Tsunami Science Research Articles

Tsunami event in Flores: literature review

<p class="Abstract"><span lang="EN-GB">The Flores Sea has experienced devastating earthquakes with magnitudes >7 over the past 30 decades. It can trigger a tsunami and provide important theoretical, experimental, and field information. The seismicity study stated that the island of Flores had experienced tsunamis during the pre-instrumental period (1815, 1818, 1820, and 1836) and the pre-instrumental period in 1992. This study discusses the development of tsunami research in Flores using a literature review approach. The data source comes from the Scopus database, with data analysis using VOSviewer. The search results obtained a total of 22 documents, with the result that the 1992 Flores earthquake became the main research topic and the beginning of the era of modern tsunami science</span><span lang="EN-GB">.</span></p>

The EU Center of Excellence for Exascale in Solid Earth (ChEESE): Implementation, results, and roadmap for the second phase

The EU Center of Excellence for Exascale in Solid Earth (ChEESE) develops exascale transition capabilities in the domain of Solid Earth, an area of geophysics rich in computational challenges embracing different approaches to exascale (capability, capacity, and urgent computing). The first implementation phase of the project (ChEESE-1P; 2018–2022) addressed scientific and technical computational challenges in seismology, tsunami science, volcanology, and magnetohydrodynamics, in order to understand the phenomena, anticipate the impact of natural disasters, and contribute to risk management. The project initiated the optimisation of 10 community flagship codes for the upcoming exascale systems and implemented 12 Pilot Demonstrators that combine the flagship codes with dedicated workflows in order to address the underlying capability and capacity computational challenges. Pilot Demonstrators reaching more mature Technology Readiness Levels (TRLs) were further enabled in operational service environments on critical aspects of geohazards such as long-term and short-term probabilistic hazard assessment, urgent computing, and early warning and probabilistic forecasting. Partnership and service co-design with members of the project Industry and User Board (IUB) leveraged the uptake of results across multiple research institutions, academia, industry, and public governance bodies (e.g. civil protection agencies). This article summarises the implementation strategy and the results from ChEESE-1P, outlining also the underpinning concepts and the roadmap for the on-going second project implementation phase (ChEESE-2P; 2023–2026).

“It’s something that I do every day.” Exploring interdisciplinarity and stakeholder engagement in tsunami science

Tsunamis are natural hazards that can have devastating societal impacts. While tsunamis cannot be prevented, their risk to coastal communities can be mitigated through targeted measures such as early warning, evacuation training or tsunami-aware spatial planning. The particularities of tsunamis–being rare events with high impact and a short yet operable time span for warning–structure the associated research approaches and sociotechnical innovations. In this paper, we explore interdisciplinary knowledge integration and stakeholder engagement in tsunami science based on interviews with researchers from various tsunami-related fields. We find that the interviewees’ academic identities are typically grounded in a disciplinary core, out of which they subsequently cross boundaries. For all respondents, however, it is a matter of course that becoming and being a member of the tsunami community includes the need to communicate across boundaries. Our results show that the idea of early warning unites the tsunami field. Notably, however, it is not the material technology but the political goal of effective early warning that holds an integrative function across disciplines. Furthermore, we find modelling to be seen as the “backbone of everything” tsunami-related, which in combination with visualisation techniques such as a global map of tsunami risks also serves to integrate stakeholders beyond the tsunami research community. Interviewees mention the interaction between scientists and engineers as the exemplary interdisciplinary collaboration in tsunami science. There were fewer examples of collaborations with social scientists, rendering this a demand rather than a lived reality in current tsunami science. Despite the widely shared view that stakeholder engagement is an important element of tsunami science, respondents emphasise the associated challenges and indicate that this practice is not yet sufficiently institutionalised.

Progress in Tsunami Science: Toward an Improved Integration of Hydrodynamical Modeling and Geomorphic Field Evidence

Risks posed by sea-level rise and cyclones are becoming more prevalent along the world’s coastlines. In recent years, tsunamis have had devastating impacts on communities in different ocean basins. Although storms and tsunamis can be clearly distinguished when they occur in the present, this does not apply to the past, from which only their traces in the form of sedimentary or geomorphologic features provide clues about their occurrence. Following a short review of research on tsunamis from the last decades, this study uses the example of coastal boulder deposits to highlight where knowledge gaps exist. This report focuses on the spatial distribution of sediment patterns and how these may provide clues to the transport processes. However, the history of these deposits and related sea-level records during the same time span must also be recorded and contextualized. Theoretical modeling results without including these parameters will remain fuzzy, if not inaccurate. This contribution points to the need for consideration of both data and nature’s reality (which are complementary and interdependent) in this field.

Towards the new Thematic Core Service Tsunami within the EPOS Research Infrastructure

Tsunamis constitute a significant hazard for European coastal populations, and the impact of tsunami events worldwide can extend well beyond the coastal regions directly affected. Understanding the complex mechanisms of tsunami generation, propagation, and inundation, as well as managing the tsunami risk, requires multidisciplinary research and infrastructures that cross national boundaries. Recent decades have seen both great advances in tsunami science and consolidation of the European tsunami research community. A recurring theme has been the need for a sustainable platform for coordinated tsunami community activities and a hub for tsunami services. Following about three years of preparation, in July 2021, the European tsunami community attained the status of Candidate Thematic Core Service (cTCS) within the European Plate Observing System (EPOS) Research Infrastructure. Within a transition period of three years, the Tsunami candidate TCS is anticipated to develop into a fully operational EPOS TCS. We here outline the path taken to reach this point, and the envisaged form of the future EPOS TCS Tsunami. Our cTCS is planned to be organised within four thematic pillars: (1) Support to Tsunami Service Providers, (2) Tsunami Data, (3) Numerical Models, and (4) Hazard and Risk Products. We outline how identified needs in tsunami science and tsunami risk mitigation will be addressed within this structure and how participation within EPOS will become an integration point for community development.

Introduction to “Sixty Years of Modern Tsunami Science, Volume 1: Lessons and Progress”

Twenty-three papers are included in this PAGEOPH topical issue “Sixty Years of Modern Tsunami Science, Volume I: Lessons and Progress”. The papers are grouped into four categories: historical tsunami events, studies on tsunami source models and case studies, tsunami hydrodynamics, and probabilistic tsunami hazard assessment and forecasting. Papers that reflect the current state of tsunami science and research are briefly introduced.

Editorial: From Tsunami Science to Hazard and Risk Assessment: Methods and Models

Editorial: From Tsunami Science to Hazard and Risk Assessment: Methods and Models

Probabilistic quantification of tsunami current hazard using statistical emulation.

In this paper, statistical emulation is shown to be an essential tool for the end-to-end physical and numerical modelling of local tsunami impact, i.e. from the earthquake source to tsunami velocities and heights. In order to surmount the prohibitive computational cost of running a large number of simulations, the emulator, constructed using 300 training simulations from a validated tsunami code, yields 1 million predictions. This constitutes a record for any realistic tsunami code to date, and is a leap in tsunami science since high risk but low probability hazard thresholds can be quantified. For illustrating the efficacy of emulation, we map probabilistic representations of maximum tsunami velocities and heights at around 200 locations about Karachi port. The 1 million predictions comprehensively sweep through a range of possible future tsunamis originating from the Makran Subduction Zone (MSZ). We rigorously model each step in the tsunami life cycle: first use of the three-dimensional subduction geometry Slab2 in MSZ, most refined fault segmentation in MSZ, first sediment enhancements of seabed deformation (up to 60% locally) and bespoke unstructured meshing algorithm. Owing to the synthesis of emulation and meticulous numerical modelling, we also discover substantial local variations of currents and heights.

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.

Giant palaeotsunami in Kiribati: Converging evidence from geology and oral history

AbstractFor tsunami science within Oceania, the vast Central and Western Pacific (CEWEP) is an anomalous region because of the scarcity of historical tsunami observations and the complete absence of dated palaeotsunami evidence. This paper therefore records the first dated high‐magnitude palaeotsunami event within the CEWEP region. A combination of both geological data and oral history is provided for a palaeotsunami that struck remote Makin island, northernmost of the Gilbert Islands in Kiribati, toward the end of the 16th century. A previously undocumented oral tradition of giant waves is well known to the people of Makin. Narration of this legend by the Wiin te Maneaba, traditional storyteller on Makin, provided important details supporting a tsunami hypothesis. The legend preserves credible information surrounding the giant‐wave origin of Rebua and Tokia, two prominent subaerial megaclasts of blade and block geometry that were transported 80–130 m shorewards from the reef‐edge source and deposited in sideways and inverted orientations. From available hydrodynamic flow transport equations, minimum flow velocities of 7.3–16.3 m s−1 were generated, depending on whether the reefblocks were rotated or lifted onto the reef platform. The youngest U‐Th age‐dates for fossil corals retrieved from the reefblocks give a maximum age for the palaeotsunami of circa AD 1576. Several far‐field Pacific Rim and regional possibilities exist for tsunamigenesis. These include subduction‐zone seismicity and catastrophic volcanic eruption, both of which have been linked to earlier (late 15th century) palaeotsunami events recorded elsewhere in the Pacific Islands. However, the available evidence here suggests that the ~AD 1576 Makin palaeotsunami was more likely to have been locally generated by tsunamigenic offshore submarine slope failure close to Makin's western reef, associated with the giant arcuate bight structure that characterizes the northern rim of Butaritari atoll.

Assessment Of Tsunami Hazard In Sabah – Level Of Threat, Constraints And Future Work

The coastal areas of Sabah are exposed to far-field earthquake-induced tsunamis that could be generated along the trenches of Manila, Negros, Sulu, Cotabato, Sangihe and North Sulawesi. Tsunami simulation models from these trenches indicated that tsunami waves can reach the coast of Sabah between 40 and 120 minutes with tsunami wave heights reaching up to 3 m near the coast. The level of tsunami threat is high in southeast Sabah due to its narrow continental shelf and proximity to tsunami source in the North Sulawesi Trench. The level of tsunami threat is moderate in north and east Sabah due to their proximity to tsunami source in the Sulu Trench. The level of tsunami threat is low in west Sabah due to its distant location to tsunami source from the Manila Trench. While tsunamis cannot be prevented, its impact on human life and property can be reduced through proper assessment of its threat using tsunami simulation models. Unfortunately, constraints remain in producing a reliable tsunami inundation models due to the lack of high-resolution topography and bathymetry data in Sabah and surrounding seas. It would be helpful if such data can be acquired by the relevant government agencies, at least first, in high threat-level areas, such as Tawau and Semporna districts. In order to properly plan mitigation measures tsunami risk mapping should be intensified in high threat-level areas. The locations of settlements (including water villages), population concentrations, types of buildings and houses, road system, drainage system, harbours, jetties and vegetations (including mangroves) need to be mapped in great detail. Based on the detailed tsunami risk map, targeted vulnerable communities could be given continuous and intensive education and awareness on basic tsunami science and tsunami hazard preparedness.

Contributions of Space Missions to Better Tsunami Science: Observations, Models and Warnings

Most tsunamis occur after large submarine earthquakes, particularly in the Pacific Ocean. However, following the 2004 tsunami in the Indian Ocean, tsunami hazard awareness was significantly raised at the global scale, and warning systems were developed in many other regions, where large tsunamis are rarer but can also produce large catastrophes. Here we first review the basic physics of a tsunami, from its triggering to its coastal impact, and we offer a review of the geophysical and sea-level data that can describe the various processes operating during a tsunami. Global Navigation Satellite System (GNSS) data have a key role in better describing the ground deformation following a tsunamigenic earthquake close to the coast. The GNSS observations complement seismological data to constrain the rupture model rapidly and robustly. Interferometric Synthetic Aperture Radar (SAR) also contributes to this field, as well as optical imagery, relevant to monitoring elevation changes following subaerial landslides. The observation of the sea-level variations, in the near field and during the propagation across the ocean, can also increasingly benefit from GNSS data (from GNSS buoys) and from robust satellite communication: pressure gauges anchored on the seafloor in the deep ocean contribute to warning systems only by data continuously transmitted through satellites. The sounding of ionospheric Total Electron Content (TEC) variations through GNSS, altimetry, or a ground-based airglow camera, is a promising way to record tsunami initiation and propagation indirectly. Finally, GNSS, optical and SAR imagery are essential to map and quantify the damage following tsunami flooding. Satellite data are expected to contribute more to operational systems in the future provided they are reliably available and analysed in real time.

Introduction to “Twenty Five Years of Modern Tsunami Science Following the 1992 Nicaragua and Flores Island Tsunamis, Volume I”

Following the first volume (PAGEOPH, 2019, 176, No. 7), twenty-four papers on tsunamis are included in the PAGEOPH topical issue “Twenty five years of modern tsunami science following the 1992 Nicaragua and Flores Island tsunamis: Volume II,” reporting on the frontiers of tsunami science and research. The first two papers overview meteorological tsunamis, discussing progress since the 1992 Daytona event, and examining the March 2017 Persian Gulf destructive event. The next four papers review historical tsunami events, starting with a paper providing statistics for the last 120 years. The 2018 Kodiak event is investigated in the following two papers. A set of five papers discusses tsunami-warning methodologies specifically for the Australia and Nankai (Japan) regions, and general tsunami warning approaches. Probabilistic tsunami hazard assessment including case studies for two Australian coasts and the Pacific Coast of Central America, as well as discussion regarding the effect of shallow slip amplification uncertainty, and tsunami hazard assessment for the Port of Ensenada, Baja California, are presented in the next five papers. Two papers discuss tsunami tide interaction, and the following two investigate landslide-generated tsunamis, specifically a tsunami landslide scenario study for the Maltese Islands, and the 1694 Ambon, Indonesia tsunami. Tsunami hydrodynamics studies investigating shoaling on steep continental slopes and transmission of long surface, and tsunami-like waves are presented in the last two papers.

Ocean Observations Required to Minimize Uncertainty in Global Tsunami Forecasts, Warnings, and Emergency Response

It is possible that no catastrophe has mobilized the global ocean science and coastal emergency management communities more than the 2004 Indian Ocean tsunami. Though the Pacific tsunami threat was recognized, and a warning system had been in place since 1965, there was no warning system in the Indian Ocean, and almost 230,000 people perished. More broadly, the event highlighted critical gaps in global tsunami science and observation systems. In 2004, real-time coastal and deep-ocean observation systems were almost nonexistent. Tsunami sources were inferred based on rough seismic parameters. Since then, tremendous strides have been made under the auspices of IOC/UNESCO toward better understanding tsunami mechanisms, deploying advanced real-time tsunami observation systems, and establishing tsunami warning and mitigation systems for the four main ocean basins at risk from tsunamis. Nevertheless, significant detection, measurement, and forecast uncertainties remain to meet emergency response and community needs. A new generation of ocean sensing capabilities presents an opportunity to address several of these uncertainties. Ocean bottom pressures can be measured over dense, multisensor grids linking stand-alone buoy systems with emerging capabilities like fiber-optic cables. The increasing number of coastal sea-level stations can better verify forecasts and account for local variability. In addition, GNSS sensors may be able to provide solid-earth data needed to define seismic tsunami sources more precisely in the short timescales required. When combined with advances in seismology, other emerging techniques, and state-of-the-art modeling and computational resources, these capabilities will enable more timely and accurate tsunami detection and measurement to meet identified user needs and save lives. Because of these advances in detection and measurement, the opportunity exists to greatly reduce and/or quantify uncertainties associated with forecasting tsunamis. Providing more timely and accurate information related to tsunami location, arrival time, height, inundation, and duration would improve public trust and confidence and fundamentally alter tsunami emergency response. Additionally, this capability could be integrated with related fields (e.g., storm surge, sea-level rise, tide predictions, and ocean forecasting) to develop and deploy one continuous, real-time, accurate depiction of the always moving boundary that separates ocean from coast, wet from dry, and, sometimes, life from death.

Twenty-Five Years of Progress in the Science of “Geological” Tsunamis Following the 1992 Nicaragua and Flores Events

We review a set of 47 tsunamis of geological origin (triggered by earthquakes, landslides or volcanoes) which have occurred over the past 25 years and provided significant new insight into theoretical, experimental, field, or societal aspects of tsunami science. Among the principal developments in our command of various aspects of tsunamis, we earmark the development of the W-phase inversion for the low-frequency moment tensor of the parent earthquake; the abandonment of the concept of a maximum earthquake magnitude for a given subduction zone, controlled by simple plate properties; the development and implementation of computer codes simulating the interaction of tsunamis with initially dry land at beaches, thus introducing a quantitative component to realistic tsunami warning procedures; and the recent in situ investigation of current velocities, in addition to the field of surface displacements, during the interaction of tsunamis with harbors. Continued research remains warranted, notably in the field of the real time identification of “tsunami earthquakes” whose tsunamis are larger than expected from their seismic magnitudes, especially conventional ones. The recent tragedy during the 2018 Krakatau flank collapse, along a scenario which had been quantitatively forecast, also emphasizes the need for a continued effort in the education of the populations at risk.

Introduction to “Global Tsunami Science: Past and Future, Volume III”

Introduction to “Global Tsunami Science: Past and Future, Volume III”

About this title ‐ Tsunamis: Geology, Hazards and Risks

This Special Publication examines tsunami hazard and risk, with particular focus on using the geological record. With Earth's growing population clustered increasingly on coastlines, tsunami hazards are of concern worldwide. The papers explore the sedimentological and dynamic traces of recent and prehistoric tsunamis globally – from Europe to the Pacific – as well as looking at historic records and how the information can be used to characterise the scale of impacts and areas that are most susceptible to tsunami hazards. Armed with this information, scientists can begin to quantify risks, both to populations and in economic terms. This volume is aimed both at scientists working in this field and at a wider community, interested in tsunami science and natural hazard assessment.

Preserving past tsunami information for future preparedness in Indonesia and the Philippines

Recent tsunamis, especially after the 2004 Indian Ocean tsunami, provided a better understanding and knowledge of tsunami science as well as on how to build awareness and preparedness. However, tsunamis that happened before 2004, there is limited and/or scattered data, information, records, and reports of the events. In addition, there is either limited or no eyewitness’s story documented, including pictures and videos. The lack of information makes it difficult for policymakers, researchers, and other institutions to disseminate local and contextualized information to the public in raising awareness and education on disaster preparation and mitigation. If a tsunami has happened in the past, it is most likely to happen again in the future. It is imperative that we learn from the past and prepare for the future. This study aims to improve the knowledge of the impact of the tsunami in selected sites in Indonesia and the Philippines prior to 2004, through investigation of historical documents and archives, as well as documentation of eyewitness accounts. The result of this study is expected to be a more effective way to build awareness and to educate the local community. Having evidence-based of past tsunami event in the area will motivate stronger preparedness. It will also provide a better understanding to the local policymakers, disaster management agencies, as well as the community as it is based on local eyewitness accounts and other local sources, as opposed to using examples from other sites, districts, countries or regions.

Complete Implementation of the Green's Function Based Time Reverse Imaging and Sensitivity Analysis of Reversed Time Tsunami Source Inversion

AbstractIn recent studies, the Time Reverse Imaging (TRI) method has been implemented in tsunami science to estimate tsunami source models. A TRI algorithm called Green's Function Based Time Reverse Imaging (GFTRI) was previously developed to reconstruct the source model by using source inversion as a guide to appropriately scale time‐reversed images of the tsunami source. In this article, we consider a more complete approach to source inversion using reversed time images of the tsunami source by considering cross correlations among Green's functions. As a consequence, the performance of the method improves significantly. We tested this new algorithm using data from the 2011 Japan tsunami. Our results show that the method is capable of extracting more details of the source and providing excellent waveform fits at all stations, including those not used in the source imaging. We have also studied the sensitivity analysis of reversed time tsunami source inversion and found that the method is less sensitive to the number of stations, once a minimum number of stations is utilized. Moreover, this new approach is able to estimate the tsunami source with reasonable accuracy using data available soon after an earthquake, which indicates that it has potential to be used in both near‐ and far‐field tsunami forecasting.

Introduction to “Global Tsunami Science: Past and Future, Volume II”

Twenty-five papers on the study of tsunamis are included in Volume I of the PAGEOPH topical issue ‘‘Global Tsunami Science: Past and Future’’. Six papers examine various aspects of tsunami probability and uncertainty analysis related to hazard assessment. Three papers relate to deterministic hazard and risk assessment. Five more papers present new methods for tsunami warning and detection. Six papers describe new methods for modeling tsunami hydrodynamics. Two papers investigate tsunamis generated by non-seismic sources: landslides and meteorological disturbances. The final three papers describe important case studies of recent and historical events. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.