On 28 September 2018, a strong earthquake with moment magnitude of 7.5 occurred on the island Sulawesi, Indonesia. This caused extensive liquefaction and liquefaction-induced flow slides inland. Despite strike-slip fault, which typically displaces land horizontally, being unlikely to produce significant tsunamis, in fact devastating tsunamis. Our field investigations showed that there was an occurrence coastal areas. Significant can result gravity liquefied soil mass cause tsunami. A...

AbstractPropagation and inundation characteristics of the 2011 Tohoku tsunami on central Sanriku coast are investigated through field surveys numerical simulations using offshore wave recordings as incident conditions. The model successfully reproduces extent flood areas well distribution heights along intricate coastline except for run-up extreme over steep slopes. survey computed results suggest significant variations coastline. Their positive dependency topographic slopes implies that...

Abstract The development of bedforms under unidirectional, oscillatory and combined‐flows results from temporal changes in sediment transport, flow morphological response. In such flows, the bedform characteristics (for example, height, wavelength shape) change over time, their initiation to equilibrium with imposed conditions, even if conditions remain unchanged. These variations morphology during are reflected sedimentary structures preserved rock record. Hence, understanding time which...

The Wharton Basin, off southwest Sumatra, ruptured to a large intraplate left-lateral strike-slip Mw 7.8 earthquake on 2016 March 2. epicentre was located ∼800 km the south of another similar-mechanism 8.6 in same basin 2012 April 11. Small tsunamis from these earthquakes were registered with maximum amplitudes 0.5−1.5 cm DARTs and 1−19 tide gauges for event, respective values 0.5−6 6−40 event. By using both teleseismic body waves tsunami observations we obtained optimum slip models rupture...

Abstract Typhoon Lionrock, also known as the national number 1610 in Japan, caused severe flooding east Japan August 28–31, 2016, leaving a death toll of 22. With maximum sustained wind speed ~ 220 km/h from Joint Warning Center’s best track, Lionrock was classified category 4 hurricane Saffir–Simpson Hurricane Wind Scale and typhoon Meteorological Agency’s scale. among unique typhoons it started its landfall north Japan. Here, we studied characteristics this through tide gauge data...

Storm surges may bring catastrophic damage to coasts by the abnormal increase in sea level. In semi-enclosed, shallow water areas such as Tokyo Bay, of level due wind tends be significant. Due this characteristic, fast-moving typhoon can regarded a potential candidate for possible maximum storm surge Japan. The moving speed Super Typhoon Vera 1959 (i.e. 73 km/h), which caused worst Japan, is about two times faster than average around Japan (Yamaguchi et al. 2020) but typically used...

Abstract The April 2016 Ecuador M w 7.8 earthquake was the first megathrust tsunamigenic along Ecuador‐Colombia subduction zone since 1979 ( 8.2 with 200 deaths from tsunami). While there no tsunami damage earthquake, small tsunamis were recorded at Deep‐ocean Assessment and Reporting of Tsunami tide gauges. Here we designed various fault models without shallow‐slip area compared computed teleseismic waveforms observations. inversions indifferent about inclusion or exclusion shallow slip,...

The actions of wind and atmospheric pressure associated with tropical cyclones (e.g. typhoons) are considered the primary factors behind generation storm surges, though fields used in meteorological models can sometimes deviate from observations. To improve these, direct modification method (DMM) has been previously proposed, this only modifies field a typhoon, further development is necessary for applying it to surge hindcasts. present work describes semi-empirical gradient balance-based...

The thermoluminescence (TL) properties of feldspar were used to investigate the sediment movement processes in a fluvial–coastal system. Field samples collected at various locations along Tenryu River and Enshunada Coast Japan. After series pretests, an appropriate TL measuring sequence was proposed for this study. Applying approach, natural intensity grains measured. Owing young age research area, it assumed that difference ascribed sample depositional environment under which different...

On 16 September 2015, a Mw 8.3 earthquake occurred off the coast of Illapel, Central Chile, generating tsunami that caused moderate damage along Chile. To investigate and evacuation responses, we conducted post-tsunami field survey between La Serena Concón. The average inundation height in area was 3–4 m; however, innermost corner Coquimbo Bay, which shielded from source by Peninsula, 6.0–6.2 m, decreasing gradually away corner. This phenomenon also confirmed around Tongoy is geographically...

A new tsunami source inversion method is proposed, which includes both effects of spatio-temporal evolution and estimation permanent deformation at observation points. The was applied to the 2011 off Pacific coast Tohoku tsunami. accuracy wave prediction significantly improved by this method. Ridge-shaped sea-surface uplift along Japan Trench with maximum height about 7 m estimated in inversion. thought be origin waveforms a sharp peak were recorded northern applicability real-time verified...

We studied ocean-wide propagation properties of four recent trans-Pacific tsunamis based on deep-ocean measurements across the Pacific Ocean. First, we analysed and simulated 2015 September 16 tsunami generated by Illapel (Chile) earthquake (Mw 8.4) compared its with those three other events: 2014 Iquique 8.2), 2010 Maule 8.8) 2011 Tohoku 9.0). The sources are located close to each reconstructed source spectrum larger (i.e. Maule) applying spectral deconvolution using smaller Illapel) as...

Abstract The 1923 Great Kanto earthquake occurred on September 1, in Japan, and caused severe damage mainly the region. Tsunamis were observed over wide regions from east coast of Izu Peninsula to west Boso Peninsula, particularly, Atami was devastating. Many fault models including those Kanamori (1971) Ando proposed based records land deformation. However, such cannot sufficiently explain tsunami elevation its initial sea-level motion coasts. Hence, detailed mechanisms remain elusive. This...

In this research, we develop a numerical fluid simulator coupled with structural analysis. The purpose of system is to efficiently calculate all stages tsunami from source runup, including deformation. We also investigate the stability breakwaters at Kamaishi port. results are compared physical experiments, revealing good agreement. applied local conditions port verify its applicability. Most washed away, which similar actual reported damage, indicating that proposed can effectively reproduce damage.

The present study conducts a series of hindcast simulations for Typhoon Haiyan storm surges and waves using coupled model surge wave (SuWAT) with changing typhoon radius in 30 km, 40 50 70 80 satellite observation as well wind velocity limit the dependent drag coefficient. results indicate that radiuses km are reasonable to calculate along Leyte Gulf. m/s speed coefficient is acceptable comparison field survey results. Further study, which includes inundation modeling, required assess more accurate.

During the 2011 off Pacific Coast of Tohoku Earthquake Tsunami, large vessels that could not escape to safe fields in tsunami-affected areas were helplessly transported by tsunami-induced currents. The positions a vessel time are analyzed from data obtained with Automatic Identification System (AIS) which obliged install International Convention for Safety Life at Sea. AIS on Port Kashima during tsunami is utilized numerical simulation tsunami-transported port. Further, validation...

Distributions of inundation and runup height for the 2011 off Pacific coast Tohoku Earthquake Tsunami were measured in outside Yamada Bay located at center Iwate Prefecture, Japan. Numerical simulations conducted to reproduce flow, distributions. Surface elevation profiles recorded by GPS wave gauges used as offshore boundary condition. In order investigate characteristics tsunami response different geomorphological features, frequency separation was tried incident wave. It found that high...

Sediments indicating a rapid fall in lake level have been discovered the late Pleistocene Gokarna Formation, Kathmandu Valley, Nepal. The indicators are observed along widely traceable erosional surface this formation, and is characterized by (1) gently inclined (ca. 10°) tabular cross-stratified sand beds of delta front deposits consisting coarser material showing gradual decrease elevation its top to progradation direction, (2) an antidune cross-laminated bed that interfingers with...

本研究では，津波来襲時の防護施設の被災状態を考慮した津波浸水予測モデルの構築を目的とし，津波規模と防護施設の被災度の関係を示すフラジリティカーブを用いたモデルを開発した．そのモデルは，来襲する津波規模に応じて，フラジリティカーブから防護施設の被災度を推定し，その被災度に応じた防護施設の防護性能の低下をモデル化するものであり，本検討では性能低下を越流量の増加と捉え，モデルを構築した．本検討で開発したモデルを用いて，テスト計算および高知県浦戸湾を対象とした現地適用計算を実施した結果，防護施設健全と全倒壊の間の結果となり妥当な結果が得られた．また，防護施設の天端高を実際に下げて計算した結果と比較すると，概ね30%程度の天端高減少と同様の結果となることが分かった．一方で，津波高から平均的な損傷度を求めると40%程度となり妥当な結果を得た．