Tsunami Model Research Articles

The Multi‐Segment Complexity of the 2024 MW ${M}_{W}$ 7.5 Noto Peninsula Earthquake Governs Tsunami Generation

AbstractThe 1 January 2024, moment magnitude 7.5 Noto Peninsula earthquake ruptured in complex ways, challenging analysis of its tsunami generation. We present tsunami models informed by a 6‐subevent centroid moment tensor (CMT) model obtained through Bayesian inversion of teleseismic and strong motion data. We identify two distinct bilateral rupture episodes. Initial, onshore rupture toward the southwest is followed by delayed re‐nucleation at the hypocenter, likely aided by fault weakening, causing significant seafloor uplift to the northeast. We construct a complex multi‐fault uplift model, validated against geodetic observations, that aligns with known fault system geometries and is critical in modeling the observed tsunami. The simulations can explain tsunami wave amplitude, timing, and polarity of the leading wave, which are crucial for tsunami early warning. Upon comparison with alternative source models and analysis of 2000 multi‐CMT ensemble solutions, we highlight the importance of incorporating complex source effects for realistic tsunami simulations.

Numerical Modeling of Tsunamis Generated by Subaerial, Partially Submerged, and Submarine Landslides

Using the existing two-dimensional experimental data and Open-source Fields Operation and Manipulation (OpenFOAM) software, this study performs a comprehensive comparative analysis of three types of landslide-generated tsunamis (subaerial, partially submerged, and submarine). The primary objective was to assess whether numerical simulations can accurately reproduce the experimental results of each type and to compare the predictive equations of the tsunami amplitudes derived from experimental and simulated data. The mesh size and dynamic viscosity parameters were initially optimized for a specific partially submerged landslide tsunami scenario and then applied across a broader range of experimental scenarios. Most of the simulated wave amplitudes remained within the 50% error margin, although significant discrepancies were observed between landslide types. When focusing on the crest amplitude of the first wave, the simulations of subaerial landslides least deviated from the experimental data, with a mean absolute percentage error of approximately 20%, versus approximately 40% for the partially submerged and submarine landslides. The predictive equations derived from the simulations closely matched those from the experimental data, confirming that OpenFOAM can effectively capture complex landslide–tsunami dynamics. Nonetheless, variations in the coefficients related to slope angles highlight the need for further calibration to enhance the simulation fidelity.

Physical Modeling of Tsunamis Generated by Submarine Volcanic Eruptions

AbstractSubmarine 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.

Animation tsunami modelling in 3D to determine shelter and evacuation routes

ABSTRACT Indonesia is located on the Pacific Ring of Fire, making the country prone to earthquakes and tsunamis. Indonesia, especially the southern region of Java, has the potential to be hit by a megathrust earthquake triggering waves much higher than before. Determining evacuation routes and locations as a part of disaster management is essential to avoid many fatalities. This research aims to determine evacuation routes and shelters using photogrammetry-based 3D animation. This paper applied experimental research for modelling and simulation approach with the stages of generating a 3D orthomosaic map, predicting tsunami magnitude, determining the height and distribution of waves, modelling and simulating 3D animation as well as marking evacuation routes and shelter locations. 3D orthomosaics are created based on aerial photos (UAV) drones. Future tsunami data are used to estimate the extent and depth of inundation that may occur. This research uses the Teluk Penyu area in Cilacap, Indonesia, as a study site. The tsunami disaster caused by an earthquake magnitude 7.8 centred in the south of West Java hit this city in 2006. This research produces a 3D animation model that can visualise the extent and depth of tsunami inundation to determine evacuation routes and shelter buildings.

Forearc crustal faults as tsunami sources in the upper plate of the Lesser Antilles subduction zone: the case study of the Morne Piton fault system

Abstract. In this study, alternatively to the megathrust, we identify upper-plate normal faults orthogonal to the trench as a possible tsunami source along the Lesser Antilles subduction zone. The Morne Piton fault system is such a trench-perpendicular upper crustal fault at the latitude of Guadeloupe. By means of seismic reflection, high-resolution bathymetry, remotely operated vehicle (ROV) imaging and dating, we reassess the slip rate of the Morne Piton fault since 7 Ma, i.e., its inception, and quantify an average rate of 0.25 mm yr−1 since ca. 1.2 Ma. This result divides by two previous estimations, increases the earthquake time recurrence and lowers the associated hazard. The ROV dive revealed a metric scarp with striae at the toe of the Morne Piton fault system, suggesting a recent fault rupture. We estimate a fault rupture area of ∼ 450–675 km2 and then a magnitude range for a maximum seismic event around Mw 6.5 ± 0.5, making this fault potentially tsunamigenic as the nearby Les Saintes fault responsible for a tsunami following the 2004 Mw 6.3 earthquake. Consequently, we simulate a multi-segment tsunami model representative of a worst-case scenario if all the identified Morne Piton fault segments ruptured together. Our model provides clues for the potential impact of local tsunamis on the surrounding coastal area as well as for local bathymetric controls on tsunami propagation. We illustrate that (i) shallow-water plateaus act as secondary sources and are responsible for a wrapping of the tsunami waves around the island of Marie-Galante; (ii) canyons indenting the shallow-water plateau slope break focus and enhance the wave height in front of the most touristic and populated town of the island; and (iii) the resonance phenomenon is observed within the Les Saintes archipelago, showing that the waves' frequency content is able to perturb the sea level for many hours after the seismic rupture.

Enhancing tsunami modelling by using N-waves and the measured topography of coral reef: A study in the South China Sea

The South China Sea (SCS), located at the intersection of two major tectonic plates and near the Manila Fault Zone, is a region highly susceptible to earthquakes and tsunami activities. To develop a more comprehensive and reliable understanding of tsunami behaviours over coral reefs, this study employs the actual topography of a coral reef in the SCS and N-wave theory for the numerical simulation, encompassing the entire tsunami life cycle. Utilizing the open-source solver OlaFlow, driven by the Reynolds-averaged Navier-Stokes (RANS) equations, this study performs a series of numerical simulations of N-wave tsunamis considering the measured topography of the coral reef, as well as the real dimension of an engineering defence structure on the top of the coral reef. The adopted tsunami parameters are equivalent to an earthquake with a moment magnitude of 7.1. The simulations focus on the impact of wave profiles and initial static water levels on the propagation and evolution of tsunamis. Numerical simulations reveal that tsunami profiles, water depth, and topography significantly influence the tsunami dynamics, notably in the waveform transformation, the relationship between wave height and trough-to-peak ratio, and the topographic effects on the wave energy dissipation. These results highlight the critical need to incorporate factors such as tsunami profiles, dispersion, and realistic topography into tsunami predictive models for the purpose of more reliable hazard evaluation and the development of effective coastal defences.

Source characteristics of the 2006 Pingtung earthquake doublet off southern Taiwan and the possible contribution of submarine landslides to the Tsunami

On 26th December 2006, two successive large earthquakes of Mw ∼7.0, occurred offshore southwest Taiwan, being 8 min apart, known as the 2006 Pingtung earthquake doublet. The earthquakes triggered a hazard chain consisting of regional-scale tsunamis, submarine landslides, and turbidity currents. The tsunami waves with moderate height (10–60 cm) were recorded by 12 tide gauges along southern Taiwan, Guangdong, and Fujian provinces. Submarine landslide-induced turbidity currents inflicted widespread damage to telecommunication cables across the Kaoping Canyon and Manila Trench. Although the mechanisms of the individual hazard in the chain have been investigated previously, the interaction mechanisms and the causal relationship among them remain unclear due to the complexity of the dynamic process. Here, with the best available instrumental records of these events, we first reexamined the earthquake doublet's source characteristics and obtained the earthquake source models using regional seismic waves, high-rate GPS displacements, and strong motion waveforms. We then conducted forward tsunami modeling, along with spectral analysis of the tide gauge records and backward tsunami ray tracing technique, to gain insight of the hydrodynamic features of tsunamis and the contribution of landslides to tsunami generation. The main findings can be summarized as follows. The centroid depth of the first earthquake was found to be ∼28 km, which is shallower than the local CWB catalog suggested. The slip distribution was characterized by two close slip patches, ranging over depths of 15–35 km and occupying 40 km along the strike. The shallower focal depth and normal-faulting mechanism can well explain the recorded tsunami waves. Notably, wave analysis suggests that tsunami waves induced by landslides may have occurred in two episodes. The first round was likely produced by the landslides triggered simultaneously by the initial earthquake doublet. The largest aftershock, which occurred 14 h after the doublet with a strike-slip mechanism, may have caused the landslides near the head of Kaoping Canyon and possibly the second-round tsunami.

What was the source of the nonseismic tsunami that occurred in Toyama Bay during the 2024 Noto Peninsula earthquake

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 role of heterogeneous stress in earthquake cycle models of the Hikurangi-Kermadec subduction zone

Summary Seismic and tsunami hazard modelling and preparedness are challenged by uncertainties in the earthquake source process. Important parameters such as the recurrence interval of earthquakes of a given magnitude at a particular location, the probability of multi-fault rupture, earthquake clustering, rupture directivity and slip distribution are often poorly constrained. Physics-based earthquake simulators, such as RSQSim, offer a means of probing uncertainties in these parameters by generating long-term catalogues of earthquake ruptures on a system of known faults. The fault initial stress state in these simulations is typically prescribed as a single uniform value, which can promote characteristic earthquake behaviours and reduce variability in modelled events. Here, we test the role of spatial heterogeneity in the distribution of the initial stresses and frictional properties on earthquake cycle simulations. We focus on the Hikurangi-Kermadec subduction zone, which may produce Mw > 9.0 earthquakes and likely poses a major hazard and risk to Aotearoa New Zealand. We explore RSQSim simulations of Hikurangi-Kermadec subduction earthquake cycles in which we vary the rate and state coefficients (a and b). The results are compared with the magnitude-frequency distribution (MFD) of the instrumental earthquake catalogue and with empirical slip scaling laws from global earthquakes. Our results suggest stress heterogeneity produces more realistic and less characteristic synthetic catalogues, making them particularly well suited for hazard and risk assessment. We further find that the initial stress effects are dominated by the initial effective normal stresses, since the normal stresses evolve more slowly than the shear stresses. A heterogeneous stress model with a constant pore-fluid pressure ratio and a constant state coefficient (b) of 0.003 produces the best fit to MFDs and empirical scaling laws, while the model with variable frictional properties produces the best fit to earthquake depth distribution and empirical scaling laws. This model is our preferred initial stress state and frictional property settings for earthquake modelling of the Hikurangi-Kermadec subduction interface. Introducing heterogeneity of other parameters within RSQSim (e.g. friction coefficient, reference slip rate, characteristic distance, initial state variable, etc) could further improve the applicability of the synthetic earthquake catalogues to seismic hazard problems and form the focus of future research.

Dataset of Post-Event Survey of the 2024 Noto Peninsula Earthquake Tsunami in Japan

An earthquake with a moment magnitude of 7.5 (Mw) struck the northern Noto Peninsula, Ishikawa Prefecture, Japan, at 16:10 local time on January 1, 2024. This earthquake triggered a tsunami that propagated along the coastline of Ishikawa, Toyama, and Niigata Prefectures facing the Sea of Japan and significantly damaged coastal communities and infrastructure. Approximately 70 researchers from 23 universities or other institutes throughout Japan formed a joint research group to conduct a post-tsunami survey along a 340 km stretch of the coast. Based on the watermarks and traces of the tsunami, the inundation and run-up heights were surveyed using total stations, automatic optical levels, laser range finders, and a real-time kinematic (RTK) Global Navigation Satellite System (GNSS). The tidal correction was adjusted using astronomical tidal tables. In total, 303 survey records have been compiled, generating the NP2024TS (Noto Peninsula 2024 Tsunami Survey) dataset. This dataset provides comprehensive information on the inundation and run-up heights of the tsunami, which is useful for understanding tsunami characteristics and validating numerical tsunami models.

Connecting Soft and Hard: An Integrating Role of Systems Dynamics in Tsunami Modeling and Simulation

Connecting Soft and Hard: An Integrating Role of Systems Dynamics in Tsunami Modeling and Simulation

Numerical Modelling of the Potential Hazard Due to Future Flores Back Arc Thrust Earthquake Generated Tsunami

Abstract Indonesia is situated at the conjunction of four major plates: Eurasia, India-Australia, the Pacific, and the Philippine Sea. Therefore, Indonesia is exposed to a considerable threat from natural hazards every day. Tectonic-related marine geohazards, particularly earthquakes-generated tsunamis periodically affect Indonesia, causing great loss of life and extensive damage to property and infrastructure in coastal areas. Many studies on tsunami modeling have been addressed in western Indonesia. In eastern Indonesia tsunamis, however, are even more frequent in occurrence and may be more hazardous, there is a lack of study and less attention. The Flores Back Arc Thrust (FBAT) is an active fault that lies on the sea floor of the Flores Sea in the north of Flores Island, extending from north of Bali to the east that may be connected to the Wetar thrust at the north of Wetar Island in the western Banda Sea. The FBAT is a source of seismicity in this area. From 1900 to 2022, there were 79 earthquakes with a magnitude of more than 6.0 Mw, and 11 of them generated tsunamis, and the most devastating one was the 1992 Flores earthquake tsunami. This study presents an estimated FBAT-induced future earthquake-generated tsunami runup based on numerical modeling.

High-resolution tsunami hazard assessment for the Guangdong-Hong Kong-Macao Greater Bay Area based on a non-hydrostatic tsunami model

High-resolution tsunami hazard assessment for the Guangdong-Hong Kong-Macao Greater Bay Area based on a non-hydrostatic tsunami model

Tsunami model of the 2021 Flores earthquake and its impact on Labuan Bajo, East Nusa Tenggara

Abstract The Flores earthquake on December 14, 2021, was recorded to cause a weak tsunami in East Nusa Tenggara. The epicenter was in the Flores Sea within 10 km of the hypocenter that triggered M 7.3 and impacted some coastline regions of East Nusa Tenggara, including Labuan Bajo. This study aimed to hindcast this phenomenon and mitigate the coastline region by applying the forecasting scenarios related to the amplification of the earthquake magnitudes and type of the sub-bottom displacements. The TUNAMI Software has been selected to illustrate tsunami wave propagation and inundation. The elevation data for the inputting model used BATNAS-DEMNAS National, while the rest of the parameters were applied using the two scenarios and the best guess. Based on the model results, it can be concluded that the source characteristics and the magnitudes played an essential role in inundating the coastal region in Labuan Bajo, West Manggarai Regency, East Nusa Tenggara.

Modern outlook on the source of the 551 AD tsunamigenic earthquake that struck the Phoenician (Lebanon) coast

On July 9th, 551 AD, a strong earthquake followed by a noticeable tsunami and another destructive shock hit the littoral zone of Phoenicia, currently Lebanon. The sequence of events was associated with active faults in the region, but the source able to explain both seismic and tsunami effects is still a matter of open debate. This article contributes to unlocking this enigma by providing a modern analysis of the historical accounts of macroseismic effects, earthquake environmental and tsunami effects, and archaeoseismic findings. Here, we conduct seismotectonic research, evaluate the intensities of all the associated effects, and perform coseismic deformation and numerical tsunami modeling to infer the most likely source. Our results suggest that either the thrust system noted as Mount Lebanon Thrust underlying Lebanon and crops out at the seabed offshore of the coast or the intermittent transpressive Tripoli-Batroun-Jounieh-Damour fault zone along the Lebanese coast are the best candidate sources for the 551 AD earthquakes and tsunami. Both of these sources allow us to better explain the macroseismic, morphological and tsunamigenic effects. Remarkably, the notable uplift of the coastal, marine-cut terraces along the Lebanese littoral zone is well reproduced by the coseismic uplift associated with these sources, thus also clarifying the considerable drawback of the sea and limited inundation reported by the historical accounts.

Testing Megathrust Rupture Models Using Tsunami Deposits

AbstractThe 26 January 1700 CE Cascadia subduction zone earthquake ruptured much of the plate boundary and generated a tsunami that deposited sand in coastal marshes from northern California to Vancouver Island. Although the depositional record of tsunami inundation is extensive in some of these marshes, few sites have been investigated in enough detail to map the inland extent of sand deposition and depict variability in tsunami deposit thickness and grain size. We collected 129 cores in marshes of the Salmon River estuary in Oregon and reanalyzed 114 core logs from a 1987–88 study that mapped the inland extent of circa 1700 CE sandy tsunami deposits. The ca. 1700 CE tsunami deposit in the Salmon River estuary is easily recognized in cores ≤1 m deep in which a buried marsh peat is overlain by a well sorted sand bed with a sharp lower contact that thins and fines inland. We use tsunami deposit data and models of sandy tsunami sediment transport (using Delft3D‐FLOW) to test 15 rupture models that could represent a ca. 1700 CE earthquake. At least 12–16 m of slip offshore of the Salmon River, which results in 0.8–1.0 m of coastal coseismic subsidence, is required to match the ca. 1700 CE sand deposit's inland extent, which is consistent with models of heterogeneous megathrust slip in ca. 1700 CE. Our methods of detailed tsunami deposit mapping, combined with sediment transport modeling, can be used to test models of megathrust ruptures and their tsunamis to potentially improve earthquake and tsunami hazard assessments.

Scenario-based tsunami hazard assessment for Northeastern Adriatic coasts

Significant tsunamis in the Northern Adriatic are rare, and only a few historical events have been reported in the literature, with sources mostly located along central and southern parts of the Adriatic coasts. Recently, a tsunami alert system has been established for the whole Mediterranean area; however, a detailed description of the potential impact of tsunami waves on coastal areas is still missing for several sites. This study aims to model the hazard associated with possible tsunamis generated by offshore earthquakes, with the purpose of contributing to tsunami risk assessment for selected urban areas along the Northeastern Adriatic coasts. Tsunami modelling is performed by the NAMI DANCE software, which allows accounting for seismic source properties, variable bathymetry, and nonlinear effects in wave propagation. Hazard scenarios at the shoreline are developed for the coastal areas of Northeastern Italy and at selected cities (namely, Trieste, Monfalcone, Lignano and Grado). An extensive set of potential tsunamigenic sources of tectonic origin located in three distance ranges (namely at Adriatic-wide, regional and local scales) are considered for the modelling. Sources are defined according to available literature, which includes catalogues of historical tsunamis and existing active faults databases. Accordingly, a set of tsunami-related parameters and maps are obtained (e.g. maximum run-up, arrival times, synthetic mareograms) that are relevant to planning mitigation actions at the selected sites.

The 2020 Mw 7.0 Samos (Eastern Aegean Sea) Earthquake: joint source inversion of multitype data, and tsunami modelling

SUMMARY We present a kinematic slip model and a simulation of the ensuing tsunami for the 2020 Mw 7.0 Néon Karlovásion (Samos, Eastern Aegean Sea) earthquake, generated from a joint inversion of high-rate GNSS, strong ground motion and InSAR data. From the inversion, we find that the source time function has a total duration of ∼20 s with three peaks at ∼4, 7.5 and 15 s corresponding to the development of three asperities. Most of the slip occurs at the west of the hypocentre and ends at the northwest downdip edge. The peak slip is ∼3.3 m, and the inverted rake angles indicate predominantly normal faulting motion. Compared with previous studies, these slip patterns have essentially similar asperity location, rupture dimension and anticorrelation with aftershocks. Consistent with our study, most published papers show the source duration of ∼20 s with three episodes of increased moment releases. For the ensuing tsunami, the eight available gauge records indicate that the tsunami waves last ∼18–30 hr depending on location, and the response period of tsunami is ∼10–35 min. The initial waves in the observed records and synthetic simulations show good agreement, which indirectly validates the performance of the inverted slip model. However, the synthetic waveforms struggle to generate long-duration tsunami behaviour in simulations. Our tests suggest that the resolution of the bathymetry may be a potential factor affecting the simulated tsunami duration and amplitude. It should be noted that the maximum wave height in the records may occur after the decay of synthetic wave amplitudes. This implies that the inability to model long-duration tsunamis could result in underestimation in future tsunami hazard assessments.

Study of tsunami source as preparation for tsunami modeling in Sulawesi

The Sulawesi region is prone to earthquakes due to the existence of a Subduction Zone which can generate a tsunami so that tsunami modeling is important as a tsunami mitigation effort in the future. The purpose of this research is to study the maximum earthquake potential in the Sulawesi Subduction Zone and to model the tsunami source with a multi-deformation scheme. The research method is a literature study using the 2017 National Earthquake Center book, tsunami modeling using an earthquake scenario with a magnitude of 8.5 Mw, a depth 20 Km, fault dimension modeling using global mapper software based on the Scaling law, fault dimensions with a length of the fault area and a width of the fault area, the earthquake parameters in the study consist of magnitude, epicentre depth, dip, slip, fault area length, the width of the fracture area and the dislocations. Tsunami source modeling uses the multi-fault. The results of this study are the maximum potential for an earthquake of around 8.5 Mw, the shape of the earthquake deformation and parameters as well as the tsunami source model that describes the sea level conditions experiencing an increase of 5,7 meters and for the decrease in sea level reaching -5.9 meters.

Tsunami Simulation in Paseban Beach Using Nesting Method on Delft3D Modeling

Paseban Beach is an area that has the potential for a tsunami hazard. In analyzing the tsunami hazard, accurate data and methods are essential. Therefore, this study aims to conduct a tsunami hazard analysis using the nesting method to obtain precise modeling results. This study utilizes the Delftdashboard and Delft3D-Flow programs. The modeling of the 1994 Banyuwangi tsunami results show that the validation stage has an accuracy of 7.94%, which means it is very accurate. The tsunami modeling using the 8.7 Mw megathrust earthquake showed the tsunami wave height in Paseban Beach reached 10,25 meters with 46 minutes arrival time. The length of the tsunami inundation was measured to be 2.96 km, with a run-up height of 2.98 meters.