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The article discusses the use of magnetometric remote sensing to study large-scale electric currents induced by ocean flow sources, focusing on physical oceanography, natural hazards, and planetary studies. In physical oceanography, studies have successfully extracted tidal magnetic fields from satellite data to monitor ocean heat uptake due to climate change. Natural hazards research explores tsunamigenic magnetic fields for tsunami warning systems. Planetary studies aim to detect subsurface oceans in satellites of Uranus and Neptune using electromagnetic signals. The article provides insights into the applications and advancements in magnetometric remote sensing of Earth and planetary oceans. [Extracted from the article]

Electrically conductive seawater, moving in an ambient magnetic field, generates electromagnetic (EM) variations. Tsunamis are significant contributors to this phenomenon, inducing observable electric and magnetic fluctuations at seafloor and coastal observatories. While understanding of these occurrences in open oceans is robust, knowledge regarding their observation on islands remains limited. This article seeks, through the use of numerical experimentation, to enhance our understanding of tsunami-generated EM (TGEM) variations observed on islands. Utilizing simulations involving conical islands, we identify three key insights regarding EM intensity normalized by the height of incident tsunamis: (i) increased ocean depth surrounding the island amplifies tsunami EM signals, particularly for periods shorter than 20 min; (ii) magnetic field strength at the island is approximately comparable to that observed at the seafloor in the absence of the island when the island radius is smaller than 6 km; and (iii) electric field intensity at the island notably surpasses that observed at the seafloor, especially with smaller island radii (≤ 6 km). Additionally, we establish that employing the ratio of island radius to tsunami wavelength near the island coast facilitates the derivation of empirical functions for this phenomenon. This article is part of the theme issue 'Magnetometric remote sensing of Earth and planetary oceans'. [ABSTRACT FROM AUTHOR]

The relationship between forest damage by tsunamis and crown base height has rarely been examined mechanistically. Since tsunami hazard mitigation effects are reduced in areas near destroyed coastal forests, this phenomenon must be examined in detail. Accordingly, we examined the influence of crown base height and inundation depth on tsunami damage using a mechanistic model, and two models based on the generalized allometric equation and statistical methods were developed to estimate the mean crown base height of coastal Japanese black pine (Pinus thunbergii Parlat.) forests. The mechanistic model showed that the moment causing trunk breakage or overturning increased drastically when inundation depth exceeded the crown base height. This drastic increase in moment increases the risk of tsunami damage in coastal forests. Dataset 1 for 54 stands located in Hokkaido, northern Japan, was investigated to construct two models estimating mean crown base height, which were validated with data on 43 stands (dataset 2) based on previous studies in Honshu. The RMSE between the estimated and observed mean crown base height was 0.42, 0.71, and 0.57 m for dataset 1, dataset 2, and dataset 1 + 2, respectively, in the generalized allometric equation model. The RMSE values in the statistical model were 0.40, 0.62, and 0.51 m for dataset 1, dataset 2, and dataset 1 + 2, respectively. The two models in this study can thus estimate the mean crown base height in areas other than Hokkaido and allow us to estimate crown mean base height and control it through proper thinning. [ABSTRACT FROM AUTHOR]

Coastal areas around the South China Sea are threatened by potential tsunamis triggered by large earthquakes in the Manila Trench. To quantitively assess the inundation probability caused by tsunamis is crucial for coastal disaster prevention and mitigation. This study focuses on the eastern coast of Hainan Island, which is located to the west of the Manila Trench and may directly face tsunami impact. More than one million tsunami scenarios are simulated considering the randomness of earthquake magnitude, epicenter location, and focal depth. The simulation of numerous tsunami scenarios is based on the unit source superposition method in deep water, which provides boundary conditions for the local model with high spatial resolution for nearshore wave propagation and inundation. Representative waves with different heights and periods are adopted as incident waves in the local model. By involving the joint probability density of incident wave height and period, the spatial distribution of inundation probability is given along the eastern coast of Hainan Island. This study provided an assessment method for the inundation probability, which can more comprehensively consider the uncertainty of earthquakes and provide a more reliable assessment result than that based on refined simulation of several typical scenarios. [ABSTRACT FROM AUTHOR]

Experimental and numerical studies were conducted to assess the stability of the breakwater of Fujairah Port on the east coast of the United Arab Emirates against tsunamis. Experiments were conducted on a 1:50 scale and numerical analysis was done with the formulas of tsunami-breakwater interaction. The experimental observations corroborated the numerical results. The breakwater was safe up to 3 m of tsunami height, but when the tsunami height increased from 3 m to 6 m, the percentage damage to the leeside (portside) of the breakwater increased compared to the seaside. The leeside of the breakwater was deformed by tsunami overtopping and seepage — the breakwater cross-section reshaped from trapezoidal to quasi-triangular at 6 m tsunami impact, however, the breakwater was not breached. Rubbles of the breakwater were transported due to sliding, rolling, and saltation by overtopping and seepage. For 6 m tsunami height, rubbles from the seaside rolled over up with saltation and transported to the leeside. A large number of rubbles were transported landward from the leeside of the breakwater but a few were displaced offshore from the seaside. [ABSTRACT FROM AUTHOR]

Southwestern British Columbia in Canada has a high likelihood of facing significant earthquake threats in the future. It is exposed to significant seismic and tsunami hazards, originating from the Cascadia subduction zone and shallow crustal and deep inslab earthquakes. This study presents a new probabilistic earthquake-tsunami loss model for the Cascadia subduction zone by focusing on the District of Tofino, British Columbia. The earthquake occurrence and rupture models for the Cascadia subduction zone are developed by incorporating the time-dependency of earthquake occurrence and by adopting a stochastic source modelling approach, which allows for consideration of heterogeneous earthquake slip distributions. The results produce single-hazard and multi-hazard exceedance probability loss curves for earthquakes and tsunamis from the Cascadia subduction zone. In addition, earthquake risks due to other seismic sources are integrated with the multi-hazard loss curves due to the Cascadia events. In this way, a complete financial exposure from all major seismic and tsunami sources is evaluated. These loss curves can be used for determining the insurance rates for multi-hazard and multi-source risk coverage. The results are beneficial for providing more risk financing options via insurance against the future Cascadia and other seismic events. [ABSTRACT FROM AUTHOR]

As an important renewable engineering structure, offshore wind turbine foundation is threatened by tsunami bore. A three-dimensional numerical model of dam-break wave tsunami is established and validated based on computational fluid dynamics to study the impacting effects of gravity-based foundation (GBF) of offshore wind turbines under tsunamis. The impacting process of the small, middle, and large tsunami on the GBF is numerically simulated, and the load effects characteristics of the GBF of the wind turbine at different stages of the tsunami impact process are analyzed. The research results show that the GBF is subjected to two peak impact forces under tsunami-impacting action. The tsunami bore has a frontal impact on the GBF, and the force peak of the flow direction is the largest, which has the greatest impact on the foundation of the wind turbine. Specifically, the middle tsunami exerts a maximum frontal impact force of 16.8N, with a peak dynamic pressure of 678.2 Pa, and a maximum base moment of 1.24N⋅m. Besides, the variation on the base moment in the incident flow direction of the incoming is larger than that in the transverse direction. The research provides valuable insights into the tsunami-resistant GBF, offering recommendations and guidelines for ensuring the long-term stability of offshore wind turbines in tsunami-prone regions. [ABSTRACT FROM AUTHOR]

This study examines a significant accumulation of deposits on an abnormal slope in the southern Caspian Sea, which is believed to be a potential source of submarine landslides due to seismic activity in the faulting system of the northern Iranian plateau. A presumed earthquake Mw 7.7 originating from the Khazar Fault is identified as the triggering event for the landslide, and the induced landslide tsunami is simulated using the fully nonlinear and dispersive Boussinesq equations to assess the tsunami hazard along the southern coasts of the Caspian Sea. Considering the uncertainty in the dimensions of landslide, two scenarios are defined involving small and large submarine mass failures with volumes of 0.22 and 1.51 km3, respectively. The results indicate that the waves generated by the small landslide scenario reach approximately 1 m in height along the coastline, whereas waves as high as 8 m are observed during the large landslide tsunami. The tsunami waves diminish as they propagate along the coasts distant from the landslide location. However, in the case of a large probable landslide, the tsunami waves reach run-up heights of up to 4 m and inundate 300 m inland' min the target area of the study (Anzali Port). The significant disparity between the two simulated scenarios highlights the importance of accurately estimating the potential locations and volumes of landslides, as well as the necessity of conducting further geological surveys to comprehensively evaluate tsunami hazards. [ABSTRACT FROM AUTHOR]

Copyright of Gaceta Médica de Caracas is the property of Academia Nacional de Medicina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tsunamis, generated by submarine earthquakes, landslides, or volcanic eruptions, are a significant hazard to coastal areas owing to their sudden onset and rapid propagation speed. Thus, tsunami disaster risk assessment is crucial to determine potential losses and severity of future tsunami impacts, providing essential support for disaster prevention and mitigation efforts. This study presents a case study of Xiamen City in Fujian province for developing a high-precision tsunami model. Utilizing nearshore water depth and digital elevation model data, we established a high-resolution tsunami numerical simulation model for Xiamen City that accounts for the impact of water overrunning levees and overshoals. Historical tsunami disaster records were used to validate the numerical model. By determining multiple tsunami source scenarios that could potentially affect the counties of Xiamen City, we simulated the inundation range and water depth distribution required for the potential maximum tsunami event. The simulation results facilitated a tsunami hazard assessment. Considering land use and important tsunami-affected exposures including industrial and chemical enterprises and ports, we evaluated the vulnerability of Xiamen City to tsunami disasters. Based on the determination of hazard and vulnerability levels, we investigated the risk distribution of tsunami disasters in Xiamen City. The results of this study lay the groundwork for developing methodologies to improve tsunami disaster risk assessment in coastal areas. [ABSTRACT FROM AUTHOR]

On 8 October 2023 (UTC), unique earthquakes occurred in the Izu‐Ogasawara Arc, Japan, in which the P‐ and S‐phases were barely visible and only the T‐phases were evident, followed by tsunamis that reached islands in the Izu‐Ogasawara Arc and a wide area of the Pacific coast of southwest Japan. Our estimated T‐phase source area coincides with the Sofu Seamount, which was previously unrecognized as an active submarine volcano. A bathymetric survey of the seamount conducted 1 month after the event revealed characteristics of the seamount with a caldera and a central cone. Compared to the bathymetry in 1987, the topography in the caldera had changed significantly such as a crater forming in the central cone. This seamount is likely to be an active volcano. The topographic changes on the caldera‐sized scale that occurred at the caldera can be explained as a source of the October tsunami. Plain Language Summary: On 8 October 2023 (UTC), earthquakes were followed by tsunamis in the Izu‐Ogasawara Arc of Japan that were higher than that estimated from the magnitude of the earthquake. The tsunamis were observed on islands in the Izu‐Ogasawara Arc and a wide area of the Pacific coast of southwest Japanese islands. Strong T‐phases that are underwater acoustic waves were observed accompanying that event. We estimated that the T‐phases originated from the area around the Sofu Seamount, which has not been recognized as an active submarine volcano until now. One month after the event, we conducted a bathymetric survey of the seamount and revealed the characteristics of a caldera and a central cone within the caldera. Compared to the bathymetric data obtained in 1987, the caldera and central cone topography have changed significantly, such as a crater forming in the central cone, indicating that this seamount is likely to have been an active submarine volcano. The topographic changes that occurred at the depth of the caldera (∼1,000 m) and its scale (diameter ∼5 km) can be associated with the source of the tsunami on 8 October 2023. Key Points: A bathymetric survey of the Sofu Seamount was conducted after the unique T‐phase dominant earthquakes and tsunamis on 8 October 2023Compared to data in 1987, the caldera and central cone topography have changed, indicating that this seamount is an active submarine volcanoThe observed seafloor displacement at the caldera scale may have contributed to the source of the tsunami on 8 October 2023 [ABSTRACT FROM AUTHOR]

Kalianda Sub-District is one of the areas that is vulnerable to earthquakes and tsunamis because it is located on the west coast of Sumatra Island and the Sunda Strait has a potency from the eruption of Anak Krakatau Volcano. Increasing population growth also increases the risk of disaster impacts that are difficult to predict. This research aims to analyze the spatial dynamics of tsunami-prone areas in Kalianda District. This research uses multitemporal land cover data, driving data on built-up land development factors, existing roads, slope, distance from the coastline, and distance from rivers. The method used is Cellular Automata Markov Chain which is used to model the development of built-up land, and the Berryman method for tsunami hazard analysis . Based on modeling results for 2031, the type of built land cover will experience a large increase. The tsunami danger level in Kalianda District is dominated by the low level covering an area of 4,741.80 ha, then the high level covering an area of 3,047.29 ha and the medium level covering an area of 1,243.66 ha. According to research results, the number of tsunami-prone areas increases every year. Therefore, we need to improve education and outreach to the public about tsunami dangers and effective evacuation procedures. The development and maintenance of evacuation support infrastructure, as well as the implementation of a reliable early warning system, are also very important to increasing community preparedness for tsunami disasters. [ABSTRACT FROM AUTHOR]

The application of high‐frequency radar as an instrument for assimilating tsunami‐induced current fields is garnering increasing interest. The performance of surface current velocity measurements depends on the azimuthal differences between the crossing radar beams at the measurement points. This study aimed to incorporate the measurement error distributions of the east‐west and north‐south velocity components into tsunami data assimilation based on an optimal interpolation method, assuming Gaussian noise with the time‐invariant and a uniform standard deviation (STD = 5 cm/s) of radial velocity measurements. Through the empirical orthogonal function (EOF) analysis of radar‐derived surface currents in the Kii Channel, Japan, the velocities reconstructed using higher modes (EOFs 16–274) were associated with measurement errors, portraying nonuniform distribution depending on the crossing beam angle of two radar beams. Based on independent fifteen‐time assimilation experiments for two different tsunami scenarios, for a uniform water depth of 500 m, we observed a significant improvement of up to 29% and 0.9% in the assimilation performance (on average) over the along‐coast stations for scenarios with 1‐ and 5‐m maximum initial sea surface heights, respectively. The measurement errors dependent on the crossing beam angle reduced the error‐induced tsunamis, resulting in stable assimilations, with lower STDs in the fifteen‐time assimilation performances. When the STD of Gaussian noise varies with time, it is important to consider the temporal change in the radial velocity measurement errors and/or noise‐filtering techniques, to maintain a certain level of noise intensity. Plain Language Summary: High‐frequency radar is valuable for monitoring tsunamis as it measures tsunami‐induced surface current velocities, not the tsunami height, which is crucial for tsunami evacuation. In this study, we estimated a reasonable tsunami wave height using a data assimilation method incorporating high‐frequency radar measurements with tsunami numerical simulation. To minimize the adverse effects of high‐frequency radar measurement errors and obtain accurate tsunami wave heights, it is essential to estimate the errors appropriately, especially considering their dependency on the radar beam angle. We estimated the beam angle‐dependent errors through a principal component analysis and integrated them into the assimilation process. By doing so, we successfully reproduced the tsunami wave heights, demonstrating an improvement over estimations made under the assumption of constant errors and mitigating the negative impact of measurement errors. Key Points: Measurements of radar‐derived surface current velocities are influenced by the azimuthal difference between crossing radar beamsWe applied the measurement error distribution to tsunami data assimilationThe results suggest that the consideration of measurement error distribution is crucial for improved assimilation performance [ABSTRACT FROM AUTHOR]

In November 1815, the deadliest "natural" disaster in Balinese history was caused by the exceptional combination of multiple natural hazards that occurred simultaneously and cascaded in the present-day province of Buleleng. This major disaster, which is thought to have claimed more than 10,000 lives, has never been scientifically analyzed. The study conducts an in-depth analysis of this cascading disaster, from the root causes and chronology of natural hazards to their environmental and societal effects, by thoroughly examining all available written sources about this event, whether colonial or Indonesian. Seven months after the Tambora eruption, a magnitude 7.3 earthquake, which occurred in the Bali Sea off the northern coast of the island, triggered a very large landslide on the northern flank of the Buyan-Bratan caldera. The initial mass movement evolved into a cohesive debris flow that reached the sea after traveling up to twenty kilometers through Banyumala River Valley and Singaraja City downstream. According to historical accounts, fifteen villages were buried or devastated by the debris flow. The large volume of sediment entering the sea triggered a local tsunami along Buleleng's coast. This geohistorical approach offers a comprehensive overview of various sources describing Singaraja's situation before the crisis, the hazard succession, the cascading hazard intensities, and the short- to long-term impacts on Buleleng. Based on the written sources, Bali took around fifteen years to recover from the 1815 disasters. [ABSTRACT FROM AUTHOR]

Submarine volcanic eruptions can induce major local and regional tsunami hazards through varied source mechanisms. Large‐scale experiments of tsunamis generated by submarine volcanic eruptions are conducted to study the cylindrical wave generation and propagation in a three‐dimensional wave basin. A unique volcanic tsunami generator (VTG) was deployed at the bottom of the wave basin to generate volcanic tsunamis with repeatable and controlled source parameters. The physical modeling is based on the generalized Froude number defined with the VTG velocity and the near source water depth. The pneumatically driven vertical stroke motion generates leading elevation waves in the wave basin. The tsunami waves generated by the VTG are measured with a wave gauge array. The wave maker performance is characterized by the dimensionless leading wave amplitudes and periods. The experimental data show the variations of the leading wave amplitude, period, and celerity along the radial propagation distance. The generated cylindrical waves belong to the weakly nonlinear wave regime in the near field with decaying wave amplitude along radial propagation. The attenuation rate of the leading wave exceeds the range from the linear wave theory in runs with higher Froude numbers. The dimensionless leading wave period increases with the dimensionless propagation distance due to the dispersion relation. Empirical equations for the characteristic wave parameters such as amplitudes and periods are derived. The experimental results contribute to the understanding of volcanic tsunami generation processes and may serve rapid volcanic tsunami hazard assessments as well as the advancement and validation of numerical models. Plain Language Summary: Tsunami hazards generated by non‐tectonic sources such as submarine volcanic eruptions have received more attention recently to understand their generation mechanisms and advance tsunami warning systems. Underwater eruptions with explosive energy can trigger catastrophic tsunamis such as the 1883 Krakatau and 2022 Tonga events. It's generally dangerous to directly observe an eruption and particularly challenging to collect remote sensing field data for underwater or partially submerged volcanoes. In order to understand the tsunami generation, an individual mechanism is isolated. A submarine volcano is physically modeled in the wave basin with a unique pneumatically driven volcanic tsunami generator. The tsunami waves generated with the experimental setup are measured with cameras and wave gauges. Based on the measured data, predictive equations are compared with existing studies. The experimental results can support the development of rapid tsunami hazard assessments for future events. Key Points: A volcanic tsunami generator with pneumatically controllable vertical motion is deployed for physical modeling of point source tsunamisExperiments encompassing submerged, daylighting, and surface piercing scenarios are conducted to measure the cylindrical wave parametersEmpirical equations are proposed to evaluate the wave characteristics of the cylindrical leading elevation waves [ABSTRACT FROM AUTHOR]

The identification of extreme wave events' deposits is of the main importance in the contexts of global warming and coastal geohazards. Specifically, improving the knowledge of this phenomenon is extremely relevant for high populated volcanic oceanic islands. In this paper, we analyse two extreme wave event deposits located on a coastal platform formed by lavas from the 1730–1736 Timanfaya eruption in Lanzarote Island (Spain). The first one consists of a boulder ridge parallel to the coast of approximately 750 m in length and 7 m asl in elevation. These are accumulations of non‐cemented large boulders and sands that extend about 150 m inland from the intertidal zone. The boulders are of basaltic composition, heterometric, sub‐rounded to angular, and they reach sizes up to 3 m of major axis. They are imbricated both inland and seaward, indicating a strong inundation and backwash. The second deposit is a small outcrop of boulders of equal composition and sizes up to 1 m of major axis, reaching an elevation up to 6 m asl, and has been correlated with the former deposit. Here, the boulders were also deposited on the Timanfaya lavas and later covered by lava flows extruded during the 1824 eruption. Therefore, both deposits could be related with a chronologically well‐contrasted event, between 1736 and 1824. The origin of these deposits could be interpreted as an extreme storm or a tsunami. There are no historical records of extreme storms in the Canary Islands for this period, but there is documentary evidence of the tsunamis of 1761 and 1755. Moreover, for the latter, there is documentation that indicates its impact on coastal infrastructures in the Canary Islands, including the western slope of Lanzarote, and therefore, we propose these deposits as the first sedimentary evidence of the 1755 tsunami in the Canary Islands. [ABSTRACT FROM AUTHOR]

In radar signal processing, the pursuit of precise prediction algorithms motivates the exploration of innovative methodologies. This study introduces a pioneering fusion of learning vector quantization (LVQ)- Kalman, merging LVQ with the advanced Kalman filter. The primary aim is to enhance adaptability and robustness, vital in weather monitoring and military surveillance. LVQ, known for its efficacy in pattern recognition and prediction, adjusts prototype vectors iteratively based on input data, ideal for radar signal intricacies. Various LVQ types are incorporated, tailored meticulously for specific radar applications. The Kalman filter, originally for aerospace, excels in tracking and predicting dynamic systems, seamlessly integrated to address uncertainties in radar data. By combining LVQ's pattern recognition with the Kalman filter's adaptability, the fusion aims to create a versatile system navigating radar data intricacies. Applications range from airborne target tracking to weather analysis and military surveillance. The integrated approach offers adaptability and robustness, vital for realworld implementations, particularly in tsunami detection. Future research may explore deep learning to further enhance adaptability. This fusion technique presents significant potential for advancing radar signal processing, promising accurate and adaptive systems, especially in critical applications like tsunami detection. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Indonesian Civil & Environmental Engineering / Jurnal Teknik Sipil & Lingkungan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Indonesian Civil & Environmental Engineering / Jurnal Teknik Sipil & Lingkungan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract When an object moves through the atmosphere, it induces pressure fluctuations. If the scale of the object’s movement spans several hundred meters to several kilometers, the period of the pressure fluctuation will range from several seconds to several tens of seconds, determined by the ratio of the scale to the speed of sound. These pressure fluctuations manifest within the frequency range between audible sound (> 20 Hz) and infrasound (< 20 Hz and > 3 mHz). The infrasonic waves, characterized by their low-frequency nature, present a promising avenue for long-distance remote sensing, particularly in the monitoring of geophysical events with the potential for widespread destruction, such as earthquakes and tsunamis. We developed sensors of both membrane and microphone types to monitor infrasound in lower or higher frequency, respectively. These sensors were installed on the Pacific side of Japan to observe infrasound mainly generated by tsunamis. The key advantage lies in the faster propagation speed of Lamb waves ( $$\sim$$ ∼ 310 m/s) compared to that of tsunami waves ( $$\sim$$ ∼ 200 m/s), making them a valuable precursor for timely detection. By combining with a small MEMS 3-axis accelerometers, this study explores the feasibility of identifying a sudden atmospheric pressure surge within the infrasonic frequency range, following a significant earthquake. The observed surge serves as a crucial indicator of the imminent arrival of large tsunami waves along the shoreline situated between the earthquake’s epicenter and the observation site. The practical implication of this detection methodology is profound, as it could potentially trigger early warning systems, leading to timely and targeted evacuations. These infrasound sensors effectively detected infrasound produced not only by tsunamis but also by volcanic eruptions, meteorite explosions, and so on. This research focuses on the significance of monitoring geophysical events in the infrasound frequency range by demonstrating the development of our infrasound sensors and the natural phenomena captured by these instruments. The study presents observational results based on three types of sensors (INF01LE, INF03, and INF04LE), each exhibiting a flat response within specific frequency ranges: 0.003 to 6.25 Hz, 0.1 to 100 Hz, and 0.1 to 100 Hz, respectively. These sensors have been rigorously tested across various natural phenomena to validate their effectiveness in capturing infrasonic waves. The findings of this research contribute to the growing body of knowledge on infrasonic wave coming from various geophysical disaster perspectives.

The rubble mound (RM) breakwater, which is a prevalent coastal structure worldwide, often faces the significant challenge of tsunami-induced damage. Coastal regions which are characterized by high population density necessitate robust breakwaters to withstand the destructive forces of tsunamis. The most devastating natural hazard that a breakwater could encounter during its lifespan is the tsunami. Past occurrences have revealed vulnerabilities in conventional RM breakwaters leading to failures attributed to the scouring of rubble and seabed caused by excessive seepage during tsunami overflow events. This study presents novel countermeasures aimed at mitigating the potential failure mechanisms induced by tsunamis on RM breakwaters. The proposed countermeasure elements include gabions, crown walls equipped with shear keys, and sheet piles. To assess the efficacy of these innovations, a series of tsunami overflow tests was conducted on small-scale models. The results demonstrated a marked improvement in the stability and resilience of RM breakwaters against tsunamis with the incorporation of these countermeasures. Additionally, numerical simulations were performed to determine the precise mechanisms influencing the behavior of the breakwater during tsunamis. Practical Applications: This study introduces innovative techniques for enhancing the resilience of rubble mound breakwaters against tsunamis, which have significant implications for coastal protection and disaster mitigation efforts worldwide. By incorporating gabion-based countermeasures such as wire cages filled with rocks (gabions), crown walls with shear keys, and sheet piles, substantial improvements were observed in the stability and durability of rubble mound breakwaters during tsunami events. The proposed technique enabled the rubble mound breakwater to withstand Level 1 tsunamis without undergoing any deformations. For coastal communities facing the threat of tsunamis, implementing the proposed novel gabion-based techniques offers tangible benefits in terms of enhanced protection against catastrophic tsunamis. The proposed technique provides cost-effective and adaptable solutions to existing and newly constructed rubble mound breakwaters. Through practical application of the proposed technique, coastal engineers, policymakers, and disaster management agencies can effectively mitigate the risks posed by tsunamis. [ABSTRACT FROM AUTHOR]

Background: Exposure to extreme weatherly events potentially develops mental disorders among affected individuals. Aim: To synthesize the burden of mental disorders following impact of extreme weather events in South-east Asian (SEA) countries. Methods: Proposal was registered in PROSPERO register [CRD42023469788] and reported as per PRISMA-2020 guidelines. Studies reporting prevalence of mental health disorders following extreme weather events from SEA countries during 1990 and 2023 were searched on Embase, PubMed, and Scopus databases. Study quality was assessed using Appraisal tool for Cross-Sectional Studies. Overall pooled prevalence was computed using DerSimonian–Laird method for random-effects model and reported as 95% confidence intervals. Results: On screening 12,046 records, we included 155 studies (2,04,474 participants) for analysis. Overall burden of mental disorders was 35.31% (95%CI: 30.42%–40.21%). In subgroup analysis, studies on cyclones, India, local residents, children and adolescents, rural settings, and community settings reported higher burden of mental disorders. Depression (28.58%; 95%CI: 24.05%–33.1%) and PTSD (29.36%; 95%CI: 26.26%–32.46%) had similar prevalence. Visiting tourists to SEA region experienced fear, fear of recurrence of tsunami, nightmares, and sense of helplessness. Mental health outcomes were relatively higher in studies conducted within 1 year of events. Heterogeneity and possibility of publication bias exists among the reported studies. Conclusion: With the significant rise in episodes of extreme weather events in SEA region over the last three decades, mental disorders are documented in different proportions. We suggest prioritizing well-informed policies to formulate inclusive and resilient strategies on effectively identifying and treating mental health concerns among victims of extreme weather events.

Abstract In recent years, there have been worldwide reports of massive tsunamis, drawing attention to how tsunamis are intensified by submarine landslides triggered by earthquakes. However, precise data on tsunamis caused by submarine landslides are scarce, leading to insufficient information for a thorough discussion of the characteristics of such tsunamis. On the other hand, during the Noto Peninsula earthquake (Mw7.5) that occurred in Japan on January 1, 2024, a nonseismic tsunami distinct from those originating from fault ruptures were observed. To investigate its characteristics, we analyzed tide/wave gauge records, video footage, and tsunami trace heights along the coast of Toyama Bay. Furthermore, we validated scenarios capable of reproducing the observed records using an integrated landslide–tsunami model. It was found that assuming the existence of 5 submarine landslides along the underwater canyons of Toyama Bay enabled the precise explanation of multiple types of data. Additionally, our study revealed that submarine landslides occurred approximately 50 s after the earthquake, coinciding with the peak ground shaking in Toyama Bay. Compared to the seismic tsunami originating solely from the Noto Peninsula offshore fault rupture, the subsequent tsunami triggered by submarine landslides amplified the tsunami height by approximately 30% along Toyama Bay.

The present study is devoted to the analysis of extreme sea level oscillations of the Laptev Sea using the ADCIRC model. The numerical modeling is performed on a high-resolution grid and verified for sea level observations from three tide gauges. We have revealed regional characteristics of extreme sea level oscillations for different parts of the Laptev Sea coast. The maximum total sea level range was 544 cm in Ebelyakh Bay, while the minimum was 267 cm in Khatanga Bay, where maximum tidal ranges were obtained. Some areas in Khatanga Bay and Anabar Bay had maximum tidal ranges exceeding 200 cm. The study provided an estimation of the possible magnitude of coastal flooding by calculating the extreme total and residual sea levels for different return periods: 1, 2, 5, 10, 20, 50, and 100 years. The amplitude of extreme surges calculated for the 100-year return period can exceed 300 cm for several sections of the Laptev Sea coast, with the maximum sea level range being about 680 cm for Anabar and Ebelyakh Bays. [ABSTRACT FROM AUTHOR]

Modeling and simulation have been used to study tsunamis for several decades. We created a review to identify the software and methods used in the last decade of tsunami research. The systematic review was based on the PRISMA methodology. We analyzed 105 articles and identified 27 unique software and 45 unique methods. The reviewed articles can be divided into the following basic categories: exploring historical tsunamis based on tsunami deposits, modeling tsunamis in 3D space, identifying tsunami impacts, exploring relevant variables for tsunamis, creating tsunami impact maps, and comparing simulation results with real data. Based on the outcomes of this review, this study suggests and exemplifies the possibilities of system dynamics as a unifying methodology that can integrate modeling and simulation of most identified phenomena. Hence, it contributes to the development of tsunami modeling as a scientific discipline that can offer new ideas and highlight limitations or a building block for further research in the field of natural disasters. [ABSTRACT FROM AUTHOR]

The tsunami that was triggered by the 2024 Noto Peninsula Earthquake caused severe inundation along the coast on the northeastern tip of the peninsula, propagated over the sea with rough wind waves, and reached the coast and rivers located away from the peninsula. This manuscript presents the results of a field survey and a supplementary analysis for investigating the tsunami characteristics away from the peninsula where rough wind waves had a significant influence on the tsunami behavior. Video images captured by closed-circuit television (CCTV) cameras were used for onsite detection of the tsunami traces and for extracting time-varying water level profiles. Wind waves had little influence on the tsunamis along the lower reaches of the rivers, and the measured tsunami heights were consistent with each other in the nearby field. At most of the survey sites, the highest tsunami traces were created not by the first but by the following tsunami. Along Toyama Bay, the tsunami water levels first decreased within several minutes after the earthquake, and the arrival times for this negative tsunami peak was earlier in the southern part of the bay. These characteristics may indicate the existence of multiple tsunami sources inside Toyama Bay. [ABSTRACT FROM AUTHOR]

Recent catastrophic tsunamis, such as the 2004 Indian Ocean and 2011 Tohoku events, have underscored the need for resilient coastal infrastructure. Field investigations in the aftermath of these tsunamis have consistently identified local scour around structures as a critical factor contributing to their failure. Local scour refers to the erosion or removal of sediment in the vicinity of a structure, triggered by the unsteady water flow associated with tsunami inundation. The recognition of the significance of this phenomenon, juxtaposed with the current deficiency of detailed and systematic design guidelines that incorporate the ramification of local scour, has spurred advancements in this area of research. This study has meticulously reviewed state-of-the-art studies on tsunami-induced local scour around structures. The existing design guidelines have been critically assessed, pinpointing their limitations and areas that require further elucidation. Moreover, this critical analysis delineates the current knowledge gaps and outlines prospective directions for future research endeavors aimed at enhancing the resilience of coastal infrastructure, with a particular focus on mitigating the effects of local scour. This comprehensive review aims to deepen the understanding of tsunami-induced local scour and promote more effective, evidence-based design strategies to mitigate the risk of structural failure in high-risk coastal areas. [ABSTRACT FROM AUTHOR]

On January 1 2024, at 16:10 JST, an earthquake of Mw 7.5 occurred underneath the Noto Peninsula of Ishikawa Prefecture, Japan. This event caused a cascading disaster impact on cities in the Noto Peninsula through a series of strong earthquake shakes, strong ground motions, slope failures, liquefaction, fire, and tsunamis. The tsunami first reached Suzu City a few minutes after the earthquake, eventually affecting approximately 340 km of the coast from the Ishikawa to Niigata Prefectures. The Coastal Engineering Committee of the Japan Society of Civil Engineers conducted an organized post-event field survey to understand the impact of tsunamis on land. This study summarizes the post-event field survey results and provides a general understanding of tsunami behavior and damage using measured tsunami inundation and run-up heights. [ABSTRACT FROM AUTHOR]

Tsunamis, though infrequent, wield devastating power on coastal regions, necessitating accurate simulation techniques to comprehend their impact and enhance disaster preparedness. Despite significant advances in modern computational fluid dynamics, these simulations continue to pose considerable challenges, including numerical intricacies and substantial computational costs. Owing to its remarkable computational efficiency and high performance, the lattice Boltzmann method (LBM) is being increasingly used for simulating large-scale tsunamis. This review paper systematically surveys the application of the free-surface flow model using the LBM to simulate tsunamis, covering its theoretical underpinnings, numerical implementation, and validation against real-world events. Furthermore, the paper discusses challenges, limitations, and ongoing developments in the application of the LBM for tsunami simulations, elucidating avenues for future research. By amalgamating insights from diverse studies, this review underscores the role of the LBM as a tool for advancing our understanding of tsunamis and increasing coastal resilience. HIGHLIGHTS: Lattice Boltzmann method investigated for tsunami simulations Challenges, limitations, and ongoing developments in tsunami simulation discussed Systematical survey of the application of the free-surface flow model Theoretical underpinning, numerical implementation, and real-world validation [ABSTRACT FROM AUTHOR]

This work examines tsunami run-up processes within a building array partially sheltered by a high-elevation, finite length, seawall. Work was performed using numerical modeling of 2D shallow water equations with varying seawall length, wave height, time scale, and structure size. Inundation depth and flow velocity were output at many locations of interest throughout the structural array. The most important influence on results when compared to the no-wall case was the sheltering or clearance angle as defined from the end of the wall. Behind the wall, inundation depth and cross-shore velocity declined significantly as sheltering angles increased (more sheltered). Alongshore inundation velocity (parallel to the seawall) increased strongly with increasing sheltering angle. A longer wave time scale resulted in significant increase in inundation depth and velocity especially at locations sheltered by the wall. Larger structure size or blockage ratio also led to increased inundation depth and flow velocity. However, varying wave height gave little change in inundation and velocity patterns. These results will serve to provide a better understanding of the wave inundation within a coastal urban region in a tsunami event when the seawall is breached, as well as the influence of coastal structure size and spacing on the tsunami inundation. [ABSTRACT FROM AUTHOR]

The evaluation of the impact of tsunami-borne debris collisions is important in designing tsunami-resistant structures and quantifying the risk for regional and industrial facilities located along the coast. Consequently, research on this topic is being actively conducted. Methods that evaluate debris behavior during tsunamis, including collision probability, velocity, and force, as well as the necessary parameters for these evaluations, are invaluable from a practical perspective and are being implemented through their incorporation into guidelines. Although research continues and evaluation techniques are maturing, identifying future challenges remains essential. This review article covers a wide range of technologies, both those already in use and those under development, and the physical processes that should be considered in these evaluations. It summarizes the applicability of evaluation methods based on accuracy, computational cost, and practicality, and clarifies the technologies currently available. The review identifies issues for future research, particularly the development of a probabilistic evaluation framework, which is highlighted as an area requiring further research. This review serves not only as a collection of practical findings but also as a basis for developing advanced evaluation techniques for tsunami-induced debris collisions, thereby contributing to the advancement of future structural design and the enhancement of local disaster preparedness against tsunamis. [ABSTRACT FROM AUTHOR]

Effective disaster management can help mitigate both human and financial damage. However, the absence of appropriate disaster preparedness and management efforts can increase the vulnerability of international tourists to natural disasters. International tourists differ from residents and local tourists in various ways, including limited knowledge of disasters and disaster responses, use of different languages, limited access to signs, and shelter locations and evacuation routes. This study developed an agent-based evacuation model to determine the differences in evacuation behaviors among international tourists, residents, and local tourists during a tsunami. Further, it clarified the impact of both soft and hard countermeasures such as information provision and shelter capacity expansion. Our case study was conducted in the Minato Bay area in Osaka, Japan. The simulation results revealed disparities in the evacuation behaviors between international tourists and residents in the arrival times at shelters. The enhanced sign accessibility and provision of signs in multiple languages significantly reduced the arrival time of international tourists at shelters. Consequently, it is necessary to improve disaster management plans that ensure information provision in multiple languages and the establishment of temporary shelters near tourism spots to support international tourists during disaster evacuation. • Disparities exist in the evacuation behaviors of international tourists and residents. • International tourists following other evacuees take more time to reach shelters. • Enhanced sign accessibility reduces international tourists' arrival times. • Information provision in multiple languages reduces international tourists' arrival times. [ABSTRACT FROM AUTHOR]

Large amplitude and unexpected waves are a regular source of natural disasters. Among them, impulse waves generated by landslides can represent a significant threat. Therefore, predicting and measuring the generation of such waves is essential. In this study, the phenomenon is modeled by a 2D‐experimental setup using a steady non‐uniform granular flow along a slope as a forcing wave generator. The present device provides a continuous supply of grains to avoid finite volume effects, as the part of the landslide actually involved in the wave generation strongly depends on the configuration and is not necessarily available in geophysical events. This system consists of an energy transfer between the granular flow and the wave generation which is characterized by a Froude number. It is found that the latter cannot be defined only based on the dry flow properties to characterize the wave. In particular, the dynamics underwater influence wave generation during a finite time. Accordingly, the present study shows that the wave maximum amplitude is governed by a newly defined Froude number, based on both dry and underwater granular flow properties. Moreover, it is shown that the granular deposit, specifically its runout, can be thought as a proxy of the immersed granular dynamics as long as the impact properties are still considered. Plain Language Summary: Landslides can cause huge waves if they impact the surface of an ocean, a lake or a sea. The properties of the landslide as well as the wave formation are complex features. In this study, an attempt to model this phenomenon experimentally at the laboratory scale is made, using a controlled granular flow impacting water in a 2D wave channel. The rapid evolution of this system requires a camera in order to extract the dynamics of both the wave and the granular material, simultaneously. From these measurements, it is shown that the wave and the granular flow are strongly linked at early stages. Moreover, after the maximum wave amplitude is reached, the wave propagates freely and may influence the granular deposit. This study proposes to link these processes and the wave characteristics to a single dimensionless parameter, which is a combination of Froude numbers. Key Points: A detailed analysis of new impulse wave experiments using a continuous granular supply is presented to highlight the wave‐granular couplingThe wave maximum amplitude is shown to evolve non‐monotonically with the deposit runoutConsidering wave‐granular interaction, a newly defined Froude number allows to accurately predict the wave characteristics [ABSTRACT FROM AUTHOR]

Tsunamis are rare events involving several complex physical phenomena. Due to this complexity and the relative scarcity of observations, tsunami research makes extensive use of numerical simulations. For seismogenic tsunamis, the source is often modeled as an instantaneous sea‐floor displacement (IS), while the tsunami propagation and inundation is computed through a shallow water approximation (SW). Here, we investigate what is the best tsunami inundation modeling strategy for different realistic earthquake source size and duration. We use 1D earthquake‐tsunami coupled simulations of large M > 8 earthquakes in Tohoku‐like subduction zone to test for which conditions the IS and/or the SW approximations can simulate with enough accuracy the tsunami evolution. We use as a reference a time‐dependent (TD), multi‐layer, non‐hydrostatic (NH) 1D model. Source duration, and size, are based on 1D dynamic rupture simulations with realistic stress drop and rigidity. We show that slow ruptures, generating slip in the shallow part of subduction zones (e.g., tsunami earthquakes), and very large events, with an along‐dip extent comparable with the trench‐coast distance (as occurs for megathrust events) require a TD‐NH modeling, especially for regions with steep coastal bathymetry. Conversely, deeper, higher stress‐drop events can be modeled through an IS‐SW approximation. We finally show that: (a) steeper bathymetries generate larger runups and, (b) a resonant mechanism emerges with runup amplifications associated with larger source size on flatter bathymetries. These results, obtained with 1D modeling, can serve as a guide for the appropriate 2/3D simulation approach for applications ranging from fundamental tsunami science to computational‐intensive hazard assessments. Plain Language Summary: In the last two decades, tsunamis originated by large earthquakes have generated major damage and, according to the World Health Organization, more than 250 k casualties (more than 200 k due to the 2004 Indian Ocean tsunami). Strategies to quantify and mitigate the associated risk are based on numerical simulations of the physical processes regulating the generation, propagation of the waves and subsequent flooding on the coast. These simulations require significant computational resources. To make simulations more affordable, numerous approximations are introduced that need to be tested. In this work, we studied which earthquakes, depending on the speed at which they deform the sea bottom when they trigger a tsunami, and on how big they are, require a more detailed modeling approach, and which ones, instead, might be accurately simulated through approximated approaches. We also show how such findings are related to different bathymetric characteristics near the coast and inland, which may enhance or reduce the tsunami effects. Key Points: Slow and large ruptures (e.g., tsunami earthquakes and megathrust) require a time‐dependent, non‐hydrostatic modelingDeeper, high stress‐drop earthquakes might be modeled through an instantaneous source, shallow water approximationInundation depends on bathymetric features: larger inundations on steeper depth gradients and resonant runup amplifications are observed [ABSTRACT FROM AUTHOR]

People living in coastal areas have the advantage of accessing a high level of ecosystem services, but are also exposed to the dangers inherent in living by the sea in an area prone to natural disasters. To achieve sustainable utilization of the high ecosystem services of coastal areas, establishment of an effective marine policy based on regional characteristics of human–nature interactions is essential. We compared the structure of perceived satisfaction for five components of human well-being ('Security', 'Basic material for a good life', 'Good social relations', 'Health', and 'Freedom of choice and action') derived from coastal ecosystem services among three sites in Japan (Wakasa, Sanriku, and Shima) that share the same natural and social backgrounds: highly dependent on fisheries industry, located in the same climate regime (temperate zone), and have similar topographical features (ria coast). Structural equation modeling using the results from questionnaire surveys showed that the three sites shared a common basic structure of the interactions among the five components of human well-being. However, the intensity of interactions among components differed among the three sites. Questionnaire surveys on anxiety about natural disasters and future access to marine ecosystem services were simultaneously conducted at the three sites. The site-specific anxieties were responsible for the difference in the interactions among the five components of human well-being. We propose a method that quantitatively evaluates both positive (satisfaction) and negative (anxiety) aspects of respondents' subjective assessment as a useful tool for understanding the diversity of human–nature interactions caused by the region-specific natural and social backgrounds of coastal areas. [ABSTRACT FROM AUTHOR]

This study assesses physical infrastructure vulnerability for infrastructure network components exposed during the 2015 Illapel tsunami in Coquimbo, Chile. We analyse road and utility pole vulnerability to damage, based on interpolated and simulated tsunami hazard intensity (flow depth, flow velocity, hydrodynamic force and momentum flux) and network component characteristics. A Random Forest Model and Spearman's Rank correlation test are applied to analyse variable importance and monotonic relationships, with respect to damage, between tsunami hazards and network component attributes. These models and tests reveal that flow depth correlates higher with damage, relative to flow velocity, hydrodynamic force and momentum flux. Scour (for roads and utility poles) and debris strikes (for utility poles) are strongly correlated with damage. A cumulative link model methodology is used to fit fragility curves. These fragility curves reveal that, in response to flow depth, Coquimbo roads have higher vulnerability than those analysed in previous tsunami event studies, while utility poles demonstrate lower vulnerability than with previous studies. Although we identify tsunami flow depth as the most important hydrodynamic hazard intensity metric, for causing road and utility pole damage, multiple characteristics correlate with damage and should also be considered when classifying infrastructure damage levels. [ABSTRACT FROM AUTHOR]

Background: Exposure to extreme weatherly events potentially develops mental disorders among affected individuals. Aim: To synthesize the burden of mental disorders following impact of extreme weather events in South-east Asian (SEA) countries. Methods: Proposal was registered in PROSPERO register [CRD42023469788] and reported as per PRISMA-2020 guidelines. Studies reporting prevalence of mental health disorders following extreme weather events from SEA countries during 1990 and 2023 were searched on Embase, PubMed, and Scopus databases. Study quality was assessed using Appraisal tool for Cross-Sectional Studies. Overall pooled prevalence was computed using DerSimonian-Laird method for random-effects model and reported as 95% confidence intervals. Results: On screening 12,046 records, we included 155 studies (2,04,474 participants) for analysis. Overall burden of mental disorders was 35.31% (95%CI: 30.42%-40.21%). In subgroup analysis, studies on cyclones, India, local residents, children and adolescents, rural settings, and community settings reported higher burden of mental disorders. Depression (28.58%; 95%CI: 24.05%-33.1%) and PTSD (29.36%; 95%CI: 26.26%-32.46%) had similar prevalence. Visiting tourists to SEA region experienced fear, fear of recurrence of tsunami, nightmares, and sense of helplessness. Mental health outcomes were relatively higher in studies conducted within 1 year of events. Heterogeneity and possibility of publication bias exists among the reported studies. Conclusion: With the significant rise in episodes of extreme weather events in SEA region over the last three decades, mental disorders are documented in different proportions. We suggest prioritizing well-informed policies to formulate inclusive and resilient strategies on effectively identifying and treating mental health concerns among victims of extreme weather events. [ABSTRACT FROM AUTHOR]

"Resilience" is the ability to recover after being affected by a disaster or accident. Companies are expected to be resilient against accidents and disasters; however, no method comprehensively evaluates corporate resilience. As a preparation for developing such an evaluation method, this study examines the 13 Resilience Indicators developed by "Resilient Organisations" as one of the models for organizational resilience to assess whether it comprehensively covers the factors that contribute to corporate resilience. This study compares the indicators with past accidents and disaster cases. Consequently, the study determined that the 13 Resilience Indicators do not explicitly cover the following four factors: (1) risk diversification related to external resources such as suppliers, (2) prompt decision-making and action, (3) countermeasures to protect corporate reputation, and (4) a never-give-up attitude. It cannot be said that this is a definitive conclusion, as subjectivity intervenes in various ways in the examination process. However, this study identified factors that should be considered while developing a model that comprehensively includes factors that contribute to corporate resilience. [ABSTRACT FROM AUTHOR]

Tsunami vertical evacuation (TVE) buildings have the potential to save many human lives in countries exposed to near-field tsunamis. Up to now, TVE research has examined three main topics separately: shelter siting, building benchmarks, and decision-making by evacuees. This study aims to integrate these topics to develop more comprehensive TVE planning frameworks. To this, we examined a catastrophic tsunami evacuation scenario in Viña del Mar, Chile. First, we developed an agent-based model to estimate potential human fatalities in the case of a fully horizontal evacuation. Second, we designed an immersive VR experience, which we applied to a sample of 151 people in the city to collect their potential TVE decision-making, which allowed us to identify 11 buildings that could serve as TVE shelters. Lastly, we incorporated this new evacuation system into the former agent-based model to assess the potential impact of vertical evacuation. Our findings showed that while fatalities ranged from 50 to 72% of the population in the fully horizontal scenario, the inclusion of TVE buildings might decrease human losses by 6.5–13.7%. Complementary questionnaires administered to participants highlighted their lack of previous experience in real-world evacuations (only 45.69% had previously experienced a tsunami-related evacuation process), as well as their knowledge about how to proceed in the case of a future emergency (62.91% declared that they knew where to go during an evacuation). [ABSTRACT FROM AUTHOR]

A tsunami is a sequence of powerful waves or surges primarily resulting from underwater earthquakes. Creating tsunami vulnerability maps is of utmost importance to develop effective strategies for mitigating potential damage caused by future tsunamis. This article focuses on areas (Indian subcontinent) severely affected by the 2004 Indian Ocean tsunami. Utilizing geographic information system (GIS)-based tools, the authors employed geospatial cell-based modeling and used a multicriteria decision-making tool, an analytical hierarchy process (AHP), to develop the final inundation map. Using the digital elevation model and Environmental Systems Research Institute (ESRI) land-cover data, the authors created the elevation, slope, coastal proximity, flow accumulation, and land-use land-cover (parameters) map. Areas with a higher risk of tsunami impact are predominantly situated along the coastline with a descending terrain. The presence of waterways and lower elevations intensifies the impact of tsunamis. Regions classified under very high or high vulnerability are more likely to be inundated by the tsunami. The final vulnerability map of Nagapattinam shows that 166.455 km2 of the region is highly vulnerable to a tsunami. Similarly, Kanyakumari, Cuddalore, Karaikal, and Chennai show 37.6516 km2 , 245.641 km2 , 35.7128 km2 , and 35.6306 km2 , respectively, under very high vulnerability. The findings of this study serve as fundamental information for disaster mitigation and urban planning in coastal regions. The research introduces a novel approach to assess areas susceptible to tsunami inundation, utilizing a vulnerability map generated through remote sensing and spatial multicriteria analysis. Furthermore, the parameters employed closely resemble those used in actual inundation mapping, adding to the practicality and reliability of the results. Village maps of the selected area are superimposed on the final vulnerability map to understand the villages vulnerable to tsunamis better. The final vulnerability maps can be used for strategic mitigation during an actual event and to be prepared for future disasters. [ABSTRACT FROM AUTHOR]

The tsunami disaster in Palu, Indonesia, on September 28, 2018, caused many casualties and damage along Palu Bay, Indonesia. Prior to the tsunami, an earthquake was recorded 25 km northeast of Donggala. The analysis suggests that the tsunami was triggered by a landslide beneath the waters of Palu Bay. The investigation then focused on the earthquake’s impact on the tsunami. This study conducts simulations to discern the dominant causes of tsunamis, comparing the effects of landslides with earthquakes. Three distinct tsunami sources were identified: earthquake-only (T-E), earthquake and submarine landslide (T-EL), and submarine landslide-only (TL). Interpretation of tsunami source parameters for underwater landslides is carried out accurately. A nesting grid numerical method was employed to increase resolution and accuracy in the simulations. This study accurately interprets tsunami source parameters using data from the Bathymetry National Data-Geospatial Information Agency (185 m resolution) and the field survey data from Baruna Jaya IV-BPPT Research Vessel Indonesia (25 m resolution), thereby contributing to the creation of a tsunami inundation model map. This map serves to inform preparedness efforts and guide recommendations for infrastructure development in the Palu Bay area. The tsunami inundation model map is verified with field data and estimated using tide gauge monitoring data. The characteristics of the tsunami waves on September 28, 2018, reflect a T-EL-type tsunami source, while the T-L type source produces tsunami waves with longer periods compared to earthquake-generated tsunamis (T-EL). The T-E type, located on land, had minimal influence in causing the tsunami, despite the destructive potential of the shallow-depth M7.5 earthquake. [ABSTRACT FROM AUTHOR]

Tsunami disaster mitigation is essential to reduce the possibility of negative impacts on human life by using ecologically acceptable alternatives. In line with the mitigation efforts, it is essential to focus on strategies such as reducing the risk of casualties and planning for coastal development. An effective method includes the implementation of coastal risk mapping for tsunami disasters. Therefore, this study aimed to determine the propagation and run-up modeling of tsunami waves, as well as evaluate the timing and extent of inundation, and identify affected areas, providing basic information for mapping tsunami risk and vulnerability. Geospatial analysis adopting stacking methods with integrated weighting was applied, using physical topography data as a basis. The results showed that the fault from the earthquake scenario, triggering a tsunami, led to elevated water levels in the southern area. This was attributed to the upward orientation of the fault in the southern area, causing higher waves. Specifically, wave height in the southern area reached a maximum of 8 meters, with the minimum wave value recorded at -4. Tsunami modeling presented a height of 22 meters, resulting in a run-up affecting an area of 965.96 Ha. In conclusion, this study provided an important contribution to the development of the basic theory related to the tsunami risk and vulnerability model. [ABSTRACT FROM AUTHOR]

Owing to the rare occurrence of tsunamis in the Arabian Sea, and the lack of reliable records on them, tsunami preparedness has not been prioritized in plans for the development of coastal cities in the Middle East. However, an increase in the number of earthquakes in the region in the recent past has highlighted the vulnerability of low-lying coastal areas to tsunamis. We investigate the potential of date palm forests to mitigate tsunamis in the Middle East. Experiments were conducted at a scale of 1:100 to assess the effectiveness of forests in reducing the intensity of tsunamis. The reflection at the front of the forest was negligibly small when the depth of flow was lower than the height of the canopy, and increased with the height of the tsunami wave when the depth of flow was higher than the height of the canopy. This shows that the structure of the canopy of date palm trees is key to reducing the energy of the tsunami. The reduction in the maximum depth of flow behind the forest increased with the height of the tsunami when the forest was longer than 120 m. The largest reductions obtained in the depth and velocity of flow behind the forest were 37% and 40%, respectively, when the forest was 180 m long and the tsunami wave was 7 m high. The results suggest that a date palm forest with a length of at least 150 m on flat ground can mitigate tsunamis in the Middle East. [ABSTRACT FROM AUTHOR]

Memorial facilities are one of the crucial places where citizens conduct activities facilitating disaster risk reduction (DRR). However, previous studies have primarily focused on the post-construction phase of official memorial facilities, neglecting the citizen activities collaborating with the official memorial construction process before and during the construction process. This research gap is important considering the urgency of disaster-affected regions to recover from spatial, social, and psychological voids while working towards the goal of DRR, including the efforts of citizens in the official efforts. This study addresses this gap by examining the case of the official memorial park in Ishinomaki, Tohoku region, following the Great East Japan Earthquake. Here, local citizens actively participated in activities before, during, and after park construction, engaging with official efforts. Data were gathered from various online sources to capture activity, space, and management information. Employing a mixed methods research approach, we conducted both quantitative analysis, counting labels of structural coding, and qualitative description of original texts. Our findings reveal that fostering mutual respect built on communication and collaborative tree-planting activities were crucial for maintaining the pre-existing citizen activities and collaborative construction during the official construction period. Additionally, the implementation of a collaborative regulation system was vital for integrating and managing spontaneous citizen activities to achieve the park's intended objectives post-opening. In conclusion, we highlighted a framework elucidating the mechanisms through which these processes contribute to DRR across key phases of disaster risk management: preparedness, prevention, response, and recovery (PPRR). These insights are important in guiding efforts to engage citizens in DRR initiatives through recovery and reconstruction facilitated by memorial facilities. [ABSTRACT FROM AUTHOR]

Este estudio explora el discurso de los actores barriales en la Parroquia José Luis Tamayo del Cantón Salinas, sobre la gestión de riesgos ante desastres naturales específicamente terremotos y tsunami. Se enfatiza la importancia de la participación comunitaria en la toma de decisiones para garantizar su seguridad. El objetivo principal es valorar cómo los actores barriales perciben la preparación de la comunidad en este contexto. Se empleó un enfoque cualitativo y metodología deductiva, realizando un focus group con los actores locales. Los resultados destacan la relevancia del trabajo de las instituciones gubernamentales y no gubernamentales en la localidad, así como el acceso a información pertinente. Sin embargo, se identifica un déficit en el involucramiento de los habitantes, quienes muestran falta de conocimiento sobre los riesgos y las acciones a seguir durante un evento. Este hallazgo subraya la necesidad de fortalecer la educación y la capacitación comunitaria en gestión de riesgos.

Thirteen years have elapsed since the Great East Japan Earthquake of March 2011. Approximately 30,000 evacuees remain. Various reconstructions in the disaster area are currently ongoing. More than 20 years have been taken to complete the decommissioning the nuclear reactors. This study aims to develop a method for studying and following up on the health and health-related states of the victims and the disaster area using the International Classification of Functioning, Disability and Health (ICF). We adopted two newspapers with adequate personal information from the interviewees and qualitatively analysed the content of interviews of 1,910 victims (1,116 male and 794 female; age range: 1–98). The responses of each interviewed victim were coded into three components of ICF (Body Functions, Activities and Participation and Environmental Factors). We obtained 7,812 ICF codes describing the victims’ conditions and the disaster area. Of these, 55 high-frequency codes were quantitatively selected. They characteristically represented suffering caused by different elements of the calamity: the earthquake, the tsunami and the nuclear power plant accident. We noted the shortcomings of ICF during disasters, developed a new method, proposed the idea of a ‘disaster ICF’ in the process and discussed its applications.

Abstract The application of high‐frequency radar as an instrument for assimilating tsunami‐induced current fields is garnering increasing interest. The performance of surface current velocity measurements depends on the azimuthal differences between the crossing radar beams at the measurement points. This study aimed to incorporate the measurement error distributions of the east‐west and north‐south velocity components into tsunami data assimilation based on an optimal interpolation method, assuming Gaussian noise with the time‐invariant and a uniform standard deviation (STD = 5 cm/s) of radial velocity measurements. Through the empirical orthogonal function (EOF) analysis of radar‐derived surface currents in the Kii Channel, Japan, the velocities reconstructed using higher modes (EOFs 16–274) were associated with measurement errors, portraying nonuniform distribution depending on the crossing beam angle of two radar beams. Based on independent fifteen‐time assimilation experiments for two different tsunami scenarios, for a uniform water depth of 500 m, we observed a significant improvement of up to 29% and 0.9% in the assimilation performance (on average) over the along‐coast stations for scenarios with 1‐ and 5‐m maximum initial sea surface heights, respectively. The measurement errors dependent on the crossing beam angle reduced the error‐induced tsunamis, resulting in stable assimilations, with lower STDs in the fifteen‐time assimilation performances. When the STD of Gaussian noise varies with time, it is important to consider the temporal change in the radial velocity measurement errors and/or noise‐filtering techniques, to maintain a certain level of noise intensity.

Abstract On 8 October 2023 (UTC), unique earthquakes occurred in the Izu‐Ogasawara Arc, Japan, in which the P‐ and S‐phases were barely visible and only the T‐phases were evident, followed by tsunamis that reached islands in the Izu‐Ogasawara Arc and a wide area of the Pacific coast of southwest Japan. Our estimated T‐phase source area coincides with the Sofu Seamount, which was previously unrecognized as an active submarine volcano. A bathymetric survey of the seamount conducted 1 month after the event revealed characteristics of the seamount with a caldera and a central cone. Compared to the bathymetry in 1987, the topography in the caldera had changed significantly such as a crater forming in the central cone. This seamount is likely to be an active volcano. The topographic changes on the caldera‐sized scale that occurred at the caldera can be explained as a source of the October tsunami.