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 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. In this study, i propose a model to solve these enigmas. The source rupture histories of the recent 1944 tonankai and 1946 nankai earthquakes were examined extensively based on the analysis of modern instrumental data. Longperiod ground motion simulation of great nankai trough. Tsunami simulation of nankai trough large earthquakes anticipated earthquake scenarios in the nankai trough. Deep slow earthquake families in the nankai trough subduction.
Spatial distribution of centroid moment tensor solutions. Sloshing simulation is performed for oil storage tanks subjected to a possible nankai trough earthquake. Nh23a tsunami scenario in the nankai trough, japan, based on. Because the nankai trough earthquake is likely to cause considerable widespread damage food and other stockpiles need to be for a week or more.
Simulation of recurring earthquakes along the nankai. Modeled ground surface deformation and tsunami inundation for these coupling. A possible scenario for earlier occurrence of the next. Jun 17, 2010 we investigated the effect of delayed rupture of great earthquakes along the nankai trough on tsunami heights on the japanese coast.
The 6th joint meeting of the ujnr panel on earthquake research, 200611910 deep slow earthquake families in the nankai trough subduction zone. The fault is divided into five segments in three zones, which. 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. Therefore, it is now essential to reconsider the scenario of the nankai earthquakes, including the possibility of seismic slip on the shallow subduction interface. 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.
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. A number of scenarios are plausible, including earthquakes occurring simultaneously in multiple. Shizuoka prefecture, located on the pacific side of japan, anticipates major influence due to the nankai trough earthquake. In this study, a slip amount of the shallower part of the plate interface near the trough was set to be an unknown parameter. Quakerecnankai paleotsunami and earthquake records of ruptures along the nankai trough, offshore southcentral japan duration 011020 31122017 budget 1. 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. 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.
Nh23a tsunami scenario in the nankai trough, japan, based. A large suite of scenario rupture modelsis then used to investigate the variabilityoftsunami effects. 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. Longperiod ground motion simulation of great nankai trough, japan, earthquakes. 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. The tonankai earthquake did not rupture fault plane e west of the suruga trough, by some unknown reasons. 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.
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. As the tsunami source, we used a model of the 1707 hoei earthquake, which consists of four segments. Download pdf 833k download meta ris compatible with endnote, reference manager, procite, refworks. 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.
Tsunami scenario in the nankai trough, japan, based on the gpsa and gnss velocities shunichi watanabe japan coast guard, yehuda bock scripps inst. We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the. Megathrust earthquakes are the result of a plate subduction mechanism and occur. Continuous subduction since the late cretaceous has been a common tectonic scenario, althoug. The distribution of type 2 events shows two clear lineaments with strikes of. 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. 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. There is highpossibility of occurrence of huge earthquakes along the nankai trough subduction zone, and the worst scenario is presumed as m w 9. Jul 17, 20 recent evidence suggests that large tsunami with recurrence intervals of several hundred years have occurred along the nankai trough. The rupture zone has been subdivided into five areas with respect to seismic modelling mitsui et al. Abstract great earthquakes have occurred repeatedly along the nankai trough in southwestern japan with recurrence intervals of 100200 years. Longperiod ground motion simulation of great nankai trough, japan, earthquakes takahiro maeda, nobuyuki morikawa, shin aoi, and hiroyuki fujiwara. 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. Full paper open access the possibility of deeper or.
Quakerecnankai paleotsunami and earthquake records of. Cluster analysis of the longperiod groundmotion simulation. Ocean drilling in the nankai trough forearc suggests a new scenario for the evolution of the nankai subduction zone. Moreover, for the next anticipated event, countermeasures should include the possibility of a triggered occurrence of a nankai trough earthquake by an m w. 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. 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. 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. We simulated longperiod ground motion of the nankai trough earthquakes using 55 scenarios with various possible source parameters. Nankai trough, great earthquakes, tsunami, delayed rupture, tsunami.
Mar 26, 2018 modeled ground surface deformation and tsunami inundation for these coupling. Lets usually confirm evacuation site with family so that nankai trough great earthquake may come. Media in category nankai trough megathrust earthquakes the following 41 files are in this category, out of 41 total. 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. Using the gnss data, we estimated the spatiotemporal evolution of longterm aseismic slip along the nankai trough.
Since the nankai trough earthquake is an earthquake that will certainly occur, we must make every effort to prevent. Fullycoupled simulations of megathrust earthquakes and tsunamis. Megathrust earthquakes are the result of a plate subduction mechanism and occur at. Subducted seamount imaged in the rupture zone of the 1946. Reexamination of possible great interplate earthquake. Tsunamitide simulation in a large bay based on the greatest. New seismic activity model of large earthquakes along nankai trough for probabilistic seismic hazard maps toshihiko okumura shimizu corp. To predict future tsunami disasters, we conducted tsunami simulations for potential nankai. Nankai trough megathrust earthquakes wikimedia commons. Estimation of oil overflow due to sloshing from oil. We investigated the effect of delayed rupture of great earthquakes along the nankai trough on tsunami heights on the japanese coast. 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. A strong ground motion of the possible nankai trough earthquake with m w 9.
The hypocenter location rupture start point tends to have a greater impact on longperiod ground motions than the asperities and the rupture areas. Amplification of tsunami heights by delayed rupture of great earthquake along the nankai trough. Longterm slow slip events along the nankai trough subduction. Seafloor geodetic constraints on interplate coupling of the nankai. Tsunami simulations of megathrust earthquakes in the nankai tonankai trough japan based on stochastic rupture scenarios katsuichiro goda1, tomohiro yasuda2, p. 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. Kansai airports today announced that it will hold earthquake and tsunami drills at kansai international airport kix on march 5, 2019.
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. 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. Tsunami simulations of megathrust earthquakes in the. Amplification of tsunami heights by delayed rupture of great. A b map implying the first eastern rupture of the nankai. To evaluate potential hazards and risks due to future devastating. Apr 25, 2019 punctuated growth of an accretionary prism and the onset of a seismogenic megathrust in the nankai trough. The damage estimation on the nankai trough megathrust earthquake. 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. 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 triggered occurrence of an immature nankai trough earthquake could. The possibility of deeper or shallower extent of the. Nankai trough earthquake, hyuganada earthquake, triggered scenario introduction. Shizuoka prefecture earthquake disaster prevention center.
Nankai trough earthquake lets prepare for big earthquake. Earthquake and tsunami drills at kix kansai airports. Previous large earthquakes along the nankai trough. New seismic activity model of large earthquakes along nankai. If a magnitude 8 class earthquake occurs along the nankai trough in this case, the. Full paper open access the possibility of deeper or shallower. In order to simulate sloshing of oil storage tanks subjected to a possible nankai trough earthquake, ground shaking characteristics of the site need. Coseismic slip resolution along a plate boundary megathrust. Promotion of disaster prevention and reduction to overcome. Tsunami simulation for the great 1707 hoei, japan, earthquake. Simulate longperiod ground motions for anticipated nankai trough earthquake m8. 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.
Estimation of oil overflow due to sloshing from oil storage. 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. Tsunamitide simulation in a large bay based on the. The scenario of this case was developed based on the most recent two cases where major earthquakes occurred in a row. On 31 march 2012, the central disaster management council announced the predictions of forthcoming largescale hazards, which. We first searched for the worst case, in terms of coastal tsunami heights, of. Our results indicate that triggering can explain the variety and complexity of historical nankai trough earthquakes. The recently proposed nankai trough earthquake scenario mw 9 has a maximum slip of 20 m near the trough axis. 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. Deep slow earthquake families in the nankai trough. The possibility of deeper or shallower extent of the source. Additional large megathrust events on the nankai trough. Pdf tsunami simulations of megathrust earthquakes in the.
Pdf amplification of tsunami heights by delayed rupture. Chapter 3 preparedness for nankai trough major earthquakes. Pdf amplification of tsunami heights by delayed rupture of. The recently proposed nankai trough earthquake scenario m w 9 has a maximum slip of 20 m near the trough. A large slip near the nankai trough of the 1854 ansei. 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. The historical records imply that potential tsunamis generated in the nankai trough region could affect the korean peninsula in the future.
Seafloor geodetic constraints on interplate coupling of. Simulation of recurring earthquakes along the nankai trough. 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. 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. The nankai trough is the nearsurface extension of a zone of active seismicity that dips beneath sw japan.
According to the ukrainian researcher, vjacheslav nagorny, an undersea megathrust earthquake off the coast of japan m 8. Amplification of tsunami heights by delayed rupture of. This irregular behavior suggests that in addition to the regular nankai. Geodetic survey measurements are used to estimate the coseismic slip distribution in the 1944 tonankai mw8. Portresolving, tsunami, and tidal simulations to locate.
Punctuated growth of an accretionary prism and the onset of a seismogenic megathrust in the nankai trough. A possible scenario for earlier occurrence of the next nankai. Nankaido earthquake japan december 20, 1946 devastating. Kuroshio town came to be known as the place of the worstcase scenario of the probable nankai trough earthquake. The nankai trough was frequently hit in the past by powerful earthquakes. 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. Reexamination of possible great interplate earthquake scenarios in the nankai trough, southwest japan, based on recent findings and numerical simulations. Based on a scenario in which a major tsunami warning is issued for osaka prefecture following a magnitude 9. 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. Tsunami accumulation footprints inundation from the 2011 great east japan tohoku earthquake. Longperiod ground motion simulation of great nankai. We considered another scenario for the nankai great interplate earthquake cycles based on recent studies that suggested. Historically, the nankai earthquake occurs every 100 to 150 years. Tsunami accumulation footprints inundation from the 2011 great east japan tohoku.
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