Tsunami Risk Research Articles

Mapping Of Tsunami Risk Zones On Lombok Island To Support Military Operations Other Than War (OMSP)

Mapping Of Tsunami Risk Zones On Lombok Island To Support Military Operations Other Than War (OMSP)

Are Indian ports safe? Identifying, analysing and prioritizing the risks affecting India's major ports

Seaports are exposed to multiple risks that may affect security and operations. This research aims to develop a framework for identifying, ranking, and prioritizing the risks. Also, this study ranks the 12 major Indian ports based on the identified risk factors. The study follows an extensive literature review, prioritization by Fuzzy TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), and sensitivity analysis for robustness. Thirty-two risks were identified and classified into five categories: natural disasters, geographical risks, security risks, operational and financial risks, and socio-political risks. The analysis suggests that the most important risk that the ports in India should consider is natural disasters. The risk of cyclones and tsunamis occupied the first two ranks among the global risks. Operational and financial risks, such as complex and lengthy approval procedures and infrastructure risks, are ranked third and fourth. Mumbai is ranked first as the riskiest Indian port, followed by Kolkata, JNPT (Jawaharlal Nehru Port Trust), and Vishakapatnam Port

Tsunami Vulnerability Analysis Based on Coastal Typology in the Coastal Area of Ende City

A tsunami disaster threatens Ende City. Ende City's coastal area management policy regarding disaster mitigation must consider coastal typology. Efforts to reduce the risk of tsunamis must pay attention to the physical development of coastal land to maintain the coastal resources. Therefore, this research aimed to analyze the level of tsunami susceptibility based on coastal typology in the coastal area of Ende City. The methods used in this research are survey and spatial analysis. The survey results were compared with literature studies to determine coastal typology and land use. Spatial analysis uses overlay, scoring, and weighting techniques to produce tsunami susceptibility levels. Geospatial parameters that determine the level of susceptibility are topography, distance from the coastline, slope, distance from rivers, and coastal morphology. Susceptibility analysis is carried out for each coastal typology because each has a different response to tsunami. The research results show five classes of tsunami susceptibility: very susceptibility, susceptibility, somewhat susceptibility, safe, and very safe. Very susceptible areas are marine deposition coast typology, anthropogenic coast typology, and sub-area deposition coast typology. The secure areas are wave erosion coast typology and volcanic coast typology.Keywords: Coastal City of Ende, Coastal Typology, Tsunami, Susceptibility, Land Use.

When the Past Teaches the Future: Earthquake and Tsunami Risk Reduction through Episodes of Situated Learning (ESL)

The past offers important lessons with regard to facing the future with greater awareness. In this context, school plays a key role in spreading knowledge of natural phenomena and in promoting behavior change. Together with researchers, teachers can be strong allies to build more resilient future citizens. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) school training activities provide tools to prepare for the next earthquake and/or tsunami. Approximately 5000 students, from both middle schools (ISCED 2) and high schools (ISCED 3), were involved in active learning activities based on a flipped-up approach during specific online scientific events during the pandemic. Online lab activities were conducted during European Researchers’ Night (“Earthquakes: history teaches us the future: researchers for a day with experimentation in didactics for ESL”) and during both World Water Day 2021 and World Earth Day 2021 (“Tsunamis: history teaches us the future researchers for a day with experimentation in didactics for ESL”). These two Episodes of Situated Learning (ESL) experiences triggered students’ interest, favoring remote learning, developing life skills, and focusing on historical seismic studies of both past earthquakes and tsunamis.

Tsunami deposits in Tunisia contemporaneous of the large 365 CE Crete earthquake and Mediterranean Sea catastrophic event

New field investigations along the East Tunisian coastline reveal sedimentary deposits and damaged localities that may account for a catastrophic event during the late Holocene. North of Sfax city, ~ 3.4 m high cliff coastal marine and alluvial terraces show 20 to 50-cm-thick chaotic layer with sandy coarse gravels mixed with reworked pebbles, broken shells of gastropods and molluscs, organic matter and Roman pottery. The chaotic layer truncates sandy-silty paleosol, covers Roman settlements and is overlain by fire remains, a thin sandy-silty aeolian unit and ~ 1-m-thick alluvial deposits. Charcoal samples collected at 10 cm below and 4 cm above the catastrophic deposits provide radiocarbon dating that brackets the catastrophic unit between 286 and 370 CE. Other historical investigations on the Roman sites of Neapolis (Nabeul), Hadrumete (Sousse), Thyna (Sfax), Meninx in Girba (Djerba), Wadi Ennouili (Gulf of Gabes), and Sabratha (in Libya) evidenced major damage and abandonment of sites in the fourth century (16, 41, 42, 43, 44). The new identification of catastrophic deposits, offshore-onshore correlations with turbidites and modelling of tsunami waves suggest the relationship with the 21 July 365 tsunamigenic earthquake (Mw ~ 8) of west Crete (Greece) and call for a better estimate of tsunami risk on the Mediterranean coastlines.

Disaster cultures and the Indonesia Tsunami Early Warning System: (mis)alignments revealed by the 2018 non-tectonic tsunami in Labuan

This study examined the (mis)alignments between multiple disaster cultures, the Indonesia Tsunami Early Warning System (InaTEWS) and local risk profiles as revealed by the 2018 non-tectonic tsunami triggered by the Anak Krakatau Volcanic eruption in Labuan. The research assessed to what extent the tsunami warning system was adapted to local needs and characteristics. Based on qualitative data collection, this study showed that before the 2018 tsunami (and notwithstanding memories of the 1883 Krakatau tsunami) different local groups shared a strikingly homogeneous understanding of tsunamis as exclusively triggered by earthquakes. After the 2018 tsunami, study participants reported increased awareness of different tsunami types and earthquake risks. However, this rarely translated into practical actions and changes at the local level as structural and cultural factors significantly hampered the work of local government and emergency management agencies. This research identified steps to improve alignment, for example by involving community members in warning technology maintenance, tailoring awareness-raising materials to local hazard profiles and connecting awareness-raising with local cultural traditions. However, a reform of the InaTEWS is necessary, including overcoming sectoral silos and incorporating local knowledge and experiences into policymaking. By addressing these (mis)alignments, authorities can better support communities to understand tsunami risks and respond to future event, ultimately enhancing preparedness.

Assessing tsunami risk along the Aceh coast, Indonesia: a quantitative analysis of fault rupture potential and early warning system efficacy for predicting arrival time and flood extent

The Aceh coast (western Indonesia) is prone to regular tsunamis, as evidenced by historical records and paleo-tsunami studies. Effective community preparedness and response plans are essential in this context. Critical to these efforts is understanding the Estimated Times of Arrival (ETAs) of tsunamis, which dictate the vital window for post-earthquake actions and the likelihood of survival during an approaching tsunami. Our study aimed to assess the time available for communities in Aceh and nearby islands (Weh, Nasi, Breuh, Simeulue, Banyak) to respond and evacuate following an earthquake. We investigated ETA influenced by faults like Aceh-Andaman, Nias-Simeulue, and Batu segments, considering earthquake scenarios: 9.15 Mw (2004 tsunami reconstruction), 9.2 Mw, 8.9 Mw, and 8.6 Mw for Nias-Simeulue and Batu segments. Using the nonlinear shallow water equation (NSWE) model and numerical discretization with the finite difference method, we simulated tsunamis and projected arrival times. Our findings highlighted critical ETA ranges: 8–25 min on northern coasts, 19–37 min on western shores, 17–27 min on southwestern coasts, and 11–67 min on southern coasts. These results are essential for enhancing early warning systems and optimizing evacuation plans, and bolstering coastal community preparedness and resilience to tsunamis. Further studies are needed to conduct a comprehensive investigation of ETA, which includes potential rupture scenarios and a wider observation area, including expanding the modeling of tsunami generation mechanisms, which includes tsunamis generated by underwater landslides due to earthquakes or volcanic activity. Assessing ETA is pivotal for tsunami preparedness, contributing to more effective early warning systems and evacuation strategies. Integrating our ETA findings into policies will significantly enhance the preparedness and resilience of coastal communities in the face of ongoing tsunami risks. This study represents a valuable contribution to disaster risk reduction, offering actionable insights for safeguarding vulnerable coastal regions.

A Review of Structural Vulnerability Assessment Methods in the Advent of a Tsunami

The interaction between hazard and exposure gives rise to risk. Tsunami risk assessment is derived from both hazard assessment and vulnerability assessment. Exposure can manifest in various aspects, such as social factors (e.g., population), environmental factors (e.g., agricultural areas), or economic factors (e.g., infrastructure). Our focus in this review paper is specifically on economic exposure, with an emphasis on structural vulnerability assessment. The approaches employed in tsunami vulnerability assessment are diverse. In this paper, we categorize them into simplified and in-depth methods, encompassing: (1) Empirical vulnerability functions, (2) Index-based approach, (3) Building tsunami vulnerability model (BTV).

The Tsunami Generated by the Gorringe Bank Fault: Analyzing Wave Heights and Travel Time in the Atlantic Coast of Morocco

Two hundred sixty-eight years (about three centuries) since the 1755 Lisbon tsunami, which provoked large-scale damage in Portugal, Spain and Morocco. Scientists in several countries have mobilized to develop investigative methods to study this extraordinary tsunami, with the aim of reducing the impact of waves in future events and protecting and warning populations at risk. However, the most important question remains whether the entire damaged community has sufficient information about the impact to prepare for tsunami risks. The aim of this paper is to determine the maximum wave heights in selected cities located within high-risk tsunami zones in Morocco, as well as the tsunami arrival time for each site. We used the Non-linear Shallow Water model With Nested Grids (NSWING) code to model tsunami propagation. Six cities were determined as observation points as being the subject of tsunami studies in previous work, namely Tangier, Asilah, Rabat, Casablanca, El-Jadida and Safi. The maximum wave height calculated within the Atlantic coast of Morocco exceeds 5 m in some locations and the first waves reach the Moroccan coast in 60 minutes. The authorities might utilize these results to develop evacuation plans.

Staff Perceptions of Tsunami Risk on the Fukushima Coast and Their Difference within the Tokyo Electric Power Company Before the Fukushima Accident

Staff Perceptions of Tsunami Risk on the Fukushima Coast and Their Difference within the Tokyo Electric Power Company Before the Fukushima Accident

Reconstruction of the Indian Ocean Tsunami in 2004 in Sabang Based on the Current Land Cover for Tsunami Evacuation Sites Recommendations

Sabang City has grown in term of city’s population as well as the tourism activity. The development also meant there are more area that has been used when compared to the time before the 2004 tsunami. This research was developed to re-identify tsunami-prone zones with the current land cover condition in Sabang City and to provide recommended safe locations, alternative evacuation routes, and additional evacuation sites. We used Cornell Multi-grid Coupled Tsunami Model (COMCOT) to carried out the tsunami simulation added with updated land cover to provide more accurate simulation model. The simulation pointed out several tsunami hazard zones in Sabang City, such as Balohan, Kuta Ateuh, and Iboih with expected tsunami heights to be more than 3 meters and arrival time less than 60 minutes. Those areas then surveyed to develop recommendations for tsunami risk reductions. The recommendations included nine additional evacuation buildings are proposed, three sites in each zone. Another recommendation is in form of evacuation routes in each zone to complement existing routes stated in RTRW document.

A review of tsunami early warning at the local level - Key actors, dissemination pathways, and remaining challenges

At the International Symposium on the Lessons Learnt from the 2018 Tsunamis in Palu and Sunda Strait, organised by IOC-UNESCO, experts identified the need for a critical dialogue on the future direction of tsunami warning systems, especially for events other than tectonic origins and with short warning times. This first phase of a longer-term study was initiated to develop a better understanding of tsunami early warning at the local level in countries exposed to a tsunami risk. This desk study involved a systematic literature review of academic publications from 2005 to 2021, and a narrative literature review to examine policy and guidance reports on tsunami early warning. Seven guiding research questions were identified to set the boundaries of the research and provide a clear framework for the review. The draft questions were reviewed and, through several iterations, refined by academics and representatives of working groups and technical agencies involved in tsunami early warning. The findings reveal the characteristics of the literature on tsunami early warning at the local level, as well as insights into how early warning approaches vary across Ocean Basins and between countries. The results revealed substantial challenges that hinder effective tsunami early warning at the local level, such as inadequate coordination of actors. Among several areas for improvement, the need to promote a culture for self-evacuation has been identified as a practical solution to face nearfield tsunamis. The results of this analysis will inform further detailed empirical investigations to provide contemporary insights on the status of tsunami early warning at the local level in different countries.

Involvement and Design of Strengthening Policy Actors in Tsunami Disaster Risk Governance in Padang City

This paper is based on research that describes the involvement and design of strengthening policy actors in tsunami risk governance in Padang City. This paper also describes the policy design for strengthening disaster risk governance based on these actors' participation in research findings. The approach used in this research is a qualitative method with data collection through in-depth interviews, focus group discussions, and data studies. Data processing and analysis were performed using matrix coding and model design on the NVivo 12 Plus. The research findings illustrate that the involvement of local government actors is at the highest level in disaster risk governance policies in Padang City. Furthermore, non-governmental organisations, communities, vertical governments, digital communities, and business sector actors have successive roles in disaster risk policies. Recommendations for the involvement of local communities can be made by increasing capacity and engaging in disaster risk governance actions. On the other hand, the recommendation of non-governmental organisations (NGOs') participation should be maintained and facilitated by designing regulations that reduce the risk of a tsunami disaster. Local governments are involved in strengthening budgeting, coordination, and partnerships as the leading sector in disaster governance.

Analysis of the Relationship Between Shallow Water, Flood, and Tsunami

Contemporarily, it is necessary to delve into the intricate connections between shallow water dynamics, flood events, and tsunamis, elucidating their pivotal role in disaster management and environmental studies. This study explores how shallow water conditions influence the behavior of floods and tsunamis through recent advancements, numerical modeling, and observational techniques. The framework of the study involves an examination of the fundamental concept of shallow water, its characteristics, and its influence on wave behavior, sediment transport, and coastal interactions. The study subsequently analyzes the interplay between shallow water and floods, emphasizing the rapid increase in water levels as floodwaters approach shallower areas, contributing to coastal inundation. Similarly, the investigation explores how shallow water dynamics amplify tsunami wave heights and impact, particularly in coastal settings with complex features. By employing advanced simulations and real-world data, the study substantiates the crucial role of shallow water in shaping flood and tsunami risks. While acknowledging limitations, the research concludes by underscoring the implications of these relationships for disaster preparedness, environmental protection, and community resilience. The study contributes to a comprehensive understanding of the profound effects of shallow water dynamics on catastrophic events and highlights the importance of factoring these dynamics into effective disaster management strategies.

Integrated tsunami risk framework considering agent-based evacuation modelling: The case of Saga, Kochi Prefecture, Japan

This study develops an integrated tsunami risk framework combining stochastic tsunami hazard and agent-based evacuation modelling. The framework is applied to the case of Saga, Kochi, Japan, with a population of ∼ 2,200 anticipated to experience significant tsunami events (∼ M9.0). First, stochastic earthquake source models are generated for two values of magnitudes (M8.8 and M9.0) and used to carry out stochastic tsunami inundation simulations. Agent-based tsunami evacuation modelling using MATSim is then performed by considering four mode scenarios: single mode (pedestrian and car) and two multimodal scenarios (mix of car and pedestrian). The stochastic tsunami simulations and agent-based evacuation modelling results are integrated to estimate the risk. The effect of existing tsunami evacuation points and tsunami evacuation towers on risk reduction is also assessed. Such an integration framework is finally used to recommend tsunami mitigation strategies in the tsunami-prone regions. Results show that a significant tsunami hazard (i.e., tsunami depth up to 15 m) is expected in the Saga district, with an arrival time between 5 and 30 min. In addition, the evacuation points on higher grounds effectively save local residents' lives, as shown by the small number of affected people, specifically for the pedestrian and multimodal models (i.e. 10-100 people, excluding the car model). However, up to ∼ 1,000 people may get affected if car is the sole mode of evacuation. Therefore, the coastal community is recommended to evacuate on foot. Finally, identifying and securing sufficient higher grounds and vertical evacuation points are essential for risk reduction.

Strengthening tsunami maritime response and mitigation through inclusive stakeholder engagement: Lessons learned in Washington State

Among the most vulnerable facilities to tsunami impacts are ports, harbours and marinas. The ability of maritime infrastructure to withstand a disaster and resume operations quickly plays a major factor in the recovery of the local community and economy in the short and long term. Despite this, little established guidance exists to assist the maritime community with addressing their tsunami risk in an actionable, site-specific manner. To close this gap and improve the resilience of its maritime community, Washington State has begun developing tsunami maritime response and mitigation strategies for major ports, harbours and marinas along its 3,200 miles of coastline. These strategies include detailed information about the location’s specific tsunami risk, recommended guidance for vessel operators in the area, and tsunami mitigation and response recommendations ranked by their implementation feasibility for the maritime entity in question. Most importantly, the strategies are created through close collaboration with local key stakeholders, subject matter experts, local emergency management and state agencies to ensure a final deliverable that is accurate, thorough and, above all, useful to the local maritime entity and its tenants and users. As this paper will discuss, the lessons learned during the planning and delivery of these strategies provide valuable insight for professionals in the maritime, business continuity and emergency management fields, including how to conduct effective and inclusive stakeholder engagement, identify gaps and opportunities in resilience planning, and establish a deeper understanding of tsunami maritime risk and hazards.

Boulder transport and wave height of a seventeenth-century South China Sea tsunami on Penghu Islands, Taiwan

Abstract. The South China Sea faces widespread tsunami risks from diverse sources, including trench megathrusts, intraplate earthquakes, and landslides. However, historical and geological records to constrain worse-case simulations are scarce. The cliff-top basalt boulders on the Penghu Islands in the Taiwan Strait provide wave estimates from incipient motion formulas and stratigraphic links to the probable sources. Calibrating for ancient local sea levels and a 100-year surge indicates that storm waves in the shallow interisland bathymetry only enable boulder sliding–rolling below the 2.5 m high cliff. A minimum tsunami wave height of ∼ 3.2 m is necessary for cliff-top overflow to exceed boulder height and terminal rolling before deposition. Coeval gravels in two other outcrops also record the time and extent of tsunami deposition with beach-derived bioclasts, stranded pumices, a sharp base, matrix support, poor sorting, and elevations surpassing the 100-year surge. These gravels mark local minimum wave run-ups, reaching 2.4–4.0 m above sea level. The radiocarbon age of the studied boulder, between 1575 and 1706, suggests a probable tie to the disastrous 1661 earthquake in southwest Taiwan and the megathrust source in the northern Manila Trench.

Three-dimensional numerical investigation of floating debris effects on bridge superstructures during tsunamis

Catastrophic tsunamis occur around the world and as coastal communities continue to grow, consideration of cascading tsunami-borne debris effects on coastal structures becomes increasingly important. The objective of the present study is to address the gap in existing knowledge by advancing the fundamental understanding of the debris-tsunami-structure interaction of floating containers and quantifying the forces on representative bridge superstructures. To this end, a coupled SPH-FE modeling approach is calibrated against data from prior experiments and then used for conducting an extensive three-dimensional investigation. The results demonstrate that the initial water level, the elevation of the bridge and the bore properties have a significant effect on the debris trajectory, velocity and pitching, as well as, the forces on the superstructure. Moreover, there exist three different patterns in the debris-flow-deck interaction of containers aligned transverse to the flow (i.e. parallel to the bridge), which affect the direction of debris forces and their spatial and temporal evolution. Overall, the debris generates impulsive forces in both horizontal and vertical directions and consequently increase the total loads by a factor of 2.67 and 1.85, on average in the two directions, revealing the critical need to consider such effects in tsunami design guidelines and risk assessment frameworks.

Understanding memory transmission in disaster risk reduction practices: A case study from Japan

“Disasters strike when they have faded from memory”, is a powerful quote from the Japanese geophysicist Terada Torahiko (1878–1935). This sentence, often used when addressing the need to improve disaster resilience, is a powerful reminder of the role that local memories of past disasters play in ensuring the safety of communities exposed to hazards. Twelve years from the Great East Japan Earthquake and Tsunami (GEJET) that hit Japan Tohoku's East Coast, this article aims at understanding how the transmission of local knowledge and experiences of past disasters contributes to increasing community resilience to tsunami risks. Based on field research along the coast of the Japanese prefectures of Iwate, Miyagi and Fukushima, this study analyses 11 semi-structured in-depth interviews, to investigate the role of memory transmission in preparing for tsunami risks such as the GEJET. The data was analysed following a narrative approach and through thematic coding with the use of NVivo. Coding structures led to the identification of disaster memory transmission practices in the case study areas and allowed the testing of the relevance of the theoretical framework to community disaster resilience studies. Results are aligned with the theoretical framework and show that disaster memorials are more likely to influence community resilience if passed down using a combination of oral transmission and interpretation together with the use of backup memory archives and physical objects. Such practices are recommended as they allow both the communicability and durability of lessons-learned. Transmitting and maintaining a constant interaction between these two forms of memory is the responsibility of those institutions that oversee the keeping alive of memories, by continuously repurposing and renewing them while engaging with exposed communities.

Utilization of QGIS 3.22 with a Spatial Approach in Assessing Tsunami Risk on Small Islands in Ternate City

Utilization of QGIS 3.22 with a Spatial Approach in Assessing Tsunami Risk on Small Islands in Ternate City