• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.368-378
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• 2019

Logic trees for probabilistic tsunami hazard assessment include numerous variables to take various uncertainty on earthquake generation into consideration. Results from the hazard assessment vary in different way as more variables are considered in the logic tree. This study is conducted to estimate the effects of various scaling laws and fault parameters on tsunami hazard at the nearshore of Busan. Active fault parameters, such as strike angle, dip angle and asperity, are adjusted in the modelling of tsunami propagation, and the numerical results are used in the sensitivity analysis. The influence of strike angle to tsunami hazard is not as much significant as it is expected, instead, dip angle and asperity show a considerable impact to tsunami hazard assessment. It is shown that the dip angle and the asperity which determine the initial wave form are more important than the strike angle for the assessment of tsunami hazard in the East Sea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.327-334
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• 2011

Simulation of the trans-oceanic or trans-basin propagation of a tsunami is a computer-intensive task. This study demonstrates an effective and detailed visualization technique to deal with the vast amount of surface-elevation and velocity-field output. This high-definition visualization technique is used to present simulations of the 1960 and 2010 Chilean earthquake tsunamis and the 1983 Central East (Japan) Sea earthquake tsunami. This tsunami-visualization method using high-definition graphic animation is an appropriate tool to show detailed tsunami-propagation behavior over an ocean or coastal sea, as exemplified by the Pacific Ocean and East (Japan) Sea tsunami events.

• Journal of the Korean Geophysical Society
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• v.8 no.2
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• pp.93-96
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• 2005

Focal mechanism of the real and imaginary faults in the western coast of Japan has been assumed by examining the previous studies on the seismicity, seismic gap, fault behaviors, seismic zoning, and faults. In the area of no seismic information, the focal mechanism has been assumed to have the maximum influence on the tsunami height in the eastern coast of Korea. The tsunami height in a particular point of the eastern coast of Korea can vary up to 7 orders with the variation of the strike of the fault in a particular source point of the western coast of Japan with constant magnitude. Tsunami scenario DB including the arrival times and tsunami heights has been constructing by using the assumed focal mechanism of the western coast of Japan. Tsunami warning system will be reinforced by using this tsunami scenario DB near future.

• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.255-266
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• 2012

The enormous disaster (Friday nightmare) occurred at 14:46 (JST) (05:46 UTC) on 11 March 2011, officially named "the 2011 Tohoku Earthquake and Tsunami". To monitor the variations of the marine environment after the earthquake, we used chlorophyll and Rrs(555) of GOCI and MODIS ocean color satellite data during March ~ May 2011. Before the earthquake, chlorophyll and Rrs(555) were relatively low around the Sendai areas. After the earthquake;their concentration and intensity were suddenly increased along the coast and the water column was disturbed by the tsunami wave. The severe distortions influenced by the tsunami occurred at less than 30 m water depth and the variations in offshore were difficult to discern the effect of the tsunami. The disturbance by the tsunami was still remained in the terrestrial environment after one month. However the ocean environment returned to the former condition in almost two month later.

• Journal of the Korean Geotechnical Society
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• v.28 no.9
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• pp.31-45
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• 2012

This study was conducted to estimate the stability of a quay wall in case of wave overtopping under the combined action of an earthquake and tsunami using limit equilibrium method. The tsunami force was calculated by using a numerical program called TWOPM-3D (3-D one-field Model for immiscible TWO-Phase flows). Especially, the wave force acting behind the quay wall after a tsunami wave overtopping was estimated by treating back fill as a permeable material. The stability of the quay wall was assessed for both the sliding and overturning modes under passive and active conditions. The variation in the stability of the quay wall with time was determined by parametric studies, including those for the tsunami wave height, seismic acceleration coefficient, internal friction angle of the soil, wall friction angle, and pore water pressure ratio. When the earthquake and tsunami were considered simultaneously, the tsunami induced wave overtopping increased the stability of the quay wall under the passive condition, but in the active condition, the safety factors decreased.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.404-412
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• 1994

On July 12. 1993 at 22 : 17 local time (-9h. KST). an earthquake of surface magnitude (MS) 7.6 occurred on the west coast of the Hokkaido and small of offshore island of Okushiri in the East Sea. A major tsumani was generated and within 2 to 5 minutes, extremely large tsunami waves engulfed the Okushiri coastal area and the central west roast of the Hokkaido. This tsunami caused tremendous casualities and damage. A giant tsunami runup of more than 30 m in height was recorded. The tsunami crossed the East Sea and feeled at 27 sites of the eastern Korean coast during the survey on 17-19, July, 1993. The observed tsunami runup at southern part of the eastern Korean coast were generally weaker than the 1993 Japan Sea Central Earthquake tsunami and varied from 0.8 m to 2.6 m. The Present Paper intends to understand the propagation on this tsunami with the aid of numerical computation model andd computer graphic aided video animation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1489-1494
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• 2013

Tsunami happens rarely enough to allow a false sense of security, but when they do occur, there may be just minutes or hours for people to reach a safe location. Natural disasters like tsunami are inevitable and it is almost impossible to fully recoup damages caused by the disasters. However, it is possible to minimize the potential risk by developing early warning strategies. GIS modelling with its geoprocessing and analysis capability can play a crucial role in efficient mitigation and management of disaster. This study aims at developing integrated spatial information system processing model supporting tsunami evacuation action planning using geo-information technology such as GIS. The integration process classified into four phases. And in each phase, required input data and GIS processes are decided. The main effort in minimizing casualties in tsunami disaster is to evacuate people from the hazard area before tsunami strikes by means of either horizontal or vertical evacuation. The study provides essential spatial information for local decision making related with people's evacuation in tsunami-prone areas based on a modeling approach transferable to other coastal areas.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.21-21
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• 1992

The paper is devoted to one of the branches tsunami. wave hydrodynamics. The theory of propagation, transformation and runup of tsunami waves taking into account the nonlinearity and the dispersion is exposed. The available data on real tsunamis are reviewed.(omitted)

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.261-264
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• 2007

In this study, I wished to forecast damage district by tsunami's occurrence. For this, analyzed tsunami that can happen in our country's neighborhood sea area using past data, and established tsunami's scenario by imagination with analysis result. I created 3D topographical model about study area and analyzed inundation area by achieving simulation by scenario. Also, result of simulation does overlay with digital map and manufactured imagination inundation map. This study result may offer as basic data for operation of tsunami's forecast/alarm system and making of disaster prevention policy.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.7-15
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• 2003

A Digital Wave Tank simulation technique, based on a finite-difference method and a modified marker-and-cell (MAC) algorithm, is applied in order to investigate the characteristics of nonlinear Tsunami propagations and their interactions with a 2D sloping beach, Ohkushiri Island, and to predict maximum wove run-up around the island. The Navier-Stokes (NS) and continuity equation are governed in the computational domain, and the boundary values are updated at each time step, by a finite-difference time-marching scheme in the frame of the rectangular coordinate system. The fully nonlinear, kinematic, free-surface condition is satisfied by the modified marker-density function technique. The near shore Tsunami is assumed to be a solitary wave, and is generated from the numerical wave-maker in the developed Digital Wave Tank. The simulation results are compared with the experiments and other numerical methods, based on the shallow-water wave theory.