Cornell Multi-grid Coupled Tsunami Research Articles

NUMERICAL MODELING OF THE 1998 PAPUA NEW GUINEA TSUNAMI USING THE COMCOT

The Papua New Guinea tsunami of 1998 is a unique phenomenon because the source of the tsunami propagation has been speculated. There was a 7.1-magnitude earthquake on July 17, 1998, at 18:49 WIT before the tsunami hit the Aitape area. However, previous studies have shown that the leading cause of the tsunami was not the earthquake but a submarine landslide. One of the steps to simulating the event is to do tsunami modeling. A tsunami propagation simulation will be conducted using Cornell Multi-grid Coupled Tsunami (COMCOT). This simulation was carried out with three scenarios to see which had the most significant effect on the tsunami event. The first scenario uses a tsunami source from a 7.1 magnitude earthquake, the following scenario is carried out using avalanche parameters, and the last scenario is a scenario with a combined source of earthquake and avalanche. The results of this study indicate that underwater landslides are the source of a tsunami similar to the original event.

Damage Spectra of SDOF Structures Under Tsunami Actions Considering the Nonlinear Dynamic Analysis Method

This paper studies the damage spectra of single-degree-of-freedom (SDOF) systems for tsunami loading. The 2011 Tohoku tsunami wave traces are computed and obtained by adopting the Cornell Multi-grid Coupled Tsunami (COMCOT) model and are further verified by the Tohoku Tsunami Joint Survey (TTJS) data. The tsunami response analyses of SDOF systems are conducted taking into account the dynamic analysis method. The classical ductility damage is considered as the damage performance. The damage spectra are computed for five force reduction factors and 791 tsunami loadings. The effects of inundation depths, hysteretic model, post-yield stiffness ratio, [Formula: see text], viscous damping ratio, [Formula: see text], are explored and interpreted scientifically and statistically. The results demonstrate that the effect of the hysteretic model, force reduction factor, R, post-yield stiffness ratio, [Formula: see text], viscous damping ratio, [Formula: see text], on the damage of the structure is evident. Comparison with the static method and influence analysis of structural damping indicate the necessity for the application of the dynamic method. A simplified predictive formulation is developed for the evaluation of structural damage for tsunami loadings.

Assessing the potential tsunami source of the Manila trench at the Bengkayang nuclear power plant site in Kalimantan using topographical details

Tsunamis pose a significant threat to the construction of Nuclear Power Plants. Therefore, it is necessary to carry out a comprehensive study regarding the potential threat of tsunamis and mitigation measures using detailed data at prospective locations. This assessment is a prerequisite for effective environmental impact planning and analysis. To determine the suitability of a prospective location, careful consideration of natural factors, including earthquakes as triggers for tsunamis, is essential. The main objective of this tsunami research is to assess the level of safety of potential locations against tsunami hazards and develop appropriate mitigation strategies. This research uses the Cornell Multigrid Coupled Tsunami (COMCOT) tsunami modeling technique. This modeling approach utilizes topographic and bathymetric data obtained through extensive field surveys. In addition, this research aims to determine the maximum tsunami height in the inundation area and identify potential tsunami hazards arising from various scenarios related to the active tectonic potential of the Philippine Manila Trench. The Bengkayang Gosong Beach area and West Kalimantan are among the candidate locations that may be affected with the estimated tsunami height being between 0.48 meters and 0.62 meters. The tsunami arrival time was between 9 hours 10 minutes to 9 hours 24 minutes. These findings play an important role in conducting comprehensive risk assessments for nuclear power plant development, ensuring that necessary steps are taken to reduce potential hazards associated with tsunamis.

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

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

Tsunami fragility based characterisation of mosques as alternatives tsunami evacuation buildings: Reconstructing evidence from the 2004 Indian ocean tsunami

Buildings located in coastal areas can also function as protection or shelter during a tsunami wave event. High buildings on the coast such as mosques can be used as vertical evacuation buildings when a tsunami occurs. During the 2004 Indian Ocean Tsunami (IOT), there were many people evacuated and saved at mosques. The community in this region evacuated themselves to some mosques during a tsunami evacuation order on April 11, 2012. However, there is no study has been conducted to prove the fragility of mosques against tsunamis and how the mosques can function as alternative tsunami evacuation buildings. This study is aimed at reconstructing evidence of the impacts of tsunamis on mosques and at assessing the opportunities to use mosques as alternative evacuation buildings. The research was conducted in two modes: (1) a series of numerical modelling were performed to reconstruct tsunami flow depths based on the 2004 Indian Ocean Tsunami (IOT), and (2) impacts of tsunami on mosques were collected based on survivor's eyewitness accounts or photos were taken immediately after the event. The impacts were later used to compose a set of tsunami fragility curves to see the influence of flow depth on the level of mosque damage. Field surveys were at four districts that were severely affected by the 2004 IOT, namely Banda Aceh, Aceh Jaya, West Aceh, and Aceh Besar. Tsunami wave simulations were performed using the Cornell Multigrid Coupled Tsunami Model (COMCOT) to obtain flow depths at mosque locations. Validations of the numerical simulation results were done using secondary flow depth data reported previously. A total of 210 mosque buildings were assessed at the study sites, where 98 % of them were constructed using reinforced concrete with varying building heights ranging from 5 to 11 m (from floor to ceiling). The probability of absolute damage was caused when flow depths exceeded 10 m. The mosque buildings has a lower probability of collapse compared the other building such as house and other building in general. At 3.0 m of flow depth, the mosque would only be totally destroyed by around 12 %. The lower damage probability for mosque buildings can be attributed to mosques being constructed with stronger structures than typical residential buildings.

Connecting community’s perspectives on tsunami risk to anticipated future tsunamis: a reflection from a progress of tsunami preparedness from a coastal community in Aceh-Indonesia after 19 years of the 2004 Indian Ocean Tsunami

This paper reflects on the progress of tsunami preparedness in a coastal community in Aceh, Indonesia, nearly two decades after the catastrophic 2004 Indian Ocean Tsunami. The research employs a comprehensive approach to thoroughly evaluate and comprehend the community’s preparedness, its correlation with local perceptions of tsunami risk, and delves into the prevalence of tsunamis in the area, with a specific emphasis on the significant impact of the 2004 Indian Ocean Tsunami on the coastal community of Aceh. To investigate the community’s readiness and the potential impacts of tsunamis at the study site, tsunami simulations were performed using the shallow water equation within the COMCOT (Cornell Multi-grid Coupled Tsunami) model. These simulations assessed run-up and inundation scenarios, thereby providing justification for the potential tsunami impact in the area. Modelling the scenario of tsunami in the region is important to measure the potential impact and estimation time for community to prepare the evacuation plan. In addition to the numerical modeling, a mixed-method approach was employed, involving the distribution of questionnaires and conducting in-depth interviews with 150 respondents directly on-site. These assessments yielded valuable insights into community perspectives on tsunami risk and their preparedness measures. The findings contribute to the development of effective strategies for disaster management by integrating local knowledge, experiences, and socialization programs. The study emphasizes the significance of ongoing endeavors to enhance community preparedness and mitigate the consequences of tsunamis.

Assessing probability of building damages due to tsunami hazards coupled with characteristics of buildings in Banda Aceh, Indonesia: A way to increase understanding of tsunami risks

Knowing the potential number of buildings that could be damaged by a future tsunami is important in understanding tsunami risk. There is a limited number of studies that combine the tsunami inundation area that is generated based on probabilistic tsunami hazard analysis and tsunami fragility curves. This study is aimed at providing information on probabilistic tsunami hazard for the city of Banda Aceh (Indonesia), whereby the results could possibly be integrated into tsunami risk reduction in the city. A series of numerical simulations were performed using the Cornell Multi-Grid Coupled Tsunami Model (COMCOT). Tsunami sources were taken from rupture areas generated by a set of earthquakes emanating from the Aceh-Andaman Megathrust segment. Later, tsunami inundation areas that were produced from numerical simulations were used in a probabilistic hazard analysis. This research produced three sets of tsunami inundation maps for 250-, 500-, and 1000-year return event periods. Hazard curves were produced based on 230,000 grids. Field surveys were performed in order to assess over 82,000 building units in Banda Aceh, and classified them into six types of buildings, in accordance with HAZUS (Hazards United States). Based on two sets data of buildings in Banda Aceh (measured in 2017 and 2021), there has been an increased number of buildings in the city by around 31%. Most of the new buildings were identified as houses. A set of tsunami fragility curves was used to estimate the damage ratio of each of the buildings. It was found that around 10.5% of the buildings (8708 units of buildings) would likely be totally demolished (swept away), should a 1000-year return period tsunami occur. Inundation maps produced for the 1000-year return period tsunami found in this study portray a similar situation to that of the 2004 Indian Ocean tsunami.

Fragility based characterization of alternative tsunami evacuation buildings in Banda Aceh, Indonesia

Providing sufficient structures suitable for vertical evacuation from tsunamis is critically important for a tsunami-prone city like Banda Aceh, the city most severely affected by the 2004 Indian Ocean tsunami. However, lack of sufficient financial capacity along with difficulties to find affordable land to be acquired have prevented some tsunami-prone cities to do so. This research is aimed at investigating potential structures to serve as alternative tsunami vertical evacuation buildings. The research was performed by mapping modified Building Tsunami Vulnerability (BTV) based on numerical simulations and types of the buildings. In 2018, all 79,420 structures in Banda Aceh were surveyed and classified into five building categories. Numerical simulations were performed using the Cornell Multi Grid Coupled Tsunami Model (COMCOT). Five scenarios of earthquake-triggered tsunamis were incorporated in the simulations, namely magnitude 9.2 Mw, 9.0 Mw, 8.8 Mw, 8.6 Mw, and 8.4 Mw events. Results of this research revealed that some 96 to 134 buildings could be used as alternative tsunami vertical evacuation buildings. None of the surveyed buildings could be classified as very low BTV condition. The buildings were schools, hotels, an assembly hall, government offices, and houses. The capacity of the alternatives evacuation buildings to accommodate tsunami evacuees were later calculated. The alternative tsunami evacuation buildings are expected to facilitate about 4 times the present capacity of six official tsunami escape buildings in Banda Aceh, Indonesia.

Performance Evaluation of DualSPHysics and COMCOT Programs through Numerical Testing for Simulating Tsunami Propagation and Overtopping on Seawalls

A tsunami is a destructive wave that can cause massive damage to coastal infrastructure. One of the disaster mitigation measures that can be chosen is the construction of coastal protection infrastructure, such as a seawall. Seawalls play a crucial role in protecting coastal areas as they can reduce wave energy and minimize the impact of tsunami-induced damage. However, during the 2011 Japan tsunami, the seawall built in Taro city failed as it proved to be less effective in handling the tsunami waves. The research conducted aims to model the propagation and overtopping of tsunami waves on the seawall, initially carried out through physical laboratory experiments, and later transformed into numerical test models using the Smoothed Particle Hydrodynamics (SPH) method and the Cornell Multigrid Coupled Tsunami (COMCOT) model. In this study, the parameters being compared include wave height, wave propagation, and overtopping on the seawall under two scenarios : the run-up of solitary waves on a shore without a seawall and the overtopping condition with a seawall using the Solitary Wave generation type, following the experiments conducted by Huang et al en 2022. Several parameters in the laboratory case study should be considered to expand our understanding of the systematically discussed tsunami propagation and overtopping processes and evaluate the capabilities of the SPH and COMCOT models.

Estimating Impacts of Tsunami on Buildings around Ambon Bay of Indonesia

Ambon is a city situated inside a long bay in eastern part of Indonesia. The city has been stricken by a number of tsunamis in the past. The last tsunami event was generated by a submarine landslide inside the bay that hit two villages in the city in 1950. Despite the long story of tsunamis inside the Ambon city, no study has been conducted to estimate the impacts of future tsunamis on the growing coastal area of Ambon. This study was aimed at assessing the building vulnerability in Ambon due to projected impacts of future tsunamis. A numerical simulation was performed to generate tsunami inundation areas in the city using Cornell Multi Grid Coupled Tsunami Model (COMCOT) based on maximum fault area in the segment. A series of field works to classify the building types in the city were performed in May 2023 on around 70,000 units of buildings along the bay of Ambon. The classifications were done using Hazard United States (HAZUS) frameworks. Tsunami fragility curves were used to estimate the impacts of the tsunami based on flow depths obtained from the numerical simulations. Based on the surveys, this study found that buildings within 200 m from coastline of the bay could be in Damage State 4 (DS4) which is the most severe impacts of tsunamis on buildings.

Probabilistic Analysis of the Tsunami Disaster on the Vulnerability Level of Buildings in Painan City, West Sumatra based on the Earthquake Ratio with the Logic Tree Method

Indonesia is an archipelagic country stretching from Sabang to Merauke and is located at the convergence of the most complex and active tectonic plates in the world, namely Eurasia, Indo-Australia, and the Pacific. One of the regions with a high probability of earthquakes and high tsunamis is the island of Sumatra, which lies between the Eurasian and Indo-Australian plates. Painan city is located in West Sumatra Province, where it is surrounded by three megathrust zones: the Nias-Simeulue segment, Mentawai-Siberut segment, and Mentawai-Pagai segment. These three megathrust zones, namely Nias-Simeulue with an estimated earthquake magnitude of 8.7 Mw, Mentawai-Siberut with an earthquake magnitude of 8.9 Mw, and Mentawai-Pagai with an earthquake magnitude of 8.9 Mw, can potentially cause tsunamis that may reach Painan city. The aim of this study is to investigate the influence of seismic activity level variables and the ratio between large and small earthquakes on tsunami wave height using the logic tree method, assess the tsunami hazard potential using Probabilistic Tsunami Hazard Assessment (PTHA), and evaluate the vulnerability of existing buildings in Painan city. Tsunami simulations in this study were conducted using the Cornell Multigrid Coupled Tsunami (COMCOT) program, which applies the Shallow Water Equation (SWE). Additionally, the Building Tsunami Vulnerability (BTV) equation was used to calculate the vulnerability index of buildings based on their conditions and tsunami wave heights. The calculation of the BTV value for the tsunami height parameter was modified using fragility curves that depict the relationship between force and the probability of tsunami wave damage. From the simulation results, the tsunami height was obtained, which in turn determines the probability of tsunami hazard on buildings with return periods of 1000 and 4000 years. After the simulations, the Building Tsunami Vulnerability (BTV) calculation was performed to determine the vulnerability level of buildings to tsunamis.

Building Vulnerability Analysis Due to Tsunami by Using Probabilistic Tsunami Hazard Assessment (PTHA): A Case Study of Pelabuhan Ratu, Sukabumi

Cities that vulnerable to tsunamis, including the village of Pelabuhan Ratu on the southern coast of West Java, Indonesia, are in dire need of adequate vertical evacuation structures. However, constraints regarding to limited funding and difficulties in finding affordable land have hindered the implementation efforts of such structures in several cities. This research aims to analyze building vulnerability to tsunami disasters and identify buildings that can serve as alternative tsunami evacuation options based on Probabilistic Tsunami Hazard Analysis (PTHA) in Pelabuhan Ratu. The research methodology involves mapping the Modified Building Tsunami Vulnerability (BTV) and connecting the numerical simulation results with fragility curves assumed for the Pelabuhan Ratu area. The numerical simulations were conducted using the Cornell Multi-Grid Coupled Tsunami Model (COMCOT). Various tsunami scenarios triggered by earthquakes with different magnitudes ranging from 8.5 to 9.0, with intervals of 0.1, were considered in the numerical simulations. The research findings indicates high probability of maximum tsunami height reaching 14.85 meters in a return period of 10,000 years, and 51.77 meters in return period of 30,000 years. Based on these results, it was found that a three-story minimarket built with concrete could be used as an evacuation facility in a 10,000-year return period.

Simulation of Tsunami Inundation for the Island of Martinique to Nearby Large Earthquakes

ABSTRACT In this article, we estimate the tsunami hazard in Martinique due to tsunamis generated by earthquakes associated with the Lesser Antilles subduction zone. Using a deterministic approach based on reliable earthquake scenarios, we use high-resolution bathymetric and topographic data to model tsunami propagation and inundation with Cornell Multi-grid Coupled Tsunami model. An extreme earthquake subduction scenario of magnitude Mw 8.0 is tested, and a further realistic scenario of lower magnitude Mw 7.5, thus of different tsunami frequency content, is also processed to test the possible appearance of bay resonances. We find that the western coast of the island is relatively sheltered, because it represents a shadow area to diffraction, in particular, for the major city of Fort de France. Because of its very gentle slope, the eastern coast is prone to numerous floodings with meter scale wave amplitudes; most of the inundated zones consist of mangroves and geological depressions t are naturally regularly flooded by tides or storm surges. Hence such areas are often not exploited, the mangroves being let in their natural state, enhancing the protection of the surrounding communities. However, some strategic inhabited areas are subject to severe inundation. Finally, comparing our results with studies of the 1755 Lisbon transoceanic tsunami reveals a tsunami hazard close to our local Mw 7.5 scenario. It suggests the possibility to generalize our local tsunami hazard assessment in Martinique to other tsunami contexts and enlarge its validity. This issue is crucial for minimizing the efforts and increasing the efficiency of tsunami preparedness.

Historical tsunamis of Taiwan in the 18th century: the 1781 Jiateng Harbor flooding and 1782 tsunami event

Abstract. This research aims to study two historical tsunamis that occurred in Taiwan during the 18th century and to reconstruct the incidents. The 1781 Jiateng Harbor flooding, recorded by the Chinese historical document entitled “Taiwan Interview Catalogue” took place on the southwest coast of Taiwan. In contrast, the 1782 tsunami was documented in foreign languages, with uncertainties about the actual time. These two events seem to be close enough in time and location that, to some researchers, they are considered as the same event. Reasoning these historical events requires carefully examining the literature records and performing the scenarios that match the descriptions. The impact intensity analysis (IIA) is employed to locate possible regions of tsunami sources in order to reproduce the events. Numerical simulations based on the Cornell Multi-grid Coupled Tsunami Model (COMCOT) analyze the influence of different types of tsunamis generated by both submarine mass failures and seismic activities. Numerical results indicate that the source of the 1781 Jiateng Harbor flooding is located very possibly on the south-southwestern side of Taiwan. However, simulation results and historical records put the existence of the 1782 tsunami in doubt, and the possibility of storm surges could not be ruled out.

Investigating characteristics of tsunami hazards for west coast of Aceh Besar district, Indonesia

The seismic activities of a long section of the Sunda Plate revealed the vulnerability of the Indian Ocean to tsunami along the west coast of Sumatra, including on the west coast of Aceh Province. This megathrust caused the great tsunamigenic earthquake of 2004 and can be a possible candidate for rupture in the future and will affect or destroy everything, especially buildings along the coast. The west coast of Aceh Besar is one of the worst areas hit by tsunami waves and can cause tsunamis in the future. The objectives of this study are to determine the height, distance, and area of the tsunami inundation on the west coast of Aceh Besar District based on three earthquake magnitudes scenarios Mw 8.0, 8.5, and 9.2. The COMCOT (Cornell Multigrid Coupled Tsunami Model) tsunami model was used to obtain the height, area, and distance of the tsunami inundation. It was found that the largest tsunami inundation was caused by the tsunami generated by the magnitude Mw 9.2 earthquake. The maximum tsunami run up reached up to 20 meters with an inundation distance of 6 km from the coastline and a tsunami inundation area of 40 km2distributed along the west coast of Aceh Besar District.

Analysis of the tsunami amplification effect by resonance in Yeongil Bay

Predicting tsunami hazards based on the tsunami source, propagation, runup patterns is critical to protect humans and property. Potential tsunami zone, as well as the historical tsunamis in 1983 and 1993, can be a threat to the east coast of South Korea. The Korea Meteorological Administration established a tsunami forecast warning system to reduce damage from tsunamis, but it does not consider tsunami amplification in the bay due to resonance. In this study, the Numerical model, Cornell Multi-grid Coupled Tsunami model, was used to investigate natural frequency in the bay due to coastal geometry. The study area is Yeongill bay in Pohang, southeast of South Korea, because this area is a natural bay and includes three harbors where resonance significantly occurs. This study generated a Gaussian-shaped tsunami, propagated it into the Yeongill bay, and compared numerical modeling results with data from tide gauge located in Yeongill bay during several storms through spectral analysis. It was found that both energies of tsunamis and storms were amplified at the same frequencies, and maximum tsunami wave height was amplified about 3.12 times. The results in this study can contribute to quantifying the amplification of tsunami heights in the bay.

GIS Based Tsunami Risk Assessment

Tsunami is a coastal hazard which occur due to undersea earthquakes, Meteorite falls, volcanic eruptions or even nuclear weapon operations. The tsunami hazard which occurred in December 2004 was generated due to an undersea earthquake 400m west of northern Sumatra and it inundated coastal areas of Indonesia, Sri Lanka, Thailand and India. This hazard became one of the worst disasters in the history resulting in over thirty thousand fatalities and over seventy thousand house damage in Sri Lanka. This study is focused towards creation of GIS based Tsunami risk map for Galle city which was badly hit by the 2004 Tsunami. Tsunami vulnerability was assessed using weighted overlay spatial method with input parameters of population density, sex ratio, age ratio, disability ratio and damaged building ratio. Tsunami hazard map was developed based on tsunami inundation map which was published by Coastal research and design, costal conservation and resource management department with assistant from Disaster management centre using the Cornell Multigrid Coupled Tsunami Model (COMCOT). Vulnerable and hazard maps were analysed and incorporated to develop final risk map using GIS tool. Keywords GIS; Tsunami Inundation Map; Tsunami Risk Map; Vulnerability; Disaster

Coupling sea-level rise with tsunamis: Projected adverse impact of future tsunamis on Banda Aceh city, Indonesia

This research is aimed at investigating the impacts of sea-level rise (SLR) and tsunamis on Banda Aceh using several long-term scenarios based on the Sunda mega-thrust, the source of the 2004 Indian Ocean tsunami. Six earthquake magnitudes—Mw 8.2, 8.4, 8.6, 8.8, 9.0 and 9.15—were used to perform a number of numerical simulations using Cornell Multi-grid Coupled Tsunami model (COMCOT) with six simulation layers. The largest magnitude is from the earthquake that triggered the 2004 Indian Ocean tsunami. The sea level in the region rises at the rate of 7 mm/year. This research used the SLR rate to project the impacts of SLR and tsunamis for 50, 100, 150 and 200 years. The SLR rates were also combined with three variations of tides, namely at lowest-low water level (LLWL), mean sea level (MSL), and highest-high water level (HHWL). One hundred twenty tsunami scenarios that included two land-use cover periods—2004 Land Use and Land Cover (LULC) and the 2029 LULC—were simulated. The latter is stipulated in the long-term city planning of Banda Aceh is to be implemented at the end of 2029. This research found that the impact of the tsunamis triggered by 8.2–8.6 magnitude earthquakes could be doubled if they are coupled with impacts of SLR.

Analysis of tsunami hazard in the Southern Coast of West Java Province - Indonesia

The Southern Coast of West Java Province in the Java Islands is one of prone and exposed area to tsunami hazard. It has about 428 kilometers coastline length, covering 5 administrational regencies (i.e. Sukabumi, Cianjur, Garut, Tasikmalaya, and Pangandaran). It is a strategic area that support many economic activities including tourism, fisheries, electricity power plants, agricultures, markets as well as social factors such as coastal villages, schools and other public facilities. The existence of this strategic area is threatened by the potential for a tsunami disaster mainly from megathrust along the Southern Coast of Java Island. On 2006, a tsunami earthquake of M7.7 occurred off Pangandaran Regency with tsunami height of 5-8 meters and inundated about 500 meters along southern coast of West and Central Java Province. The tsunami caused more than 600 casualties and damage to buildings, public facilities and insfrastructure. Yet, the Indonesia National Earthquake Source and Hazard Map suggest a bigger threat of a plausible M8.7 – M9.2 megathrust earthquake off Java island. This research aims to analyze and map potential areas affected by the tsunami in the South Coast of West Java Province based on numerical modelling carried out with Cornell Multi-grid Coupled Tsunami Model (COMCOT) v1.7 based on the several megathrust earthquake scenarios in southern off West Java. The results of tsunami modelling show that the highest impact is generated in the Sunda Straits & West Java - Central Java Megathrust Scenarios with highest tsunami inundation and the fastest travel time occurred in Cianjur Regency with 26,7 meters height and estimated arrival time of tsunami wave approximately 10 minutes after the mainshock, while the farthest inundation distance is estimated in Sukabumi Regency about 5.8 kilometers from the coast due to existence of river.

Knowledge-Building Approach for Tsunami Impact Analysis Aided by Citizen Science

Large tsunami events are devastating even though the impacts are limited to coastal areas. Knowledge is the key to minimize the losses from natural disasters by more proactive and better preparation. Targeting on natural hazards mitigation in Asia, a collaboration among 10 Asian and 2 European countries based on deeper understanding approach has been conducted since 2015. Deeper understanding is to discover the physical mechanisms and drivers behind a hazard event. Innovative model and simulation facilities are developed correspondingly to achieve more accurate numerical simulations of the whole lifespan of the target event. Application framework composed by the knowledge, data, simulation facility, software tools and case studies is designed to provide advanced estimation of hazard risk and would be evolved progressively with more case studies and observation data. For tsunami, based on the COMCOT (COrnell Multi-grid Coupled Tsunami Model), the simulation portal (iCOMCOT) implementing parallelized tsunami wave propagation calculation over distributed cloud had been established. iCOMCOT system finished the simulation of whole lifecycle of the 2011 Great East Japan Earthquake Tsunami in one minute. In this regional collaboration, case studies on historical events and tsunami impact analysis were conducted. The goal is to capture the physical characteristics of tsunami as much as possible such as tsunami wave propagation, tsunami refraction, tsunami run-up on land, as well as their drivers and root causes. The whole processes of tsunami from its initiation to its impacts in selected locations then could be simulated accurately by iCOMCOT based on the scientific explorations and the revised models quantitatively. Sulawesi Tsunami (2018) case is presented to demonstrate the processes of deeper understanding approach and how to achieve the capacity building. At the same time, the ways to take advantages of citizen science are also explored. Citizen science model is valuable in supporting data collection such as data of run up height, inundation range, flow depth, disruption information, impact area, from publication, news report, and interviews of local people. According to experiences on case studies, suggestions to simplify and optimize the integration of citizen science model with deeper understanding approach to lower operation cost are provided.