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This paper presents the tsunami warning tools, which are used for the estimation of the seismic source parameters. These tools are grouped under a method called Preliminary Determination of Focal Mechanism_2 ( PDFM2), that has been developed at the French Polynesia Warning Center, in the framework of the $$SEISCOMP3$$ system, as a plug-in concept. The first tool determines the seismic moment and the focal geometry (strike, dip, and slip), and the second tool identifies the 'tsunami earthquakes' (earthquakes that cause much bigger tsunamis than their magnitude would imply). In a tsunami warning operation, initial assessment of the tsunami potential is based on location and magnitude. The usual quick magnitude methods which use $$P$$ waves, work fine for smaller earthquakes. For major earthquakes these methods drastically underestimate the magnitude and its tsunami potential because the radiated energy shifts to the longer period waves. Since French Polynesia is located far away from the subduction zones of the Pacific rim, the tsunami threat is not imminent, and this luxury of time allows to use the long period surface wave data to determine the true size of a major earthquake. The source inversion method presented in this paper uses a combination of surface waves amplitude spectra and P wave first motions. The advantage of using long period surface data is that there is a much more accurate determination of earthquake size, and the advantage of using P wave first motion is to have a better constrain of the focal geometry than using the surface waves alone. The $$PDFM2$$ method routinely gives stable results at $$T_0 + 45$$ minutes, with $$T_0$$ being the origin time of an earthquake. Our results are then compared to the Global Centroid Moment Tensor catalog for validating both the seismic moment and the source geometry. The second tool discussed in this paper is the slowness parameter $$\theta,$$ and is the energy-to-moment ratio. It has been used to identify tsunami earthquakes, which are characterized by having unusual slow rupture velocity and release seismic energy that has been shifted to longer periods and, therefore, have low $$\theta$$ values. The slow rupture velocity would indicate weaker material and bigger uplift and, thus, bigger tsunami potential. The use of the slowness parameter $$\theta$$ is an efficient tool for monitoring the near real-time identification of tsunami earthquakes. [ABSTRACT FROM AUTHOR]

The destructive Pacific Ocean tsunami generated off the east coast of Honshu, Japan, on 11 March 2011 prompted the West Coast and Alaska Tsunami Warning Center (WCATWC) to issue a tsunami warning and advisory for the coastal regions of Alaska, British Columbia, Washington, Oregon, and California. Estimating the length of time the warning or advisory would remain in effect proved difficult. To address this problem, the WCATWC developed a technique to estimate the amplitude decay of a tsunami recorded at tide stations within the Warning Center's Area of Responsibly (AOR). At many sites along the West Coast of North America, the tsunami wave amplitudes will decay exponentially following the arrival of the maximum wave ( Mofjeld et al., Nat Hazards 22:71-89, ). To estimate the time it will take before wave amplitudes drop to safe levels, the real-time tide gauge data are filtered to remove the effects of tidal variations. The analytic envelope is computed and a 2 h sequence of amplitude values following the tsunami peak is used to obtain a least squares fit to an exponential function. This yields a decay curve which is then combined with an average West Coast decay function to provide an initial tsunami amplitude-duration forecast. This information may then be provided to emergency managers to assist with response planning. [ABSTRACT FROM AUTHOR]

The source region of the catastrophic Tohoku tsunami of 11 March 2011 was not far from the Russian Far East coast. The Sakhalin Tsunami Warning Center at Yuzhno-Sakhalinsk issued an Alert for threatened coasts of the Kuril Islands and Kamchatka; the observed tsunami heights were up to 2-2.5 m along the Pacific coast of the Kuril Islands. The tsunami was clearly recorded by a number of coastal tide gauges and by deep-ocean bottom pressure stations located in the vicinity of the Kuril Islands, as well as by the Russian open-ocean DART station 21401, located eastward from the South Kuril Islands. The data from other DART stations, in particular those located near Japan and the Aleutian Islands, were used for comparison. The records from these instruments were used to estimate the major characteristics of the tsunami waves, including arrival times, maximum heights, durations of the signal and main wavelength periods, as well as for comparison with the results of numerical modelling. In contrast to deep-sea stations where the first waves were the highest, at Russian coastal sites the highest waves occurred several hours after the arrival of the first tsunami wave. Further analysis indicated significant differences in spectral characteristics of tsunami waves propagating eastward toward North America and those directed in the northeast direction towards the Russian Far East. The main peaks of the eastward propagating tsunami waves were relatively high-frequency (periods ranging from 6-8 to 15-20 min), while those propagating in the northeast direction were mainly low-frequency (ranging from 25-40 to 60-80 min). Additionally, pronounced spectral peaks with similar long periods were found in the 'middle-field' records at Hanasaki (on the northeastern coast of Hokkaido Island), at Yuzhno-Kurilsk (Kunashir Island) and at Malokurilsk (Shikotan Island). At remote stations, the resonant periods associated with local topographic features were predominant in the spectra. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Deep-sea tsunami measurements play a major role in understanding the physics of tsunami wave generation and propagation, and in the creation of an effective tsunami warning system. The paper provides an overview of the history of tsunami recording in the open ocean from the beginning (about 50 years ago) to the present day. It describes modern tsunami monitoring systems, including the Deep-ocean Assessment and Reporting of Tsunamis (DART), innovative Japanese bottom cable projects, and the NEPTUNE-Canada geophysical bottom observatory. The specific peculiarities of seafloor longwave observations in the deep ocean are discussed and compared with those recorded in coastal regions. Tsunami detection in bottom presure observations is exemplified based on analysis of distant (22000 km) records of the 2004 Sumatra tsunami in the northeastern Pacific. [ABSTRACT FROM AUTHOR]

The March 11, 2011, megaquake caused a catastrophic tsunami recorded throughout the Pacific. This paper presents an analysis of the sea-level records obtained from deep-water tsunami meters (DART and NEPTUNE). To evaluate the effect of the sea-level oscillations' decay, a statistical analysis of observations and numerical modeling of tsunami generation and propagation have been conducted. The main goal is to uncover physical mechanisms of the tsunami wave field formation and evolution at scales up to tens of thousands of kilometers in space and a few days in time. It is shown that the tsunami lifetime is related to the wave-energy diffusion and dissipation processes. The decay time of the variance of the tsunami-generated level oscillations is about 1 day. Multiple reflections and scattering by irregularities of the bottom topography make the field of the secondary tsunami waves stochastic and incoherent: the distribution of the wave energy in the ocean reaches a statistical equilibrium in accordance with the Rayleigh-Jeans law of equipartition of the wave energy per degree of freedom. After the tsunami front has passed, the secondary-wave energy density turns out to be inversely proportional to the water depth. [ABSTRACT FROM AUTHOR]

Two remote tsunamis were recorded on the Pacific coast of Russia: a relatively weak Samoan tsunami of September 29, 2009 and a much stronger Chilean tsunami of February 28, 2010. In the area of the South Kuril Islands, records were obtained using autonomous bottom pressure gauges of the Institute of Marine Geology and Geophysics (IMGG). Additionally, for the oceanic coast of the Kamchatka Peninsula, Paramushir, and Bering Islands we used data transmitted from coastal tide gauges of the Russian Tsunami Warning Service (TWS). The maximum trough-to-crest heights of the Samoan tsunami were about 30-40 cm, and were recorded about 3 h after the first tsunami arrival. The maximum Chilean tsunami trough-to-crest wave heights were 218 cm at Severo-Kurilsk, 187 cm at Tserkovnaya Bay (Shikotan Island), and 140 cm at Khodutka Bay (Kamchatka Peninsula). The time between first and maximum waves reached 4 h. Strong sea level oscillations for both events range for a long time: about 15-17 h. The Samoan tsunami induced high-frequency oscillations; a considerable increase in spectral energy in the tsunami spectrum was observed at periods of 4-20 min. In contrast, the Chilean tsunami induced low-frequency oscillations; the dominant periods were 30-80 min. A probable reason for these differences is the different extensions of the source areas (the Chilean source was much larger than the Samoan source) and the different energy radiation directions from the sources. Local topography resonant effects were the main reason of well-expressed peaks in power spectra in different areas: with a period of 10 min (Khodutka Bay), 19-20 min (Malokurilskaya and Tserkovnaya bays), 29 min (Krabovaya Inlet), and 43 min (Avachinskaya Guba and Nikolskoe). [ABSTRACT FROM AUTHOR]

We propose a novel approach for near-field tsunami detection, specifically for the area near the city of Padang, Indonesia. Padang is located on the western shore of Sumatra, directly across from the Mentawai segment of the Sunda Trench, where accumulated strain has not been released since the great earthquake of 1797. Consequently, the risk of a major tsunamigenic earthquake on this segment is high. Currently, no ocean-bottom pressure sensors are deployed in the Mentawai basin to provide a definitive tsunami warning for Padang. Timely warnings are essential to initiate evacuation procedures and minimize loss of human life. Our approach augments existing technology with a network of underwater sensors to detect tsunamis generated by an earthquake or landslide fast enough to provide at least 15 minutes of warning. Data from the underwater sensor network would feed into existing decision support systems that accept input from land and sea-based sensors and provide warning information to city and regional authorities. [ABSTRACT FROM AUTHOR]

The Pacific ENSO Applications Center (PEAC) was established in August 1994 as a multi-institutional partnership to conduct research and produce information products on climate variability and impacts related to the El Niño-Southern Oscillation climate cycle for the U.S.-Affiliated Pacific Islands (USAPI). The name of the center was changed to Pacific ENSO Applications Climate (PEAC) Center in 2007. Over the years, the PEAC Center effectively provided advanced warning as part of the hazard management program for the small island countries in the USAPI region. The primary focus of this paper is to synthesize the overall hazard management activities of the PEAC Center by visiting various aspects of the historical and current operational framework, including i) forecasting, ii) interpretation and message formulation, iii) warning preparation and dissemination, iv) responses and feedback, and v) review and analysis. The forecast, warning, and response experience of PEAC can help small island countries in the Pacific develop adaptation strategies for longer time-scale climate variability and change. [ABSTRACT FROM AUTHOR]

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 multisensor 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. [ABSTRACT FROM AUTHOR]

Real-time detection of a tsunami on instrumental sea-level records is quite an important task for a Tsunami Warning System (TWS), and in case of alert conditions for an ongoing tsunami it is often performed by visual inspection in operational warning centres. In this paper we stress the importance of automatic detection algorithms and apply the TEDA (Tsunami Early Detection Algorithm) to identify tsunami arrivals of the 2011 Tohoku tsunami in a real-time virtual exercise. TEDA is designed to work at station level, that is on sea-level data of a single station, and was calibrated on data from the Adak island, Alaska, USA, tide-gauge station. Using the parameters' configuration devised for the Adak station, the TEDA has been applied to 123 coastal sealevel records from the coasts of the Pacific Ocean, which enabled us to evaluate the efficiency and sensitivity of the algorithm on a wide range of background conditions and of signal-to-noise ratios. The result is that TEDA is able to detect quickly the majority of the tsunami signals and therefore proves to have the potential for being a valid tool in the operational TWS practice. [ABSTRACT FROM AUTHOR]

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The study on tsunami responses was conducted in order to present the activities of land uses/land covers after the December 2004 Indian Ocean tsunami, and to prepare tsunami related facilities in Phuket Island, Thailand. Multi-temporal analysis on ASTER scenes acquired pre tsunami (Mar, 2004) and post tsunami (2005 and 2010) were classified into 6 main land uses/land covers," Agriculture, Beach, Built-up, Forest, Miscellaneous and Water body. It was observed that the tourist facilities in famous tourist beaches, such as Patong and Kamala, recovered by about 80% at the end of 2005. Most of the increased built-up areas in 2010 were located outside the tsunami inundated zone. Following the 2004 Indian Ocean tsunami, the tsunami warning system and related facilities, such as the Deep-ocean Assessment and Reporting of Tsunamis (DART), broadcasting towers, wave protection barriers and tsunami shelter or evacuation sites have been set up. In addition, bi-lingual (Thai-English) tsunami related notice boards and maps were placed since 2005. After the disaster, the tsunami awareness and evacuation procedures have annually trained and practiced with local residents, tourists and disaster related agencies in Phuket. [ABSTRACT FROM AUTHOR]

The article discusses the 2011 earthquake in Japan which produced the largest ever recorded displacement of the Earth's crust. Topics discussed include the theory of plate tectonics and the distribution of earthquakes along plate boundaries, and the release and recording of energy in the form of seismic waves. Also included is information about tsunami and earthquake warning systems.

Indonesia has an Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth < 70 km and magnitude > 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purpose of this study is to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor Sea, Banda Sea, Arafura Sea and Pacific Ocean using a direct procedure and software developed Lomax and Michelini for rapid assessment of earthquake tsunami potential by deriving two simple measures from vertical component broadband P-wave velocity record. The first is the high-frequency apparent rupture duration, Tdur which may be related to can be related to the critical parameters rupture length (L), depth (z), and shear modulus (μ). The second is a confirmation of the earlier finding by Lomax and Michelini, namely that the rupture duration has a stronger influence to generate tsunami than Mw and Depth. We analyzed at least 510 vertical seismogram recorded by GEOFON-IA and IRIS-DMC networks. Our analysis shows that the seismic potency, LWD, which is more obviously related to capability to generate a tsunami than former. The larger Tdur the larger is the seismic potency LWD because Tdur is proportional to L/vr (with vr -- rupture velocity). We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 3 to 8 min after the P-onset. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: Niuatoputapu Island, Tonga, lies at the northern end of the Tongan trench, approximately 190km east of the epicentre of the earthquake that produced the 29th September, 2009, South Pacific tsunami. The tsunami inundated 46% of the land area of Niuatoputapu, maximum inundation of 1100m occurred along the southeastern coastline of the island while inundation distances in the villages were typically 200–500m. Flow direction indicators show that the strongest flow of the tsunami came from a northeast to east direction; the tsunami refracted around the northern and southern points of the island and inundated the west coast from variable directions. Maximum runup of 4.7m above mean sea level was recorded at the village of Falehau in the northwest of Niuatoputapu. The flow height of the tsunami reached a maximum of 16.9m above mean sea level at Toma, on the southeast coast of Niuatoputapu. Flow heights were typically between 8 and 15m along the eastern, uninhabited coastline of Niuatoputapu and decreased by about half, to between 4 and 7m above mean sea level along the western, inhabited coastline. With no prior knowledge or education to prompt self-evacuation, its remote location hampering recovery efforts, and high tsunami flow heights, Niuatoputapu suffered severe tsunami impacts in the social, economic and physical realms. We discuss aspects of the tsunami impacts and the implications of the event on our understanding of South Pacific tsunami hazard and how tsunami hazards can be managed on small, remote islands. [Copyright &y& Elsevier]

The Chilean territory has an extensive coastline -about 80.000 km of coast including the territory of its islands — which is an important fact to consider in the event of the occurrence of a tsunami. The Chilean authorities, fully aware of the vast maritime territory, have developed a tsunami warning system. This system constitutes a state responsibility, and its control has been entrusted to the national emergency office —Ministry of Interior— (ONEMI) and hydrographic and oceanographic service of Chilean navy (SHOA). This article deals with experiences carried out in order to activate the warning systems, generating fictional telluric events and or historical telluric events capable of triggering tsunami occurrences. It also proposes a working hypothesis that will allow monitoring the response of the state agencies, through the procedures established by law in the Republic of Chile. Our research delivers results that allow us to affirm that there are areas for hypothetical events that could generate tsunamis in which the to carry out this research we have used a software called STLAT based on simplified equations of the propagation of a tsunami wave, which has allowed us to get quick results. We have also carried out tests with official data which have shown that the alarm system was not able to respond appropriately to the 8.4 M Atico event that occurred in Peru in 2001. [ABSTRACT FROM AUTHOR]

A review of historical data for Hawaii reveals that significant tsunamis have been reported for only four of twenty-six potentially tsunamigenic earthquakes from 1868 through 2009 with magnitudes of 6.0 or greater. During the same time period, three significant tsunamis have been reported for substantially smaller earthquakes. This historical perspective, the fact that the last significant local tsunami occurred in 1975, and an understandable preoccupation with tsunamis generated around the margins of the Pacific, all combine to suggest apparent deficiencies in: (1) personal awareness of what to do in the event of a possible local tsunami; (2) the distribution of instrumentation capable of providing rapid confirmation that a local tsunami has been generated; and (3) the subsequent issuance of timely warnings for local tsunamis. With these deficiencies, far more lives may be lost in Hawaii due to local tsunamis than will result from tsunamis that have originated along the margins of the Pacific. Similar deficiencies may exist in other areas of the world threatened by local tsunamis. [ABSTRACT FROM AUTHOR]

Abstract: The 29 September 2009 South Pacific tsunami reached the islands of Futuna and Alofi, 650km to the west of its origin, between 7 and 7:20 am on 30 September, local time. No warning was issued. We measured run-up heights and inundation distances at 41 sites around the islands. The worst impact (4.5m run-up; 85m inundation; 3.8m flow depth) was observed on Alofi''s NW beach. On Futuna, maximum run-ups of 4.4m on the eastern tip and 4.3m on the NW tip of the island are associated with maximum inundations of 95 and 72m, respectively. A flow depth of 2.2m was inferred on the NE tip. The tsunami arrived as a drawdown of water with the reef exposed well below the lowest tides. It was followed by two positive waves of similar amplitude, ca. 4min apart. Damage was mainly limited to salt-burnt vegetation and sediments deposited at the coast. There were no casualties, but a significant disaster was avoided because the tsunami arrived in the early morning at close to low tide. This event, together with a small tsunami triggered by a local earthquake in 1993 and an oral legend about a destructive wave, indicate that the hazard is high for the 4500 inhabitants of Futuna who live on the low-lying, narrow coastal strip. The 70min that the tsunami took to reach the island provided sufficient time for a warning to be issued, but this was not done. [Copyright &y& Elsevier]

Abstract: In order to establish a tsunami alert system in New Caledonia in April 2008, the French Secretary of State for Overseas Affairs, with the aid of the UNESCO French Commission, mandated an investigation to build a more complete record of the most recent tsunamis. To complete this task, a call for witnesses was broadcast through various media and in public locations. These witnesses were then interviewed onsite about the phenomenon they had observed. Previous witness reports that had been obtained in the last few years were also used. For the most recent events, various archives were consulted. In total, 18 events were documented, of which 12 had not been previously mentioned in past work. These results confirm an exposure to a hazard of: (1) local origin (the southern part of the Vanuatu arc) with a very short post-seismic delay (<30min) before the arrival of wave trains; (2) regional origin (Solomon Islands arc, northern part of the Vanuatu arc) with a delay of several hours; and (3) an exposure to trans-oceanic tsunamis (Kamchatka 1952, South Chile 1960, Kuril Islands 2006, North Tonga 2009), unknown until today. These results highlight the necessity for New Caledonia to adopt an alert system, coupled with ocean tide gauges, that liaises with the main alert system for the Pacific (Pacific Tsunami Warning Center), and brings to light the importance of establishing a prevention campaign. [Copyright &y& Elsevier]

An optimal and integrative tsunami warning system is introduced that takes full advantage of remote sensing and geographical information systems (GIS) in monitoring, forecasting, detection, loss evaluation, and relief management for tsunamis. Using the primary impact zone in Banda Aceh, Indonesia as the pilot area, we conducted three simulations that showed that while the December 26, 2004 Indian Ocean tsunami claimed about 300,000 lives because there was no tsunami warning system at all, it is possible that only about 15,000 lives could have been lost if the area had used a tsunami warning system like that currently in use in the Pacific Ocean. The simulations further calculated that the death toll could have been about 3,000 deaths if there had been a disaster system further optimized with full use of remote sensing and GIS, although the number of badly damaged or destroyed houses (29,545) could have likely remained unchanged. [ABSTRACT FROM AUTHOR]

The magnitude 9.5 earthquake on 22 May 1960 in southern Chile was the largest instrumentally recorded earthquake in the 20th century. It generated a tsunami that swept the shores of Chile and radiated out across the Pacific, with the major loss of life in Chile and, despite warnings being issued, in both Hawai'i and Japan. The absence of a Pacific-wide tsunami warning system at the time meant that the tsunami struck New Zealand without an official warning being issued. Fortunately, there was no loss of life despite widespread damage to coastal facilities. A large aftershock occurred in Chile 3 days later (25 may) and fears about a tsunami from this event resulted in the broadcasting of a nationwide warning on radio in New Zealand. Newspapers of the day reported that thousands of people around the country were evacuated, making this the largest and most widespread evacuation in New Zealand's history. Almost the entire population of Whitianga, Waihi Beach, Whakatane, Ohope, and Opotiki were moved to high ground for several hours and, in many other communities, people self-evacuated from coastal fringes. After the event, there was much discussion in the newspapers of the need to improve both warnings and public awareness of the hazard, and of the appropriate response to warnings. Over the 40 years from 1960 up to the 26 December 2004 Indian ocean tsunami, public awareness of New Zealand's tsunami risk and preparedness had waned. Since 2004, the renewed focus on tsunami has built on a range of improvements in emergency management policies and practices, and the lessons identified from the event paved the way for a number of new initiatives to get underway to enhance the New Zealand's tsunami warning capacity and capability. [ABSTRACT FROM AUTHOR]

Alberni Inlet is a long and narrow fjord adjacent to Barkley Sound on the Pacific Coast of Vancouver Island, Canada. Port Alberni, at the head of the inlet, was affected in 1964 by the largest Pacific tsunami waves in Canadian history. We use observations and results from two numerical models to investigate the resonant characteristics of the region and amplification of tsunami waves in Barkley Sound and Alberni Inlet. The first model (A) was forced at its open boundary with a stationary autoregressive signal, similar to the observed background noise. The second model (B) used an initial sea-level deformation from a potential earthquake off California in the southern segment of the Cascadia Subduction Zone, producing transient tsunami waves. Spectral, cross-spectral and frequency-time ( f-t) analyses of the observations were used to examine the resonant properties and topographic response of the local area. The respective results show large admittance functions over a wide 0.5–0.9 cph frequency band, implying a low Q factor but high amplification of arriving waves. This unusual behavior is a result of two effects: A quarter-wave resonance of the system for its fundamental Helmholtz mode and amplification due to the narrowing of the channel cross section from Barkley Sound to Alberni Inlet. The model A numerical results agree favorably with the observations, indicating an energetic resonant mode at frequency of ~0.53 cph (112 min), with its nodal line located near the entrance to Barkley Sound and amplification factor value close to 12. The results from the tsunami propagation model (B) yield spectral characteristics similar to those from the model A and from the observations. The maximum tsunami current speed for this scenario is 2.4 ms−1 in Sproat Narrows, which divides Alberni Inlet into two parts, while the largest computed wave height is 1.6 m in the northern Alberni Inlet, in the area of Port Alberni. [ABSTRACT FROM AUTHOR]

Currently information used to describe sea-level stations (such as location, collection and transmission capabilities, operator identification, etc.) is distributed among databases held by multiple agencies, institutions and organizations. Such information could be used to support detection and warning. However, the Indian Ocean Tsunami of 26 December, 2004 made it clear that such information is not readily accessible, is difficult to use, and is often incomplete. In addressing this issue, agencies within the Pacific region are collaborating to develop a web service to expose station metadata enabling various types of real-time data mining client applications that support decision-making and strategic planning at Tsunami Warning Centers. Because information about sea levels has a broad range of applications, integration of this information in a way that is comprehensive, and enhances its access and use, would have a tremendous impact on lives and livelihoods. [ABSTRACT FROM AUTHOR]

The 2004 Indian Ocean tsunami caused an estimated 230,000 casualties, the worst tsunami disaster in history. A similar-sized tsunami in the Pacific Ocean, generated by the 1960 Chilean earthquake, commenced international collaborations on tsunami warning systems, and in the tsunami research community through the Tsunami Commission of International Union of Geodesy and Geophysics. The IUGG Tsunami Commission, established in 1960, has been holding the biannual International Tsunami Symposium (ITS). This volume contains selected papers mostly presented at the 22nd ITS, held in the summer of 2005. This introduction briefly summarizes the progress of tsunami and earthquake research as well as international cooperation on tsunami warning systems and the impact of the 2004 tsunami. Brief summaries of each paper are also presented. [ABSTRACT FROM AUTHOR]

Discusses the preparations of the government of New Zealand for the impact of tsunamis. Affiliation of the country with the International Co-ordination Group for the Tsunami Warning System in the Pacific; Basis of emergency management in the country; Ways to mitigate tsunami risk; National tsunami initiatives in the country.

Focuses on the detection and early warning systems of tsunamis. Deployment of an experimental system called Deep-ocean Assessment and Reporting of Tsunamis (DART) in the Pacific Ocean by the U.S. National Oceanic and Atmospheric Administration in 1999, a component of the Tsunami Warning System, a cooperative venture of 26 states and countries that monitor seismic activity and tidal regimes throughout the Pacific Basin; Description of the system's operation; Capability of DART sensors to detect wave-height differences. INSET: TSUNAMIS - WHAT, HOW AND WHERE?.

A power-law scaling relationship describes tsunami runup heights at ten locations in Japan. Knowledge of the scaling law for tsunamis can be the basis for probabilistic forecasting of the size and number of future events and for estimating probabilities of extremely large events. Using tsunami runup data archived by the U.S. National Geophysical Data Center, we study ten locations where the tsunami record spans at least one order of magnitude in runup height and the temporal record extends back several decades. A power law or upper-truncated power law describes the cumulative frequency-size distribution of tsunami runup heights at all ten locations. Where the record is sufficient to examine shorter time intervals within the record, the scaling relationship for the shorter time intervals is consistent with the scaling relationship for the entire record. The scaling relationship is used to determine recurrence intervals for tsunami runup heights at each location. In addition to the tsunami record used to determine the scaling relationship, at some of the locations a record of large events (>5 m) extends back several centuries. We find that the recurrence intervals of these large events are consistent with the frequency predicted from the more recent record. For tsunami prone locations where a scaling relationship is determined, the predicted recurrence intervals may be useful for planning by coastal engineers and emergency management agencies. [ABSTRACT FROM AUTHOR]