May 20, 2019 even though earthquake prone japan has seen numerous warnings that massive, devastating temblors could strike at any time, including in the tokyo metropolitan area and in the nankai trough off the. Tsunami simulations of megathrust earthquakes in the nankai tonankai trough japan based on stochastic rupture scenarios katsuichiro goda1, tomohiro yasuda2, p. To validate the abundance of scenarios of large earthquakes in the nankai trough, we examined the effects of both lateral and vertical expansions of the source areas on maximum tsunami heights along the pacific coast and seto inland sea. Tsunami accumulation footprints inundation from the 2011 great east japan tohoku earthquake. Even though earthquakeprone japan has seen numerous warnings that massive, devastating temblors could strike at any time, including in the tokyo metropolitan area and in the nankai trough off the. A number of scenarios are plausible, including earthquakes occurring simultaneously in multiple. Tsunami scenario in the nankai trough, japan, based on the gpsa and gnss velocities shunichi watanabe japan coast guard, yehuda bock scripps inst. Full paper open access the possibility of deeper or shallower. Longperiod ground motion simulation of great nankai trough, japan, earthquakes takahiro maeda, nobuyuki morikawa, shin aoi, and hiroyuki fujiwara. A possible scenario for earlier occurrence of the next nankai.
Shizuoka prefecture earthquake disaster prevention center. The 1946 nankaido earthquake was unusual, with a rupture zone estimated from longperiod geodetic data that was more than twice as large as that derived from shorter period seismic data. These big data of simulation data were calculated by a three dimensional finite difference method for megathrust earthquakes in the nankai trough using various source models earthquake scenarios with different source area, rupture starting point, asperity, rupture velocity, source time function and fmax. Scope of japan earthquake model update 2012 new subduction interface sources. According to the ukrainian researcher, vjacheslav nagorny, an undersea megathrust earthquake off the coast of japan m 8. Modeled ground surface deformation and tsunami inundation for these coupling. The underlying fault, the nankai megathrust, is the source of the devastating nankai megathrust earthquakes, while the trough itself is potentially a major source of hydrocarbon. On december 20, 1946, while japan was recovering from all the devastation of world war ii, it was hit once again with the nankaido earthquake, a very powerful one of magnitude 8. Recently, through similar numerical simulations of interplate seismic cycles along only the western half of the nankai trough from kyushu to shikoku, nakata et al. The historical records imply that potential tsunamis generated in the nankai trough region could affect the korean peninsula in the future. Nw a v vp o z v a vp v u v it is necessary to carefully disseminate information related to the nankai trough earthquake so that the people can have an accurate understanding. The nankai trough is a vigorous subduction zone where large earthquakes have been recorded since the seventh century, with a recurrence time of 100 to 200 years. We considered another scenario for the nankai great interplate earthquake cycles based on recent studies that suggested. Mar 14, 2017 a group of governmentappointed scientists warned tuesday that a major earthquake in the nankai trough off the pacific coast could leave as many as 1.
We first searched for the worst case, in terms of coastal tsunami heights, of. On 31 march 2012, the central disaster management council announced the predictions of forthcoming largescale hazards, which. A possible scenario for earlier occurrence of the next. Tsunami simulations of megathrust earthquakes in the nankaitonankai trough japan based on stochastic rupture scenarios. Seafloor geodetic constraints on interplate coupling of. The nankai trough, nankai torafu, southern sea trough is a submarine trough located south of the nankaido region of japans island of honshu, extending approximately 900 km offshore. The 6th joint meeting of the ujnr panel on earthquake research, 200611910 deep slow earthquake families in the nankai trough subduction zone. Tsunami simulation of nankai trough large earthquakes anticipated earthquake scenarios in the nankai trough. The possibility of deeper or shallower extent of the. Chapter 3 preparedness for nankai trough major earthquakes. Quakerecnankai paleotsunami and earthquake records of. New seismic activity model of large earthquakes along.
If the abovementioned worstcase scenario happens, it is likely to disrupt the society and lead to a nationallevel crisis. Moreover, for the next anticipated event, countermeasures should include the possibility of a triggered occurrence of a nankai trough earthquake by an m w 7 hyuganada earthquake. Nh23a tsunami scenario in the nankai trough, japan, based on. Nankaido earthquake japan december 20, 1946 devastating. Estimation of oil overflow due to sloshing from oil storage. A large suite of scenario rupture modelsis then used to investigate the variabilityoftsunami effects. Simulation of recurring earthquakes along the nankai. The tonankai earthquake did not rupture fault plane e west of the suruga trough, by some unknown reasons. Additional large megathrust events on the nankai trough. Simulation of recurring earthquakes along the nankai trough. Nankai trough earthquake lets prepare for big earthquake. Deep slow earthquake families in the nankai trough subduction.
The tokai earthquake anticipated at fault plane e has not occurred yet since the anseitokai event even if a slow slip event occurred recently near the downdip end of its rupture zone. Longperiod ground motion simulation of great nankai trough. Moreover, for the next anticipated event, countermeasures should include the possibility of a triggered occurrence of a nankai trough earthquake by an m w. This study simulated tsunamiinduced vortexes in osaka bay and investigated their spatial and temporal scales using a portresolved, highresolution tsunami model based on a scenario for the largest tsunamigenic earthquake expected to occur along the nankai trough in the near future. The global navigation satellite system gnss network in japan has detected transient crustal deformation in regions along the nankai trough subduction zone in southwest japan from approximately 20, after the 2011 tohoku earthquake. As the tsunami source, we used a model of the 1707 hoei earthquake, which consists of four segments.
There is highpossibility of occurrence of huge earthquakes along the nankai trough subduction zone, and the worst scenario is presumed as m w 9. Apr 21, 2017 the global navigation satellite system gnss network in japan has detected transient crustal deformation in regions along the nankai trough subduction zone in southwest japan from approximately 20, after the 2011 tohoku earthquake. Shizuoka prefecture, located on the pacific side of japan, anticipates major influence due to the nankai trough earthquake. Kuroshio town came to be known as the place of the worstcase scenario of the probable nankai trough earthquake. Punctuated growth of an accretionary prism and the onset of a seismogenic megathrust in the nankai trough.
We simulated longperiod ground motion of the nankai trough earthquakes using 55 scenarios with various possible source parameters. Quakerecnankai paleotsunami and earthquake records of ruptures along the nankai trough, offshore southcentral japan duration 011020 31122017 budget 1. Nankai megathrust earthquakes are great megathrust earthquakes that occur along the nankai megathrust the fault under the nankai trough which forms the plate interface between the subducting philippine sea plate and the overriding amurian plate part of the eurasian plate, which dips beneath southwestern honshu, japan. Tsunami simulation for the great 1707 hoei, japan, earthquake. Punctuated growth of an accretionary prism and the onset.
To predict future tsunami disasters, we conducted tsunami simulations for potential nankai. The distribution of type 2 events shows two clear lineaments with strikes of. Subducted seamount imaged in the rupture zone of the 1946. Estimation of oil overflow due to sloshing from oil.
The damage estimation on the nankai trough megathrust earthquake. Using the gnss data, we estimated the spatiotemporal evolution of longterm aseismic slip along the nankai trough. Download pdf 833k download meta ris compatible with endnote, reference manager, procite, refworks. Deep slow earthquake families in the nankai trough. Longperiod ground motion simulation of great nankai. Nankai trough earthquake, hyuganada earthquake, triggered scenario introduction. Nh23a tsunami scenario in the nankai trough, japan, based. This study investigated the influences of a giant tsunami on salinity in coastal waters based on the scenario of the largest potential tsunamigenic earthquake that could occur along the nankai trough in the near future, by conducting an oceantsunami coupled threedimensional simulation in. Nankai trough, great earthquakes, tsunami, delayed rupture, tsunami. Amplification of tsunami heights by delayed rupture of. The hypocenter location rupture start point tends to have a greater impact on longperiod ground motions than the asperities and the rupture areas. The fault is divided into five segments in three zones, which. New seismic activity model of large earthquakes along nankai.
Tsunami accumulation footprints inundation from the 2011 great east japan tohoku. Reexamination of possible great interplate earthquake. In this study, i propose a model to solve these enigmas. Geodetic survey measurements are used to estimate the coseismic slip distribution in the 1944 tonankai mw8. The scale of this earthquake was quite small, meaning there is still a great deal of stress left to be released. Cluster analysis of the longperiod groundmotion simulation. Spatial distribution of centroid moment tensor solutions. However, the predicted tsunami heights exceeded those obtained from historical records of damage caused by the 1707 hoei tsunami event at tosa bay and along the pacific coastlines near the kii channel, owing to the.
The occurrence of the next nankai trough earthquake will initially be observed by highsensitivity geophysical monitoring networks, such as hinet 1, geonet 2, donet 3, and gpsa 4, 5. A b map implying the first eastern rupture of the nankai. Promotion of disaster prevention and reduction to overcome. The rupture zone has been subdivided into five areas with respect to seismic modelling mitsui et al. The possibility of deeper or shallower extent of the source. Lets usually confirm evacuation site with family so that nankai trough great earthquake may come. Pdf amplification of tsunami heights by delayed rupture. Tsunamitide simulation in a large bay based on the greatest. Nankai trough megathrust earthquakes wikimedia commons. Abstract great earthquakes have occurred repeatedly along the nankai trough in southwestern japan with recurrence intervals of 100200 years.
Sloshing simulation is performed for oil storage tanks subjected to a possible nankai trough earthquake. Portresolving, tsunami, and tidal simulations to locate. Jul 19, 20 1 many earthquakes of moment magnitudes greater than 8 associated with subduction of the philippine sea plate under japan have occurred along the nankai trough with a recurrence interval of 90150 years. Pdf amplification of tsunami heights by delayed rupture of. Since the nankai trough earthquake is an earthquake that will certainly occur, we must make every effort to prevent. The recently proposed nankai trough earthquake scenario mw 9 has a maximum slip of 20 m near the trough axis. Development of longperiod ground motions from the nankai. Full paper open access the possibility of deeper or. The source models capture a wide range of realistic slip distributions and kinematic rupture processes, reflecting the current best understanding of what may happen due to a future megaearthquake in the nankaitonankai trough, and therefore are useful for conducting probabilistic tsunami hazard and risk analysis. Reexamination of possible great interplate earthquake scenarios in the nankai trough, southwest japan, based on recent findings and numerical simulations. A group of governmentappointed scientists warned tuesday that a major earthquake in the nankai trough off the pacific coast could leave as many as 1. Note the momentum magnitudes mw are based on the report of the working group on the crite ria of anomalous phenomena along the nankai trough for disaster risk management december 2018. Amplification of tsunami heights by delayed rupture of great. New seismic activity model of large earthquakes along nankai trough for probabilistic seismic hazard maps toshihiko okumura shimizu corp.
The observational data and a corresponding computer simulation for the earthquake clearly demonstrate that such longperiod ground motion is primarily developed as the wave propagating along the nankai trough due to the ampli. If a magnitude 8 class earthquake occurs along the nankai trough in this case, the. In this study, a slip amount of the shallower part of the plate interface near the trough was set to be an unknown parameter. Tsunamitide simulation in a large bay based on the. Mar 26, 2018 modeled ground surface deformation and tsunami inundation for these coupling. Apr 25, 2019 punctuated growth of an accretionary prism and the onset of a seismogenic megathrust in the nankai trough. This irregular behavior suggests that in addition to the regular nankai. To evaluate potential hazards and risks due to future devastating. Jul 17, 20 recent evidence suggests that large tsunami with recurrence intervals of several hundred years have occurred along the nankai trough. We investigated the effect of delayed rupture of great earthquakes along the nankai trough on tsunami heights on the japanese coast. Continuous subduction since the late cretaceous has been a common tectonic scenario, although the plate subduction was transferred from the pacific plate to the philippine sea plate during the miocene. Kansai airports today announced that it will hold earthquake and tsunami drills at kansai international airport kix on march 5, 2019. Seafloor geodetic constraints on interplate coupling of the nankai. Fullycoupled simulations of megathrust earthquakes and tsunamis.
Coseismic slip resolution along a plate boundary megathrust. A large slip near the nankai trough of the 1854 ansei. Therefore, it is now essential to reconsider the scenario of the nankai earthquakes, including the possibility of seismic slip on the shallow subduction interface. Previous large earthquakes along the nankai trough. Mar 16, 2018 the occurrence of the next nankai trough earthquake will initially be observed by highsensitivity geophysical monitoring networks, such as hinet 1, geonet 2, donet 3, and gpsa 4, 5. Pdf tsunami simulations of megathrust earthquakes in the. The source rupture histories of the recent 1944 tonankai and 1946 nankai earthquakes were examined extensively based on the analysis of modern instrumental data, such as tide gauge records of tsunami waveforms, seismograms, and geodetic data. A strong ground motion of the possible nankai trough earthquake with m w 9. Tsunami simulations of megathrust earthquakes in the nankai. The recently proposed nankai trough earthquake scenario m w 9 has a maximum slip of 20 m near the trough axis.
Amplification of tsunami heights by delayed rupture of great earthquake along the nankai trough. The nankai trough is the nearsurface extension of a zone of active seismicity that dips beneath sw japan. Because the nankai trough earthquake is likely to cause considerable widespread damage food and other stockpiles need to be for a week or more. Tsunami simulations of megathrust earthquakes in the. A tsunami propagation under the scenario was simulated based on a. Earthquake and tsunami drills at kix kansai airports. The scenario of this case was developed based on the most recent two cases where major earthquakes occurred in a row.
This study investigated the influences of a giant tsunami on salinity in coastal waters based on the scenario of the largest potential tsunamigenic earthquake that could occur along the nankai trough in the near future, by conducting an oceantsunami coupled threedimensional simulation in osaka bay. The nankai trough was frequently hit in the past by powerful earthquakes. Megathrust earthquakes are the result of a plate subduction mechanism and occur. Longterm slow slip events along the nankai trough subduction. Simulate longperiod ground motions for anticipated nankai trough earthquake m8.
We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the. Sep 25, 2014 to validate the abundance of scenarios of large earthquakes in the nankai trough, we examined the effects of both lateral and vertical expansions of the source areas on maximum tsunami heights along the pacific coast and seto inland sea. The source rupture histories of the recent 1944 tonankai and 1946 nankai earthquakes were examined extensively based on the analysis of modern instrumental data. Megathrust earthquakes are the result of a plate subduction mechanism and occur at. The triggered occurrence of an immature nankai trough earthquake could. In order to simulate sloshing of oil storage tanks subjected to a possible nankai trough earthquake, ground shaking characteristics of the site need. The recently proposed nankai trough earthquake scenario m w 9 has a maximum slip of 20 m near the trough. Based on a scenario in which a major tsunami warning is issued for osaka prefecture following a magnitude 9. Longperiod ground motion simulation of great nankai trough, japan, earthquakes. Historically, the nankai earthquake occurs every 100 to 150 years. Media in category nankai trough megathrust earthquakes the following 41 files are in this category, out of 41 total. Our results indicate that triggering can explain the variety and complexity of historical nankai trough earthquakes. The magnitudes of nankai earthquakes have historically varied, with many studies to date asserting that an events magnitude is controlled only by the number of broken segments arranged along the trough. Earthquakes of type 1 are distributed inside the philippine sea plate beneath the nankai trough, while normalfault events predominate in the other regions along the trough.
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