scholarly journals Spatial Analysis on Tsunami Predictions in Pandeglang Regency

2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Della Ayu Lestari ◽  
Novi Sofia Fitriasari ◽  
Taufiq Ejaz Ahmad ◽  
Amien Rais ◽  
Dhea Rahma Azhari
Keyword(s):  
Maximum Height ◽  
Tsunami Height ◽  
Tsunami Inundation ◽  
National Board ◽  
Tsunami Hazards ◽  
Wave Heights ◽  
One Step ◽  
Krakatau Volcano ◽  
Inundation Height ◽  
Spatial Plan

Pandeglang Regency is an area that has the potentiel to be hit by tsunamis. The plate subduction paths of Indo-Australia and Anak Krakatau Volcano make Pandeglang Regency a region with a high tsunami potential. One step that can be taken to overcome and minimize losses is to do spatial planning to protect it against potential tsunami damage. This research aimed to evaluate the spatial area of Pandeglang Regency based on the identification of potential tsunami hazards.  The concept of modelling the tsunami inundation height developed by Berryman and based on Head Regulation No.4 of 2012 of the Indonesian National Board for Disaster Management has been used to identify potential tsunami hazards. The modelling was carried out by calculating the potential distribution of tsunami wave heights in coastal areas.  Three scenarios were used to estimate the distribution. The results showed that the first scenario predicted a maximum tsunami height   of 7.5 meters above sea level with the furthest tsunami inundation reaching 1,700.12 meters. Second scenario predicted maximum height of 15 meters, with the furthest tsunami inundation reaching 3,384.62 meters. Meanwhile, the last scenario was able to predict a height of 20 meters and showed the furthest tsunami inundation reaching 5.155,11 meters. These results proved that in all scenarios, the widest inundation would occur in Panimbang Regency. This is due to the relatively small variations in roughness and slope of the surface. The same condition also occurs in the last two scenarios, in which Sumur District was the area most ffected. Therefore, the spatial plan of Pandeglang Regency needs to be evaluated and the function of residential area changed to reduce and prevent large losses.

scholarly journals Field Survey of Tsunami Heights and Runups Following the 22 December 2018 Anak Krakatau Volcano Tsunami, Indonesia

2020 ◽  
Vol 177 (10) ◽  
pp. 4577-4595 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Purna Sulastya Putra ◽  
Septriono Hari Nugroho ◽  
Doud Ben Zubair Rashid
Keyword(s):  
Rare Event ◽  
Tsunami Height ◽  
Field Surveys ◽  
Tsunami Runup ◽  
Tsunami Risk ◽  
Western Shore ◽  
Wave Heights ◽  
One Year ◽  
Instrumental Records ◽  
Krakatau Volcano

Abstract The 22 December 2018 Anak Karakatau tsunami in Indonesia was a rare event in that few instrumental records existed of tsunamis generated by volcanic sources before this event. The tsunami, which left a death toll of 437, is of global importance as it provides opportunities to develop knowledge on generation, propagation and coastal effects of volcanic tsunamis. Here, we report results of field surveys along the coast of the Sunda Strait, Indonesia to study tsunami wave heights and coastal damage. We surveyed 29 locations and measured ranges of tsunami runup from 0.9 to 5.2 m, tsunami heights from 1.4 to 6.3 m, flow depths from 0.2 m to 3.0 m and inundation distances from 18 to 212 m. The largest tsunami heights and concentration of damage and fatalities occurred on the western shore of Java from Tanjung Lesung to Sumur. The largest cluster of fatalities occurred at Tanjung Lesung, where more than 50 people died while attending an outdoor music being held at the shoreline. The tsunami runup and tsunami height in Tanjung Lesung were 4.0 and 2.9–3.8 m, respectively. We believe this tragedy could have been avoided if the event organizers were more aware of the hazard posed by the Anak Krakatau volcano, as it had been actively erupting for several months prior to the tsunami, and simply moved the concert stage 100 m inland. Many of the locations surveyed demonstrated a similar pattern where the majority of casualties and destruction occurred within 100 m of the coast; in several locations, lives were saved where buildings were located at least this distance inland. The significant damage and numerous deaths which occurred in Sumur, despite the moderate tsunami height of 2.3–2.5 m, can be attributed to the extremely low-lying coastal land there. Flow depth in Sumur was 0.9–2.0 m. During our field surveys, nearly one year after the event, we noted that some of the damaged buildings were being rebuilt in the same locations just 10–30 m from the shoreline. We question this practice since the new buildings could be at the same tsunami risk as those damaged in the 2018 event.

Field surveys and numerical modeling of the December 2018 Anak Krakatau volcanic tsunami

2020 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Purna Sulastya Putra ◽  
Abdul Muhari ◽  
Septriono Hari Nugroho
Keyword(s):  
Numerical Modeling ◽  
Source Model ◽  
Tsunami Source ◽  
Tsunami Height ◽  
Tsunami Inundation ◽  
Field Surveys ◽  
Source Models ◽  
Krakatau Volcano ◽  
Source Dimension ◽  
Maximum Tsunami Height

<p>We report results of field surveys and numerical modeling of the tsunami generated by the Anak Krakatau volcano eruption on 22 December 2018. We conducted two sets of field surveys of the coastal areas destroyed by the Anak Krakatau tsunami in 26-30 December 2018 and 4-10 January 2020. Field surveys provided information about the maximum tsunami height as well as the most damaged area. The maximum tsunami height was up to 13 m. Most locations registered a wave height of 3-4 m. Tsunami inundation was limited to approximately 100 m. For modeling, we considered 12 source models and conducted numerical modeling. The scenarios have source dimensions of 1.5–4 km and initial tsunami amplitudes of 10–200 m. By comparing observed and simulated waveforms, we constrained the tsunami source dimension and initial amplitude in the ranges of 1.5–2.5 km and 100–150 m, respectively. The best source model involves potential energy of 7.14 × 10<sup>13</sup>–1.05 × 10<sup>14</sup> J which is equivalent to an earthquake of magnitude 6.0–6.1.</p>

scholarly journals Pandeglang regency spatial evaluation based on tsunami hazard potential

2020 ◽  
Vol 156 ◽  
pp. 04010
Author(s):  
Roihan Nauval Majid ◽  
Triarko Nurlambang
Keyword(s):  
Coastal Area ◽  
Tsunami Hazard ◽  
Residential Land ◽  
Gis Modeling ◽  
Tsunami Hazards ◽  
Tsunami Disaster ◽  
Open Land ◽  
Wave Heights ◽  
Spatial Plan ◽  
Plate Subduction

The coastal area of Pandeglang Regency is one area that has the potential to be affected by the tsunami. The existence of the Krakatau Anak Volcano and plate subduction paths in the Sunda Strait cause Pandeglang Regency to become one of the regions that has a tsunami potential. One of the steps to anticipate the tsunami disaster is to do spatial planning that has considered the potential tsunami hazard. The purpose of this research is to evaluate the spatial area of Pandeglang Regency based on the identification of potential tsunami hazards. The identification of potential tsunami hazards is done by modeling the potential distribution of tsunami wave heights in coastal areas using GIS modeling. The results of the identification of potential tsunami hazards on the coast of Pandeglang Regency showed that an area of 194.15 hectares of residential land and the location of existing activities had the potential to be affected by the tsunami. The total area of the coastal area of Pandeglang Regency which was potentially affected by the tsunami hazard reached 1483.26 hectares. The results of a review of the Pandeglang Regency's spatial plan showed that 488.22 hectares of land were found in the planned residential spatial patterns that were potentially affected by the tsunami. Therefore, the regional spatial plan of Pandeglang Regency in the study area needs to be evaluated by changing the function of residential land that has the potential to be affected by the tsunami hazard to the border of the beach or other open land.

scholarly journals Numerical modelling of historical landslide-generated tsunamis in the French Lesser Antilles

2010 ◽  
Vol 10 (6) ◽  
pp. 1281-1292 ◽  
Author(s):  
B. Poisson ◽  
R. Pedreros
Keyword(s):  
Near Field ◽  
Pyroclastic Flows ◽  
Lesser Antilles ◽  
Published Data ◽  
Tsunami Height ◽  
Tsunami Modelling ◽  
Field Effects ◽  
Wave Heights ◽  
Unique Source ◽  
Height Data

Abstract. Two historical landslide-induced tsunamis that reached the coasts of the French Lesser Antilles are studied. First, the Martinique coast was hit by a tsunami down the western flank of Montagne Pelée at the beginning of the big eruption of May 1902. More recently, the northeastern coast of Guadeloupe was affected by a tsunami that had been generated around Montserrat by pyroclastic flows entering the sea, during the July 2003 eruption of the Soufrière Hills volcano. We use a modified version of the GEOWAVE model to compute numerical simulations of both events. Two source hypotheses are considered for each tsunami. The comparison of the simulation results with reported tsunami height data helps to discriminate between the tested source decriptions. In the Martinique case, we obtain a better fit to data when considering three successive lahars entering the sea, as a simplified single source leads to an overstimation of the tsunami wave heights at the coast. In the Montserrat case, the best model uses a unique source which volume corresponds to published data concerning the peak volume flow. These findings emphasize the importance of an accurate description of the relevant volume as well as the timing sequence of the source event in landslide-generated tsunami modelling. They also show that considering far-field effects in addition to near-field effects may significantly improve tsunami modelling.

Simulation of Tsunami Inundation in Central Peru from Future Megathrust Earthquake Scenarios

2014 ◽  
Vol 9 (6) ◽  
pp. 961-967 ◽  
Author(s):  
Erick Mas ◽  
◽  
Bruno Adriano ◽  
Nelson Pulido ◽  
Cesar Jimenez ◽  
...  
Keyword(s):  
Hazard Mapping ◽  
Slip Model ◽  
Tsunami Height ◽  
Ground Acceleration ◽  
Tsunami Inundation ◽  
Tsunami Simulation ◽  
Earthquake Scenarios ◽  
Spatially Correlated ◽  
Megathrust Earthquakes ◽  
Interseismic Coupling

We estimated, from twelve scenarios of potential megathrust earthquakes, the tsunami impact on the Lima-Callao region in Central Peru. In addition, we conducted hazard mapping using the local envelope of the maximum inundation simulated in these scenarios. The deterministic approach is supported by the decades of geodetic measurements in this area that characterize the interseismic strain build up since historical megathrust earthquakes. The earthquake scenarios for simulation proposed in [1] introduce spatially correlated short-wavelength slip heterogeneities to a first slip model in [2] calculated from the interseismic coupling (ISC) distribution in Central Peru. The ISC was derived from GPS monitoring data as well as from historical earthquake information. The results of strong ground motion simulations in [1] reported that the slip scenario with the deepest average peak values along the strike (Mw= 8.86) generates the largest PGA in the Lima-Callao area. In this study, we found from tsunami simulation results that the slip model with the largest peak slip at a shallow depth (Mw= 8.87) yielded the highest tsunami inundation. Such differences in maximum scenarios for peak ground acceleration and tsunami height reveal the importance of a comprehensive assessment of earthquake and tsunami hazards in order to provide plausible worstcase scenarios for disaster risk management and education.

scholarly journals Frequency dispersion amplifies tsunamis caused by outer-rise normal faults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshitaka Baba ◽  
Naotaka Chikasada ◽  
Kentaro Imai ◽  
Yuichiro Tanioka ◽  
Shuichi Kodaira
Keyword(s):  
Water Waves ◽  
Frequency Dispersion ◽  
Japan Trench ◽  
Normal Faults ◽  
Ocean Bottom ◽  
Hazard Maps ◽  
Tsunami Height ◽  
Tsunami Inundation ◽  
Outer Rise ◽  
Spatial Dimensions

AbstractAlthough tsunamis are dispersive water waves, hazard maps for earthquake-generated tsunamis neglect dispersive effects because the spatial dimensions of tsunamis are much greater than the water depth, and dispersive effects are generally small. Furthermore, calculations that include non-dispersive effects tend to predict higher tsunamis than ones that include dispersive effects. Although non-dispersive models may overestimate the tsunami height, this conservative approach is acceptable in disaster management, where the goal is to save lives and protect property. However, we demonstrate that offshore frequency dispersion amplifies tsunamis caused by outer-rise earthquakes, which displace the ocean bottom downward in a narrow area, generating a dispersive short-wavelength and pulling-dominant (water withdrawn) tsunami. We compared observational evidence and calculations of tsunami for a 1933 Mw 8.3 outer-rise earthquake along the Japan Trench. Dispersive (Boussinesq) calculations predicted significant frequency dispersion in the 1933 tsunami. The dispersive tsunami deformation offshore produced tsunami inundation heights that were about 10% larger than those predicted by non-dispersive (long-wave) calculations. The dispersive tsunami calculations simulated the observed tsunami inundation heights better than did the non-dispersive tsunami calculations. Contrary to conventional practice, we conclude that dispersive calculations are essential when preparing deterministic hazard maps for outer-rise tsunamis.

scholarly journals Effects of Tides on Maximum Tsunami Wave Heights: Probability Distributions*

2007 ◽  
Vol 24 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Harold O. Mofjeld ◽  
Frank I. González ◽  
Vasily V. Titov ◽  
Angie J. Venturato ◽  
Jean C. Newman
Keyword(s):  
Probability Distributions ◽  
High Water ◽  
Tidal Range ◽  
Maximum Height ◽  
Gaussian Form ◽  
Arrival Times ◽  
Probabilistic Mapping ◽  
Wave Heights ◽  
The Difference ◽  
Tsunami Amplitude

Abstract A theoretical study was carried out to understand how the probability distribution for maximum wave heights (ηm) during tsunamis depends on the initial tsunami amplitude (A) and the tides. It was assumed that the total wave height is the linear sum of the tides and tsunami time series in which the latter is decaying exponentially in amplitude with an e-folding time of 2.0 days, based on the behavior of observed Pacific-wide tsunamis. Direct computations were made to determine the statistics of maximum height for a suite of different arrival times and initial tsunami amplitudes. Using predicted tides for 1992 when the lunar nodal f factors were near unity during the present National Tidal Datum Epoch 1983–2001, the results show that when A is small compared with the tidal range the probability density function (PDF) of the difference ηm − A is closely confined in height near mean higher high water (MHHW). The ηm − A PDF spreads in height and its mean height ηo − A decreases, approaching the PDF of the tides and MSL, respectively, when A becomes large compared with the tidal range. A Gaussian form is found to be a close approximation to the ηm − A PDF over much of the amplitude range; associated parameters for 30 coastal stations along the U.S. West Coast, Alaska, and Hawaii are given in the paper. The formula should prove useful in probabilistic mapping of coastal tsunami flooding.

Field Survey of the 2018 Anak Krakatau Tsunami on the Islands in the Sunda Strait

2020 ◽  
Author(s):  
Hermann M. Fritz ◽  
Tubagus Solihuddin ◽  
Costas E. Synolakis ◽  
Gegar S. Prasetya ◽  
Jose C. Borrero ◽  
...  
Keyword(s):  
Tsunami Source ◽  
Flow Depth ◽  
Community Based Education ◽  
Tsunami Hazards ◽  
Survey Team ◽  
Tsunami Runup ◽  
Awareness Programs ◽  
Education And Awareness ◽  
Krakatau Volcano ◽  
Steep Slopes

<p>On December 22, 2018, an eruption and partial collapse of the Anak Krakatau volcano generated a tsunami in the Sunda Strait. The tsunami caused catastrophic damage and more than 400 deaths in coastal regions of the Sunda Strait in Lampung (Sumatra) and Banten (Java). An international tsunami survey team (ITST) was deployed 6 weeks after the event to document flow depths, runup heights, inundation distances, sediment deposition, impact on the natural environment and infrastructure. The 4 to 9 February 2019 ITST focused on islands in the Sunda Strait: Rakata, Panjang, Sertung, Sebesi and Panaitan. The survey team logged more than 500 km by small boat. The collected survey data includes almost 100 tsunami runup and flow depth measurements. The tsunami impact peaked along steep slopes facing Anak Krakatau with an 85 m runup on Rakata and an 83 m runup on Sertung. The extreme runup heights were within less than 5 km of Anak Krakatau. Flow depth reached more than 11 m above ground on Sertung where a boat landing was possible and trees remained standing. On Sebesi Island located 15 km northeast of the source tsunami runup heights remained below 10 m. In contrast, tsunami heights exceeding 10 m were observed in the Ujung Kulon National Park located 50 km southwest of Anak Krakatau. The runup distributions on the islands encircling Anak Krakatau highlight the directivity of the tsunami source with the Anak Krakatau collapse towards the southwest. Inundation and damage were mostly limited to within 400 m of the shoreline given the relatively short wavelengths of volcanic tsunamis. Significant variation in tsunami impact was observed along shorelines of the Sunda Strait with tsunami heights rapidly decreasing with distance from the point source. Field observations, drone videos, and satellite imagery are presented. The team interviewed numerous eyewitnesses based on established protocol and educated residents about tsunami hazards. The tsunami caught the locals off guard despite the history and a six-month long eruptive activity in the lead up. Community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis. The 500 m initial height difference between the 1883 Krakatau and 2018 Anak Krakatau collapses provides a perspective on these two tsunamis. Remaining and future tsunami hazards will be affected by volcanic edifice regrowth.</p>

scholarly journals Combined hazard of typhoon-generated meteorological tsunamis and storm surges along the coast of Japan

2020 ◽  
Author(s):  
Mohammad Heidarzadeh ◽  
Alexander B. Rabinovich
Keyword(s):  
Sea Level ◽  
Low Frequency ◽  
Storm Surges ◽  
Statistical Characteristics ◽  
Maximum Height ◽  
Sea Levels ◽  
Relative Contribution ◽  
The Pacific ◽  
Wave Heights ◽  
Pacific Coast Of Japan

AbstractTwo hazardous typhoons, Lionrock (August 2016) and Jebi (September 2018), destructively affected the coast of Japan and produced extreme sea level variations. The results of field surveys in the impacted regions showed that multiple deaths and extensive floods were caused by the combined effect of low-frequency sea level raise (storm surges) and intensive high-frequency (HF) tsunami-like waves (meteotsunamis). The data from ten tide gauges for the 2016 event and eight gauges for the 2018 event were used to examine the properties of the observed sea levels, to estimate the relative contribution of the two sea level components and to evaluate their statistical characteristics (maximum wave heights, amplitudes and periods of individual components, etc.). For the 2016 event, we found that the surge heights were from 12 to 35 cm and that the mean contribution of surges into the total observed sea level heights was ~ 39%; the meteotsunami amplitudes were from 22 to 92 cm, and they contributed 61% of the total height. For the 2018 event, storm surges were significantly stronger, from 46 to 170 cm, while HF amplitudes were from 38 to 130 cm; their relative inputs were 67% and 33%, respectively. Combined, they formed total flood heights of up to 120 cm (2016 event) and 288 cm (2018 event). Previously, the contribution of storm seiches (meteotsunamis) in coastal floods had been underestimated, but results of the present study demonstrate that they can play the principal role. What is even more important, they produce devastating currents: according to our estimates, current speeds were up to 3 knots (1.5 m/s) during the Lionrock event and more than 5 knots (2.6 m/s) during Jebi; these strong currents appear to be the main reason for the resulting damage of coastal infrastructure. The most important characteristic of the recorded meteotsunamis is their trough-to-crest maximum height. During the 2016 event, these heights at three stations were > 1 m: 171 cm at Erimo, 109 cm at Hachijojima and 102 cm at Ayukawa. The 2018 event was stronger; maximum meteotsunami wave heights were 257 cm at Gobo, 138 cm at Kushimoto, 137 cm at Kumano and 128 cm at Murotomisaki. The 2018 Gobo height of 257 cm is much larger than historical non-seismic seiche maxima for the Pacific coast of Japan (140–169 cm) estimated by Nakano and Unoki (1962) for the period of 1930–1956.

Experimental Study on Dam-Break-Like Tsunami Surge Impacts on Small Balls Climbing on Different Slopes

2020 ◽  
Vol 14 (06) ◽  
pp. 2050022
Author(s):  
Cheng Chen ◽  
Fangyu Wang ◽  
Hui Lin
Keyword(s):  
Experimental Study ◽  
Dam Break ◽  
Strength Increase ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Tsunami Inundation ◽  
Positive Effects ◽  
Ball Diameter ◽  
Surface Profiles ◽  
Inundation Height

An experimental study was carried out to investigate the tsunami surge impacts on small balls climbing on different slopes. Dam-break flows were generated in a flume to simulate tsunami surge. The water surface profiles at the sluice gate were observed, the tsunami inundation height and the surge velocity in the flume were measured, and the maximum climbing heights of small balls on different slopes were recorded. Results show that the dam-break speed and the tsunami surge strength increase with increasing reservoir water level. The increasing tsunami inundation height, the decreasing ball density, and the decreasing ball diameter have positive effects on the maximum ball climbing height. Based on the normalized experimental data, equations for estimating the maximum ball climbing heights on different slopes were proposed as functions of the inundation height, the ball diameter, and the ball density. The calculated values from the equation are generally within [Formula: see text]% of the measured values in the experimental ranges.

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