was observed along the coast of Nagapattinam district and was about 10–12 m and 3.0 km, respectively. The measured inundation data were strongly scattered in direct relationship to the morphology of the seashore and the tsunami run-up. Lowest tsunami run-up and inundation was measured along the coast of Thanjavur, Puddukkotai and Ramnathpuram districts of Tamilnadu in the Palk Strait. The presence of shadow of Sri Lanka, the interferences of direct/receded waves with the reflected waves from Sri Lanka and Maldive Islands and variation in the width of continental shelf were the main cause of large variation in tsunami run-up along the coast of Tamilnadu. 相似文献
12.
Tsunamis versus storm deposits from Thailand 总被引：3，自引：0，他引：3
Along the Andaman (west) coast of Thailand, the 2004 tsunami depositional features associated with the 2004 tsunami were used to describe the characteristics of tsunamis in a place far away from the effect of both recent and ancient storms. The current challenge is that a lack of precise sedimentological characteristics have been described that will differentiate tsunami deposits from storm deposits. Here, in sedimentological senses, we reviewed the imprints of the sedimentological characteristics of the 2004 tsunami and older deposits and then compared them with storm deposits, as analyzed from the deposits found along the eastern (Gulf of Thailand; GOT) coast of Thailand. We discuss the hydraulic conditions of the 2004 tsunami and its predecessors, on the Andaman coast, and compare them to storm flows found on the coast of the GOT. Similar to an extensive tsunami inflow deposit, a storm flow overwash has very similar sedimentary structures. Well-preserved sedimentary structures recognized in sand sheets from both tsunami and storms include single and multiple normal gradings, reverse grading, parallel, incline and foreset lamina, rip-up clasts, and mud drapes. All these sedimentary structures verify the similarity of tsunami and storm inflow behavior as both types of high-energy flow start to scour the beach zone. Antidunes are likely to be the only unique internal sedimentary structures observed in the 2004 tsunami deposit. Rip-up clasts are rare within storm deposits compared to tsunami deposits. We found that the deposition during the outflow from both tsunami and storms was rarely preserved, suggesting that it does not persist for very long in the geological record. 相似文献
13.
N. Nirupama 《Natural Hazards》2009,48(1):11-16
For the assessment of tsunami risk and vulnerability, one has to make use of past tsunami observations. The most comprehensive
tsunami databases for the world have been prepared by the National Geophysical Data Center of USA which are listed on their
website for all the four oceans as well as the following marginal seas: Caribbean Sea, Mediterranean Sea, Black Sea, Red Sea
and Gulf of Mexico. The dataset goes back as far as the first century AD and lists the events on a confidence rating scale
of 0–4; 0 being an erroneous entry and 4 being a definite tsunami. Based on these various datasets for different geographical
areas, a comprehensive global dataset was prepared in this study, which included only tsunami events with confidence rating
of 3 and 4, meaning either probable or definite. In this composite and abridged global tsunami database there is no distinction
either according to geography or tsunami strength as implied by its impact on the coast. A simple and straightforward statistical
analysis suggests an almost complete randomness and no patterns that can be used for future tsunami predictions with a few
minor exceptions. 相似文献
14.
A case study was conducted for the Thailand Khao Lak coast using a forward numerical model to understand uncertainties associated with interpreting tsunami deposits and relating them to their tsunami sources. We examined possible effects of the characteristics of tsunami source, multiple waves, sediment supply and local land usages. Numerical results showed that tsunami-deposit extent and thickness could be indicative of the slip value in the source earthquake near the surveyed coastal locations, provided that the sediment supply is unlimited and all the deposits are well preserved. Deposit thickness was found to be largely controlled by the local topography and could be easily modified by backwash flows or subsequent tsunami flows. Between deposit extent and deposit thickness, using deposit extent to interpret the characteristics of a tsunami source is preferable. The changing of land usages between two tsunami events could be another important factor that can significantly alter deposit thickness. There is a need to develop inversion models based on tsunami heights and/or run-up data for studying paleotsunamis. 相似文献
15.
R. Jelínek E. Krausmann M. González J. A. Álvarez-Gómez J. Birkmann T. Welle 《Natural Hazards》2012,60(2):273-293
Tsunamis can represent a significant risk to the population and cause huge economic damage in many costal regions. In order
to be able to identify risk hot spots and implement targeted risk reduction measures, decision makers need to have a clear
picture of the risk situation in their countries or regions. This work reviews existing approaches for tsunami risk assessment
and recommends a five-step process for assessing tsunami risk. As a case study, a qualitative risk assessment for a worst-case
tsunami scenario was carried out to understand the tsunami risk to the population in Cádiz. Moreover, a sensitivity analysis
of the tsunami hazard input parameters was performed as a strong influence of the variability of the input parameters on the
resultant tsunami hazard and risk zonation maps was observed. The study shows that regardless of the assumptions made a non-negligible
tsunami risk to Cádiz exists. 相似文献
16.
Shunichi Koshimura Toshitaka Katada Harold O. Mofjeld Yoshiaki Kawata 《Natural Hazards》2006,39(2):265-274
This study develops a method for estimating the number of casualties that may occur while people evacuate from an inundation
zone when a tsunami has inundated an area. The method is based on a simple model of hydrodynamic forces as they affect the
human body. The method uses a Tsunami casualty index (TCI) computed at each grid point of a numerical tsunami model to determine
locations and times within the tsunami inundation zone where evacuation during the tsunami inundation is not possible and
therefore where casualties are likely to occur. The locations and times can be combined with information about population
density to compute the potential number of casualties. This information is useful in developing tsunami evacuation routes
that avoid such locations. To illustrate the method, it is applied to the Seattle waterfront in Washington State, USA, that
is under the threat of possible tsunami disasters due to Seattle Fault earthquakes. Preliminary results suggest that the tsunami
casualties may occur within the Seattle waterfront for 15 min, during the time interval from 3 to 18 min after a large Seattle
Fault tsunami is generated when the background tide level is mean high water. 相似文献
17.
Large Scale Rockfall Reach Susceptibility Maps in La Cabrera Sierra (Madrid) performed with GIS and Dynamic Analysis at 1:5,000 总被引：1，自引：0，他引：1
Ayala-Carcedo Francisco J. Cubillo-Nielsen Silvia Alvarez Ana Domínguez María J. Laín Luis Laín Ricardo Ortiz Guillermo 《Natural Hazards》2003,29(3):325-340
For the testing of the effect on the tsunami prevention facilities, a simplified methodfor tsunami risk assessment was suggested without wave run-up analysis. This methodis proposed using calculated offshore tsunami waveform and field reconnaissance suchas the seawall height, time necessary for residents' evacuation and tsunami warninginsurance. Then, two normalized values are evaluated; one is the ratio of calculatedmaximum tsunami height to seawall height, the other is the ratio of time betweentsunami over-topping and evacuation completion to total time required for evacuation.These two values are used to qualitatively estimate the safety of residents and the effectof tsunami prevention facilities, eliminating the necessity to compute complicatedtsunami run-up onshore. 相似文献
18.
The Makassar Strait region has had the highest frequency of historical tsunamievents for Indonesia. The strait has a seismic activity due to the convergenceof four tectonic plates that produces a complex mixture of structures. The maintsunamigenic features in the Makassar Strait are the Palu-Koro and Pasternostertransform fault zones, which form the boundaries of the Makassar trough.Analysis of the seismicity, tectonics and historic tsunami events indicatesthat the two fault zones have different tsunami generating characteristics.The Palu-Koro fault zone involves shallow thrust earthquakes that generatetsunami that have magnitudes that are consistent with the earthquakemagnitudes. The Pasternoster fault zone involves shallower strike-slipearthquakes that produce tsunami magnitudes larger than would normallybe expected for the earthquake magnitude. The most likely cause for theincreased tsunami energy is considered to be submarine landslidesassociated with the earthquakes. Earthquakes from both fault zonesappear to cause subsidence of the west coast of Sulawesi Island.The available data were used to construct a tsunami hazard map whichidentifies the highest risk along the west coast of Sulawesi Island.The opposite side of the Makassar Strait has a lower risk because it isfurther from the historic tsunami source regions along the Sulawesicoast, and because the continental shelf dissipates tsunami wave energy.The greatest tsunami risk for the Makassar Strait is attributed tolocally generated tsunami due to the very short travel times. 相似文献
19.
The post-depositional changes of the onshore 2004 tsunami deposits on the Andaman Sea coast of Thailand 总被引：2，自引：1，他引：1
Witold Szczuciński 《Natural Hazards》2012,60(1):115-133
The Indian Ocean tsunami flooded the coastal zone of the Andaman Sea and left tsunami deposits with a thickness of a few millimetres
to tens of centimetres over a roughly one-kilometre-wide tsunami inundation zone. The preservation potential and the post-depositional
changes of the onshore tsunami deposits in the coastal plain setting, under conditions of a tropical climate with high seasonal
rainfall, were assessed by reinvestigating trenches located along 13 shore-perpendicular transects; the trenches were documented
shortly after the tsunami and after 1, 2, 3 and 4 years. The tsunami deposits were found preserved after 4 years at only half
of the studied sites. In about 30% of the sites, the tsunami deposits were not preserved due to human activity; in a further
20% of the sites, the thin tsunami deposits were eroded or not recognised due to new soil formation. The most significant
changes took place during the first rainy season when the relief of the tsunami deposits was levelled; moderate sediment redeposition
took place, and fine surface sediments were washed away, which frequently left a residual layer of coarse sand and gravel.
The fast recovery of new plant cover stabilised the tsunami deposits and protected them against further remobilisation during
the subsequent years. After five rainy seasons, tsunami deposits with a thickness of at least a few centimetres were relatively
well preserved; however, their internal structures were often significantly blurred by roots and animal bioturbation. Moreover,
soil formation within the deposits caused alterations, and in the case of thin layers, it was not possible to recognise them
anymore. Tsunami boulders were only slightly weathered but not moved. Among the various factors influencing the preservation
potential, the thickness of the original tsunami deposits is the most important. A comparison between the first post-tsunami
survey and the preserved record suggests that tsunamis with a run-up smaller than three metres are not likely to be preserved;
for larger tsunamis, only about 50% of their inundation area is likely to be presented by the preserved extent of the tsunami
deposits. Any modelling of paleotsunamis from their deposits must take into account post-depositional changes. 相似文献
20.
Atsushi Noda Hajime Katayama Tsumoru Sagayama Kazuya Suga Yasuhito Uchida Kenji Satake Kohei Abe Yukinobu Okamura 《Sedimentary Geology》2007,200(3-4):314-327
A combined approach of field geology and numerical simulation was conducted for evaluating the tsunami impacts on the shelf sediments. The 2003 Tokachi-oki earthquake, M 8.0, that occurred on 25 September 2003 off southeastern Hokkaido, northern Japan, generated a locally destructive tsunami. Maximum run-up height of the tsunami waves reached 4 m above sea level. In order to estimate the tsunami impacts on shallow marine sediments, we compared pre- and post-tsunami marine sediments in water depths of 38–112 m in terms of grain size, sedimentary structure, and microfossil content. Decreases of fine fractions, especially finer than very fine sand, which led to coarsen the mean grain size, were detected in the inner shelf of the northern part of the study area. Foraminiferal assemblages also changed in the coarsened sediments. On the other hand, the other shelf sediments largely unchanged or slightly fined. We also simulated the tsunami wave velocity and direction, and grain size entrained by the modeled tsunami. The numerical simulation resulted in that the 2003 tsunami could transport very fine sand in water depths shallower than 45–95 m at the northern part of the study area. This is comparable with the actual grain-size changes after the tsunami had passed. However, some storms and tidal currents might also be possible to stir the surface sediments after the pre-tsunami survey, so we could not conclude that the grain-size changes had been caused only by the tsunami. Nevertheless, a combined approach of sampling and modeling was powerful for estimating the tsunami impacts under the sea. 相似文献