scholarly journals Post-event field survey of 28 September 2018 Sulawesi earthquake and tsunami

2019 ◽  
Vol 19 (12) ◽  
pp. 2781-2794 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Purwanto B. Santoso ◽  
Shih-Chun Hsiao ◽  
Rudy T. Imananta

Abstract. An earthquake with a magnitude of Mw=7.5 that occurred in Sulawesi, Indonesia, on 28 September 2018 triggered liquefaction and tsunamis that caused severe damage and many casualties. This paper reports the results of a post-tsunami field survey conducted by a team with members from Indonesia and Taiwan that began 13 d after the earthquake. The main purpose of this survey was to measure the run-up of tsunami waves and inundation and observe the damage caused by the tsunami. Measurements were made in 18 selected sites, most in Palu Bay. The survey results show that the run-up height and inundation distance reached 10.7 m in Tondo and 488 m in Layana. Inundation depths of 2 to 4 m were common at most sites and the highest was 8.4 m in Taipa. The arrival times of the tsunami waves were quite short and different for each site, typically about 3–8 min from the time of the main earthquake event. This study also describes the damage to buildings and infrastructure and coastal landslides.

2019 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Purwanto B. Santoso ◽  
Shih-Chun Hsiao ◽  
Rudy T. Imananta

Abstract. An earthquake with a magnitude of MW = 7.5 that occurred in Sulawesi, Indonesia on September 28, 2018, triggered liquefaction and tsunamis that caused severe damage and many casualties. This paper reports the results of a post-tsunami field survey conducted by a team with members from Indonesia and Taiwan that began 13 days after the earthquake. The main purpose of this survey was to measure the runup of tsunami waves and inundation and observe the damage caused by the tsunami. Measurements were made in 18 selected sites, most in Palu Bay. The survey results show that the runup height ranged from 2 to 10 m and that the inundation distance was between 80 and 510 m. The highest runup (10.5 m) was recorded in Tondo, a complex that has many boarding houses near a university. The longest inundation distance (511 m) was found in Layana, a marketplace. The arrival times of the tsunami waves were quite short and different for each site, typically about 3–8 minutes from the time of the earthquake event. The characteristics of the damage to buildings, facilities, and structures are also summarized. Several indicators of underwater landslides are described. The survey results can be used for the calibration and validation of hydrodynamic models for tsunamis. They can also be used for regional reconstruction, mitigation, planning, and development.


Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 226 ◽  
Author(s):  
Daniel Giles ◽  
Brian McConnell ◽  
Frédéric Dias

Tsunamis are infrequent events that have the potential to be extremely destructive. The last major tsunami to effect the Irish coastline was the Lisbon 1755 event. That event acts as a candidate worst case scenario for hazard assessment and the impacts on the Irish Coastline are presented here. As there is no general consensus on the 1755 earthquake source, multiple sources highlighted in the literature are investigated. These sources are used to generate the initial conditions and the resultant tsunami waves are simulated with the massively parallelised Volna-OP2 finite volume tsunami code. The hazard associated with the event is captured on three gradated levels. A reduced faster than real time tsunami ensemble is produced for the North-East Atlantic on a regional level in 93 s using two Nvidia V100 GPUs. By identifying the most vulnerable sections of the Irish coastline from this regional forecast, some locally refined simulations are further carried out in a faster than real time setting. As arrival times on the coastline can be on the O (mins), these faster than real time reduced ensembles are of great benefit for tsunami warning. Volna-OP2’s capabilities in this respect are clearly demonstrated here. Finally, high resolution inundation simulations, which build upon the ensemble results, are carried out. To date this study provides the best estimate of assessing the hazard associated with a Lisbon-type tsunami event for the Irish coastline. The results of the inundation mapping highlight that along the vulnerable sections of coastline, inundation is constrained to low-lying areas with maximum run-up heights of 3.4 m being found.


Author(s):  
Miguel Esteban ◽  
Hendra AchiariTomoyuki Takabatake ◽  
Ryota Nakamura ◽  
Takahito Mikami ◽  
Satriyo Panalaran ◽  
...  

At 21:30 local time (UTC+7h) on the 22nd of December 2018 the shorelines of the Sunda Strait, Indonesia, were flooded by tsunami waves. As a result there was widespread destruction and there were 437 casualties, 31,943 injuries, 10 still missing and over 16,000 people displaced (as of the 14th January 2019 National Disaster Management Agency (BNBP), 2019). The tsunami was caused by the flank collapse of the Anak Krakatau volcano (Robertson et al. 2018), located roughly at the centre of the Sunda Strait, which separates eastern Sumatra and western Java islands. Takabatake et al. (2019) performed a field survey of the affected areas. The survey results showed that inundation heights were more than 4 m high along the coastline of Sumatra island (situated to the north-north-east of Anak Krakatau), while less than 4 m were measured along the north-western direction. In Java island Inundation heights of over 10 m were measured at Cipenyu Beach (south-south-eastern direction from Anak Krakatau). However, at the time it was not possible to survey the actual vicinity of Anak Krakatau.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/d6hOT352fj4


2021 ◽  
Vol 502 (2) ◽  
pp. 2266-2284
Author(s):  
Kazuo Makishima ◽  
Teruaki Enoto ◽  
Hiroki Yoneda ◽  
Hirokazu Odaka

ABSTRACT This paper describes an analysis of the NuSTAR data of the fastest-rotating magnetar 1E 1547 − 5408, acquired in 2016 April for a time lapse of 151 ks. The source was detected with a 1–60 keV flux of 1.7 × 10−11 erg s−1 cm−2, and its pulsation at a period of 2.086710(5) s. In 8–25 keV, the pulses were phase-modulated with a period of T = 36.0 ± 2.3 ks, and an amplitude of ∼0.2 s. This reconfirms the Suzaku discovery of the same effect at $T=36.0 ^{+4.5}_{-2.5}$ ks, made in the 2009 outburst. These results strengthen the view derived from the Suzaku data, that this magnetar performs free precession as a result of its axial deformation by ∼0.6 × 10−4, possibly caused by internal toroidal magneti fields (MFs) reaching ∼1016 G. Like in the Suzaku case, the modulation was not detected in energies below ∼8 keV. Above 10 keV, the pulse-phase behaviour, including the 36 ks modulation parameters, exhibited complex energy dependencies: at ∼22 keV, the modulation amplitude increased to ∼0.5 s, and the modulation phase changed by ∼65° over 10–27 keV, followed by a phase reversal. Although the pulse significance and pulsed fraction were originally very low in >10 keV, they both increased noticeably, when the arrival times of individual photons were corrected for these systematic pulse-phase variations. Possible origins of these complex phenomena are discussed, in terms of several physical processes that are specific to ultrastrong MFs.


2018 ◽  
Vol 7 (3) ◽  
pp. 1233
Author(s):  
V Yuvaraj ◽  
S Rajasekaran ◽  
D Nagarajan

Cellular automata is the model applied in very complicated situations and complex problems. It involves the Introduction of voronoi diagram in tsunami wave propagation with the help of a fast-marching method to find the spread of the tsunami waves in the coastal regions. In this study we have modelled and predicted the tsunami wave propagation using the finite difference method. This analytical method gives the horizontal and vertical layers of the wave run up and enables the calculation of reaching time.  


2017 ◽  
Author(s):  
Francesc X. Roig-Munar ◽  
Josep M. Vilaplana ◽  
Antoni Rodríguez-Perea ◽  
José A. Martín-Prieto ◽  
Bernadí Gelabert

Abstract. Large boulders have been found on marine cliffs of 24 study areas of Minorca, Balearic Archipelago. These large imbricated boulders, of up to 229 tonnes, are located on platforms that conform the rocky coastline of Minorca, several tenths of meters from the edge of the cliff, up to 15 m above the sea level, and kilometres away from any inland escarpment. They are mostly located on the southeast coast of the island, and numerical models have identified this coastline as a high tsunami impact zone. The age of the boulders in most of the studied localities show a good correlation with historical tsunamis. Age of the boulders, direction of imbrication and estimation of run-up necessary for their placement, indicate dislodging and transport by North Africa tsunami waves that hit the coastline of Minorca.


Author(s):  
Janaka J. Wijetunge

Purpose This paper aims to describe a multi-scenario assessment of the seismogenic tsunami hazard for Bangladesh from active subduction zones in the Indian Ocean region. Two segments of the Sunda arc, namely, Andaman and Arakan, appear to pose a tsunamigenic seismic threat to Bangladesh. Design/methodology/approach High-resolution numerical simulations of tsunami propagation toward the coast of Bangladesh have been carried out for eight plausible seismic scenarios in Andaman and Arakan subduction zones. The numerical results have been analyzed to obtain the spatial variation of the maximum tsunami amplitudes as well as tsunami arrival times for the entire coastline of Bangladesh. Findings The results suggest that the tsunami heights are amplified on either side of the axis of the submarine canyon which approaches the nearshore sea off Barisal in the seaboard off Sundarban–Barisal–Sandwip. Moreover, the computed tsunami amplitudes are comparatively higher north of the latitude 21.5o in the Teknaf–Chittagong coastline. The calculated arrival times indicate that the tsunami waves reach the western half of the Sundarban–Barisal–Sandwip coastline sooner, while shallow water off the eastern half results in a longer arrival time for that part of the coastline, in the event of an earthquake in the Andaman seismic zone. On the other hand, most parts of the Chittagong–Teknaf coastline would receive tsunami waves almost immediately after an earthquake in the northern segment of the Arakan seismic zone. Originality/value The present assessment includes probabilistic measures of the tsunami hazard by incorporating several probable seismic scenarios corresponding to recurrence intervals ranging from 25 years to over 1,000 years.


2009 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
Mujiyo Mujiyo

<span>The research has aims to know ; (1) the velocity of function displace of the rice field to the non rice field during year period 2000, 2004 and 2008, (2) change grain product during year period 2000, 2004 and 2008, and (3) the relationship between the velocity of function displace of the rice field to the non rice field and the grain production during year period 2000, 2004 and 2008. Function displace of the rice field in the Kebabakkramat District known by determining the wide of each land use type in the appointed year, and then comparing it with data in the next year. The first mapping was based on the Map of Rupa Bumi Bakosurtanal which made in 2000. The second mapping was based on the image QUICK BIRD 2004 which published in the internet media Google Earth. And the third mapping determined by field survey in the 2008. Result of the research shows that ; (1) rice field in the Kebakkramat District along period 2000 until 2008 had function displace, 2.571,89 ha (2000) decreased to become 2.153,33 ha (2004), and decreased again to become 2.128,11 ha (2008), (2) grain production in the Kebakkramat District along period 2000 until 2007 shows increasing trend, 39.880 ton (2000) increased to become 40.631 ton (2003), but decreased to become 35.354 ton (2004), and increased again to become 43.062 ton (2007), (3) although wide of the rice field decreased, but the grain production increased, because increasing its land productivity caused by continuity of the rice field intensification program.</span>


2018 ◽  
Vol 203 ◽  
pp. 01001 ◽  
Author(s):  
Vo Nguyen Phu Huan ◽  
Indra Sati H. Harahap ◽  
Wesam Salah Alaloul

Submarine landslide is the most serious threat on both local and regional scales. By way of addition to destroying directly offshore structures, slope failures may also generate destructive tsunami waves. This study has developed a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method to predict four stages of generation, propagation, run-up, and impact of tsunami phenomenon. The numerical predictions in the research were validated with results in the literature and experimental tests. The results of the physical and numerical results presented in this study effort to develop these rule of thumbs to clearly understand some of the mechanics that may play a role in the assessment of tsunami waves.


2015 ◽  
Vol 9 (6) ◽  
pp. 6471-6493 ◽  
Author(s):  
M. P. Lüthi ◽  
A. Vieli

Abstract. Glacier calving can cause violent impulse waves which, upon landfall, can lead to destructive tsunami-like waves. Here we present data acquired during a calving event from Eqip Sermia, an ocean-terminating glacier in West Greenland. During an exceptionally well documented event, the collapse of 9 × 105 m3 ice from a 200 m high ice cliff caused an impulse wave of 50 m height, traveling at a speed of 25–30 m s-1. This wave was filmed from a tour boat in 800 m distance from the calving face, and simultaneously measured with a terrestrial radar interferometer and a tide gauge. Tsunami wave run-up height on the steep opposite shore in 4 km distance was 10–15 m, destroying infrastructure and eroding old vegetation. These observations indicate that such high tsunami waves are a recent phenomenon in the history of this glacier. Analysis of the data shows that only moderately bigger tsunami waves are to be expected in the future, even under rather extreme scenarios.


Sign in / Sign up

Export Citation Format

Share Document