Development Of Tsunami Warning System Research Articles

An Investigation on Multi-Buoy Inversion Method for Tsunami Warning System in South China Sea

The key technologies for the development of tsunami warning system include the establishment of tsunami database and inversion method for evaluating source parameters of earthquake by monitored wave data. A tsunami model based on the shallow water equations is adopted to simulate the 2011 Tohoku tsunami to validate the numerical model of generation and propagation of tsunami. The numerical results match well with measured data by DART buoys in terms of the wave height and the arrival time of the tsunami. For the potential earthquake source in the Manila Trench, the numerical model is used to compute the elementary wave fields triggered by unit sources of potential tsunami source with unit slip. Using the tsunami database derived by the elementary wave fields, an inversion method for plate slip based on multi-buoy measurements is applied to compute the time series of surface elevation at the given locations around the coasts in the South China Sea region. Through numerical simulations and multi-buoy inversion computation, the inversed time series of wave profile induced by earthquakes with the magnitudes Mw= 8.0, 8.5, 8.8, 9.35 are obtained. The comparisons of the inversion results and direct simulation data show good agreement. It turns out that, the multi-buoy inversion method works well and, according to the numerical results, deploying one or two buoys along the west side of the Manila Trench is necessary to provide tsunami warning information for the west coasts in the South China Sea. It is suggested that we should deploy one buoy between the south part of Taiwan and the north end of the Manila Trench subduction zone so that we could obtain a good predicted wave height at the south part of Taiwan by the multi-buoy inversion method.

Development of tsunami early warning systems and future challenges

Abstract. Fostered by and embedded in the general development of information and communications technology (ICT), the evolution of tsunami warning systems (TWS) shows a significant development from seismic-centred to multi-sensor system architectures using additional sensors (e.g. tide gauges and buoys) for the detection of tsunami waves in the ocean. Currently, the beginning implementation of regional tsunami warning infrastructures indicates a new phase in the development of TWS. A new generation of TWS should not only be able to realise multi-sensor monitoring for tsunami detection. Moreover, these systems have to be capable to form a collaborative communication infrastructure of distributed tsunami warning systems in order to implement regional, ocean-wide monitoring and warning strategies. In the context of the development of the German Indonesian Tsunami Early Warning System (GITEWS) and in the EU-funded FP6 project Distant Early Warning System (DEWS), a service platform for both sensor integration and warning dissemination has been newly developed and demonstrated. In particular, standards of the Open Geospatial Consortium (OGC) and the Organization for the Advancement of Structured Information Standards (OASIS) have been successfully incorporated. In the FP7 project Collaborative, Complex and Critical Decision-Support in Evolving Crises (TRIDEC), new developments in ICT (e.g. complex event processing (CEP) and event-driven architecture (EDA)) are used to extend the existing platform to realise a component-based technology framework for building distributed tsunami warning systems.

Anatomy of Historical Tsunamis: Lessons Learned for Tsunami Warning

Tsunamis are high-impact disasters that can cause death and destruction locally within a few minutes of their occurrence and across oceans hours, even up to a day, afterward. Efforts to establish tsunami warning systems to protect life and property began in the Pacific after the 1946 Aleutian Islands tsunami caused casualties in Hawaii. Seismic and sea level data were used by a central control center to evaluate tsunamigenic potential and then issue alerts and warnings. The ensuing events of 1952, 1957, and 1960 tested the new system, which continued to expand and evolve from a United States system to an international system in 1965. The Tsunami Warning System in the Pacific (ITSU) steadily improved through the decades as more stations became available in real and near-real time through better communications technology and greater bandwidth. New analysis techniques, coupled with more data of higher quality, resulted in better detection, greater solution accuracy, and more reliable warnings, but limitations still exist in constraining the source and in accurately predicting propagation of the wave from source to shore. Tsunami event data collected over the last two decades through international tsunami science surveys have led to more realistic models for source generation and inundation, and within the warning centers, real-time tsunami wave forecasting will become a reality in the near future. The tsunami warning system is an international cooperative effort amongst countries supported by global and national monitoring networks and dedicated tsunami warning centers; the research community has contributed to the system by advancing and improving its analysis tools. Lessons learned from the earliest tsunamis provided the backbone for the present system, but despite 45 years of experience, the 2004 Indian Ocean tsunami reminded us that tsunamis strike and kill everywhere, not just in the Pacific. Today, a global intergovernmental tsunami warning system is coordinated under the United Nations. This paper reviews historical tsunamis, their warning activities, and their sea level records to highlight lessons learned with the focus on how these insights have helped to drive further development of tsunami warning systems and their tsunami warning centers. While the international systems do well for teletsunamis, faster detection, more accurate evaluations, and widespread timely alerts are still the goals, and challenges still remain to achieving early warning against the more frequent and destructive local tsunamis.

Numerical Modeling of Generation and Propagation of Tsunami Waves along the Southern Coast of Iran

The main goal of this study is to increase the software capabilities of Iran towards the development of a tsunami warning system for its southern coast bordering the Indian Ocean. The devastating tsunami of 26 December 2004 in the Indian Ocean region emphasized the necessity for development of tsunami warning systems for the world’s vulnerable coastlines, especially for those neighboring the Indian Ocean. Studies showed that there are two main tsunamigenic zones in the Indian Ocean region, namely the Sumatra subduction zone in the east and the Makran subduction zone at the northwest of this ocean. The Makran subduction zone is located offshore Iran and Pakistan and produced some destructive tsunamis in the past. The most recent tsunami in the Makran region occurred on 28 November 1945 which claimed more than 4000 lives along the coasts of Iran, Pakistan, Oman and India. As the southern coast of Iran is at risk of tsunami from the Makran subduction zone, Iran is committed to work towards the development of a tsunami warning system, and to cooperate with the countries in the region in this field. All activities towards the development of a tsunami warning system can be classified into two categories: 1) hardwares like tsunameters, tide gauges, seismic networks, and etc., and 2) softwares. Numerical modeling of tsunami is among the second group and is a vital part of any tsunami warning system. Here, we discuss the modeling of tsunami generation and propagation. At first, the algorithm for tsunami generation modeling is presented and then, the generation phase of a possible tsunami in the region was modeled. The results of generation modeling were compared with international experiences. In the next section, the propagation of tsunami was modeled using a well-validated international numerical model for long waves. Results of the tsunami generation modeling showed that in the case of an earthquake with a moment magnitude of 8, the maximum vertical uplift of the seafloor will be about 1.5 m, and an area with the dimensions of 150 and 250 km will be deformed due to the earthquake. Tsunami propagation modeling showed that the first tsunami waves will hit the nearest coastline within 15-20 min after the earthquake. The maximum tsunami wave height was estimated about 3 m. It is showed that how the results of the numerical modeling of tsunami can help to develop a tsunami warning system. Our preliminary investigation shows that at least 891 case-scenarios should be simulated to develop the tsunami warning system in the Makran region.

History and Challenge of Tsunami Warning Systems in Japan

History of development of Tsunami Warning System in Japan started in 1952 after the tsunami warning/forecast system formulated at Sanriku is introduced. The system estimated the earthquake epicenter and magnitude, and issued the forecast by referring to the tsunami forecast maps. In 1999, the Japan Meteorological Agency (JMA) has introduced the computer-aided simulation system for quantitative tsunami forecasting, in which tsunami arrival times and heights are simulated and stored in the database for forecasting tsunamis. The JMA has been further updating the system and now can issue the forecast 2 to 3 minutes after occurrence of an earthquake. By reviewing the response of the people for past tsunamis forecasting and information in an example case of the 2006 Kurile Earthquake tsunami, we discuss the issues such as accuracy, detail and canceling in order to improve the system.

Performance of Lifelines in Banda Aceh, Indonesia, during the December 2004 Great Sumatra Earthquake and Tsunami

The 26 December 2004 earthquake and tsunami significantly affected lifelines in Banda Aceh: (a) the water system sustained almost no damage due to shaking, but it had breaks at almost all aboveground stream crossings affected by the tsunami; (b) a waste disposal plant 1 km inland was estroyed by the tsunami; (c) electric utilities were not affected by shaking but were generally destroyed when impacted by the tsunami, and a floating generation barge was carried several kilometers inland; (d) a 70- m steel telecommunications tower at Lho Nga was destroyed by the tsunami; (e) the fishing port at Banda Aceh was totally destroyed, while the deep-water port at Kreung Raya (oil and dry cargo) lost half its piping and 3 of 9 oil tanks; (f) the airport at Banda Aceh is inland and had minor shaking damage to the control tower; and (g) one fire was reported on 26 December due to the earthquake. Significant lessons are (a) since the potential for this event was well known, the global earthquake community should better inform populations and decision makers; (b) urban master planning and building codes should include tsunami design as a standard and significant criterion; (c) the needs of lifeline operators should be considered in the design and development of tsunami warning systems; (d) building and other design codes should include tsunami design as a standard loading; and (e) extrapolation of the experience in this event to other situations is required.