The spatio-temporal evolution of the three recent tsunamogenic earthquakes (TsE) off-coast N-Sumatra (Mw9.3), 28/03/2005 (Mw8.5) off-coast Nias, on 17/07/2006 (Mw7.7) off-coast Java. Start time, duration, and propagation of the rupture are retrieved. All parameters can be obtained rapidly after recording of the first-arrival phases in near-real time processing. We exploit semblance analysis, backpropagation and broad-band seismograms within 30°-95° distance. Image enhancement is reached by stacking the semblance of arrays within different directions. For the three events, the rupture extends over about 1150, 150, and 200km, respectively. The events in 2004, 2005, and 2006 had source durations of at least 480s, 120s, and 180s, respectively. We observe unilateral rupture propagation for all events except for the rupture onset and the Nias event, where there is evidence for a bilateral start of the rupture. Whereas average rupture speed of the events in 2004 and 2005 is in the order of the S-wave speed (≈2.5-3km/s), unusually slow rupturing (≈1.5 km/s) is indicated for the July 2006 event. For the July 2006 event we find rupturing of a 200 x 100 km wide area in at least 2 phases with propagation from NW to SE. The event has some characteristics of a circular rupture followed by unilateral faulting with change in slip rate. Fault area and aftershock distribution coincide. Spatial and temporal resolution are frequency dependent. Studies of a Mw6.0 earthquake on 2006/09/21 and one synthetic source show a ≈1° limit in resolution. Retrieved source area, source duration as well as peak values for semblance and beam power generally increase with the size of the earthquake making possible an automatic detection and classification of large and small earthquakes.

Tsunami forecasting methodology developed by the United States National Oceanic and Atmospheric Administration&rsquo / s Center for Tsunami Research is based on the concept of a pre-computed tsunami database which includes tsunami model results from Mw 7.5 earthquakes called tsunami source functions. Tsunami source functions are placed along the subduction zones of the oceans of the world in several rows. Linearity of tsunami propagation in an open ocean allows scaling and/or combination of the pre-computed tsunami source functions. An offshore scenario is obtained through inverting scaled and/or combined tsunami source functions against Deep-ocean Assessment and Reporting of Tsunami (DART) buoy measurements. A graphical user interface called Genetic Algorithm for INversion (GAIN) was developed in MATLAB using general optimization toolbox to perform an inversion. The 15 November 2006 Kuril and 27 February 2010 Chile tsunamis are chosen as case studies. One and/or several DART buoy measurement(s) is/are used to test different error minimization functions with/without earthquake magnitude as constraint. The inversion results are discussed comparing the forecasting model results with the tide gage measurements.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 109-122).

En las últimas décadas, los investigadores han debatido sobre la representación tradicional de la administración española durante el siglo XVII como ineficaz e impotente. Algunos de ellos argumentan que el régimen del último rey Habsburgo fue decadente e ineficaz. En contraposición a esta imagen,los administradores reales de Lima, capital del Virreinato del Perú, mostraron una gran capacidad de organización y manejo de la crisis después de queun intenso terremoto y posterior tsunami azotaron la ciudad y su puerto en1687. En medio del caos y la destrucción causada por este desastre natural,el virrey y los miembros del cabildo de la ciudad fueron capaces de usar loslimitados recursos disponibles y de atender las crecientes demandas materiales y espirituales de la población de Lima.

Lima, capital of Perú, together with El Callao configure a large urban agglomeration of near nine million people that makes one third of the total Peruvian population. It is characterized by huge social and spatial inequalities and serious governance and urban management problems; and it is the siege of the national public establishments, the administrations, banks and big enterprises, which results in the concentration of half of the Peruvian economy. From this perspective, any perturbation of Lima by a disaster might affect not only the city and her inhabitants but also the Peruvian territory as a whole. The purpose of this paper is to argument the need to develop a strictly geographic focus in the scientific research on the management of emergency situations. This demonstration is based on a study made by PACIVUR about the resources available to attend the disasters in Lima and El Callao, under the hypothesis of the occurrence of a great earthquake followed by a tsunami. / Lima, capital del Perú, conforma con el Callao una extensa aglomeración urbana que registra cerca de nueve millones de habitantes o sea un tercio de la población peruana. Caracterizada por grandes desigualdades sociales y espaciales y agudos problemas de gobernabilidad y gestión urbana, la urbe centraliza los poderes públicos nacionales, las administraciones, los bancos y sedesde grandes empresas lo que resulta en la concentración de la mitad de la economía peruana en la aglomeración capital. Desde esta perspectiva, la perturbación de Lima por un desastre afectaríano solamente la ciudad y sus habitantes sino también el territorio peruano en su conjunto. El propósito de este texto es argumentar la necesidad de desarrollar un enfoque específicamente geográfico en las investigaciones científicas sobre el manejo de las situaciones de emergencia. Esta demostración se apoya en un estudio que se hizo sobre los recursos para la atención de desastre en Lima y Callao, en la hipótesis de ocurrencia de un sismo de gran magnitud acompañado de un tsunami.

Le contexte géodynamique du bassin de la Caraïbe, du fait notamment de la présence de zones de subduction et de nombreux édifices volcaniques, est favorable à la génération de tsunamis. La connaissance historique de ce phénomène dans la région, associée à de récents résultats de simulation numérique, confirme ce fort potentiel. Les amplitudes de vagues modélisées à l’approche des côtes avoisinent les 10 m pour certains scénarios. L’aléa tsunami est une menace pour l’ensemble du littoral des territoires du bassin de la Caraïbe. Les enjeux humains, structurels et stratégiques, concentrés massivement sur ce littoral, sont particulièrement exposés à ce phénomène, notamment aux Antilles où le risque associé est très élevé. Aujourd’hui, un système de surveillance et de détection des tsunamis à l’échelle régionale assure la diffusion de messages d’information en cas d’événement. Néanmoins, il n’existe pas de dispositifs pour guider localement les autorités dans leurs prises de décisions pour mettre en sécurité des populations, ou bien ils restent très généralistes, notamment pour les territoires français. Afin d’anticiper ce besoin, nous avons accompagné la planification opérationnelle de la gestion des crises pour les phases d’alerte et d’évacuation temporaire des populations à terre et de la mise en sécurité des navires en mer. Cette démarche, engagée à différentes échelles, repose sur une approche géographique et intégrée de la gestion de crise tsunami, à l’interface des connaissances entre le domaine scientifique et opérationnel. Notre expertise scientifique a débouché sur l’élaboration de documents opérationnels pour le traitement des avis de tsunami dans le domaine terrestre et maritime et a permis d’établir une méthode de planification des évacuations pédestre. La méthode proposée est en cours d’application sur 60 communes littorales dans les Antilles Françaises. / The geo-dynamics of the Caribbean Sea area, particularly due to the presence of subduction zones and numerous volcanic faults is prone to the generation of tsunami's. Historical knowledge of this phenomenon in the region, coupled with recent modeling results, confirms this potential. The amplitudes of the modeled waves approaching the coast came close to 10m in some scenarios. The tsunami is a threat to the entire coastline of the Caribbean Sea. Human, structural and strategic installations, which are focused heavily on the coast, are particularly vulnerable to this phenomenon, especially in the Caribbean where the associated risk is very high. Today, at a regional level, a tsunami warning system is effective. However, there are no plans to guide the local authorities in their decision making to keep their population safe. At best they are very general, notably in the Antilles. So that we can anticipate their needs, we accompanied the operational planning of crisis management for the alert phases and the temporary evacuation of people on land and the security procedures for ships at sea. This initiative, undertaken on different levels, based on a geographical and integrated approach to the management of tsunami crisis, is at the interface of knowledge between scientific and operational domain. Our scientific expertise has led to the development of operational documents for the application of the tsunami warning on land and sea. It has helped to establish a method of pedestrian evacuation planning. The proposed method is already being implicated in 60 coastal municipalities in the French Antilles.

Several laterally extensive candidate tsunami deposits are preserved along coastlines facing the eastern Java Trench, indicating it has experienced mega-thrust earthquakes in the past. We investigated 37 coastal sites in Bali, Lombok, Sumba and Timor islands, many of which preserve course sand and pebble layers that overlie sharp basal contacts with scour marks into the mud, fine upward in grain size, and have bimodal grain size distributions. Other unique features are the common occurrence of marine fossils and concentrations of heavy minerals. The occurrence of these high-energy deposits interlayered with clay-rich units indicates the coarse clastics are anomalous because they were deposited in what is normally a very low-energy depositional environment. The lateral extent and paucity of thin, coarse clastic layers with marine organisms are inconsistent with local stream flood event, and the proximity to the equator of the sites diminishes the possibility of marine flood events from cyclones. The sparse, but consistent, the occurrence of at least two candidate tsunami deposits at depths of 1 and 2 meters over 950 km along the strike of the Java Trench may reveal that mega-thrust earthquakes have occurred there and generated giant tsunamis in the recent past. Five widely scattered imbricated boulder deposits are also found on Bali, Lombok, and Sumba. The boulders consist of slabs of hardpan up to 2.5 m in length and 80 cm thick that was torn from a near-shore seabed and stacked on top of one another. Some of the boulders were carried over the erosional coastal bank and deposited up to 100 meters inland. Comparisons with imbricated boulder ridges formed during the 1994 tsunami in east Java indicate that these deposits are from one or multiple tsunamis sourced by the Java Trench. Experiments in effective ways to communicate and implement tsunami disaster mitigation strategies have led us to train local communities about the 20-20-20 rule. If coastal communities experience more than 20 seconds of shaking from an earthquake, even if it is not intense, they should evacuate the coast. The time delay between the earthquake and arrival of tsunami waves is around 20 minutes, which is the time window for evacuation. Some tsunami waves may be as high as 20 meters, which is the target elevation for evacuation. Adopting the 20-20-20 rule could save thousands of lives throughout the region, especially in Bali where nearly 1 million people inhabit likely tsunami inundation zones.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第20040号 / 地環博第156号 / 新制||地環||31(附属図書館) / 33136 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)准教授 小林 広英, 教授 岡﨑 健二, 准教授 SINGER JANE / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

Recent tsunami events have inflicted devastating damage to coastal communities. Existing design standards provide a certain level of evaluation of tsunami effects such that critical infrastructure can be designed to resist tsunamis. Tsunami momentum flux, used to design structures is a function of water level height and velocity of tsunami bores. Understanding tsunamis and developing mitigation measures is essential. So far, some mitigation measures have been suggested, and to improve them, further investigations are required. The design of tsunami inundation effects mitigation canals is one of the suggested solutions which has received limited attention. The first objective of this study was to investigate the effects of a rectangular canal on the hydrodynamics of turbulent bores before and after the canal by conducting a series of physical experiments. A dam-break wave was used to simulate the tsunami-like turbulent waves passing over a smooth and horizontal surface, in the presence and/or absence of a canal. Three canal water depths were used to model shallow, moderate, and deep conditions, and three canal widths were also selected to model narrow to wide conditions while the dam break waves were generated from three different impoundment depths in a reservoir located upstream of the canal. The dam-break wave propagation over a horizontal, dry, and smooth bed revealed four regimes describing the variations of bore height with time. The time to reach the maximum bore height and the quasi steady-state regime were correlated with each impoundment depth and an empirical formulation was proposed to estimate the onset of the quasi steady-state flow. The maximum bore heights measured before and after the mitigation canal location were approximately 40 % and 50 % respectively, higher compared with those recorded in the corresponding tests without the presence of a canal. The second objective of this study was to experimentally investigate the effects of canal depth on the time history of bore height and its velocity. The experimental results were used for calibration and validation of a developed numerical model. The rapid release of an upstream impoundment water depth was employed to generate a bore analogous to a tsunami-induced inundation. The time histories of wave heights and velocity were measured upstream and downstream of the canal. The recorded time-series of the water surface levels and velocities were compared with the simulation results and good agreement was found between experimental and numerical water surface profiles using a Root Mean Square Error (RMSE) and the Relative Error. Three turbulence models:, namely the standard k-ε, the Realizable k-ε, and the RNG k-ε were tested, and it was found that all turbulence models perform well but the standard k-ε model provided satisfactory accuracy. The velocity contour plots for shallow, medium, and deep mitigation canals showed the formation and evolution of jets of different characteristics. The energy dissipation and air bubble entrainment of the tsunami bore, as it plunged into a canal, increased as the canal depth increased, and the jet flow of the maximum bore velocity decreased with increased canal depth. It was found that the eye of the vortex in the canal moved steadily in the downstream direction. Generally, the bore fully plunged almost nearly into the middle of the canal and started to divide into two small vortices. The third objective of this study dealt with a sequence of numerical experiments conducted to investigate the impact of mitigation canals on the hydrodynamics of a tsunami-like turbulent bore moving across a flat bed. The effects of mitigation canal depth and its orientation on the reduction of maximum specific momentum and energy of turbulent bores crossing over it were investigated numerically. Variations in the ratio between the downstream and upstream maximum specific momentum and mean flow energy decreased as the canal depth increased, and the time history of the mean flow energy over a canal with a rectangular endwise profile revealed that the canal depth affects the jet stream of the maximum mean flow energy. As the canal depth increased, the period of time needed to dissipate the area of the jet stream with the maximum turbulent kinetic energy, vorticity, and energy dissipation rate decreased. Both the angled and perpendicular to flow direction canals caused the maximum specific momentum and energy of the turbulent bore to decrease downstream of the canal. The specific momentum and energy achieved their highest values for a canal orientation of 45º. The greatest reductions in maximum specific momentum for turbulent bores over canals with different depths and orientations were achieved for 𝜃 = 30°.

Tsunami action had resulted in negative impacts in many ways, it had resulted in great changes to coastal areas, especially in terms of physical change to the coastal landscape, affected on economy, loss of life and physical damage to property. After the devastation, hotel bookings in the island were dropped, people have lost their jobs and some small-scale tourism businesses have got the hardest time as well. Some lifestyle entrepreneurs felt hopeless and have given up on doing business, which resulted to their businesses had to be closed because they were unable to access financial resources and did not have budget to restart their businesses again. Some might take longer time to rehabilitate their firms due to various limitations and conditions. While some have to fight back and develop their firms by turning crisis into opportunity and taking advantage of the crisis. This research is made in order to study and examine the impacts of and the recovery to the 2004 December tsunami disaster in Phuket, especially to small tourism businesses in Karon beach, which will be described through a disaster management model. The goal of this research is to study how the tsunami has affected on small firms and how they performed in order to rehabilitate their businesses, and even how they have been working and cooperating with the local government to draw back tourists to the destination.