• Journal of the Korean earth science society
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• v.32 no.4
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• pp.360-372
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• 2011

In order to clarify the advection and dispersion characteristics of volcanic tephra to be emitted from the Mt. Baekdu, several numerical experiments were carried out using three-dimensional atmospheric dynamic model, Weather and Research Forecast (WRF) and Laglangian particles dispersion model FLEXPART. Four different temporally averaged meteorological values including wind speed and direction were used, and their averaged intervals of meteorological values are 1 month, 10 days, and 3days, respectively. Real time simulation without temporal averaging is also established in this study. As averaging time of meteorological elements is longer, wind along the principle direction is stronger. On the other hands, the tangential direction wind tends to be clearer when the time become shorten. Similar tendency was shown in the distribution of volcanic tephra because the dispersion of particles floating in the atmosphere is strongly associated with wind pattern. Wind transporting the volcanic tephra is divided clearly into upper and lower region and almost ash arriving the Korean Peninsula is released under 2 km high above the ground. Since setting up the temporal averaging of meteorological values is one of the critical factors to determine the density of tephra in the air and their surface deposition, reasonable time for averaging meteorological values should be established before the numerical dispersion assessment of volcanic tephra.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.280-293
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• 2012

In order to clarify the characteristics of dispersion of volcanic tephra emitted from the Mt. Baegdu with various eruption environment, numerical analysis were performed using numerical models, Weather Research and Forecast (WRF) and FLEXPART. Synoptic conditions at 12 October 2010 was adopted because the volcanic ash of Mt. Baegdu can reach the Korean peninsula and its dispersion pattern was compared with different Volcanic Explosivity Index (VEI) and particle size. Predominant size of falling out ash flowing in the peninsular is smaller than 0.5 mm and the ash large than the size is difficult to get in the peninsular due to the its weak ability of truculent diffusion. the difference of ash distribution with various VEI scenarios is not so much but number density of ash in the air is dramatically changed. Volcanic ash tends to be deposited easily in eastern coastal area such as Gangneung and Busan, because of the inflow of ash from East Sea and barrier effect of the Taeback mountains along the east coast of the Korean Peninsula. Accumulated amount of ash deposition can be increased in short period in several urban areas.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.81-84
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• 2002

제주도 동부지역 구좌읍 한동리-송당리를 연결하는 직선상의 4개 지점에서 착정한 심부관측정에 대한 시추코어 지질검층과 심도별 수온ㆍ전기전도도 검층 결과, 제주도를 형성시킨 화산활동과 관련된 화산분출물(용암류 및 쇄설물)은 해수면하 136~170m 범위까지만 분포하고 있고, 그 하부에는 미교결의 U층(U Formation)이 분포하고 있는 것으로 밝혀졌다. 구좌읍 한동리에 소재한 둔지봉(해발 280m)을 경계로 해안지역의 U층 상부에는 용암이 바다속으로 흘러갈 때 생겨나는 베개용암(Pillow Lava)이 분포하고 있음이 최초로 확인되었으며, 이 베개용암층을 통해 고염분지하수가 내륙쪽으로 확산되는 것으로 밝혀졌다. 담수지하수체 하부에 존재하는 고염분 지하수체는 해안에서 내륙쪽으로 오면서 점진적으로 감소하고 기저지하수체(담ㆍ염수 혼합대를 형성하는 지하수체)는 해안으로부터 약 6~6km(해발 120~130m)지역까지 분포하고 있으며, 담수지하수 렌즈체의 두께는 이론적인 G-H비 보다 훨씬 얇은 것으로 나타났다.

• The Journal of the Petrological Society of Korea
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• v.27 no.1
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• pp.49-66
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• 2018

Volcano hazard mapping became a focus of scientific inquiry in the 1960s. Dwight Crandell and Don Mullineaux pioneered the geologic history approach with the concept of the past is the key to the future, to hazard mapping. The 1978 publication of the Mount St. Helens hazards assessment and forecast of an eruption in the near future, followed by the large eruption in 1980 demonstrated the utility of volcano hazards assessments and triggered huge growth in this area of volcano science. Numerical models of hazardous processes began to be developed and used for identifying hazardous areas in 1980s and have proliferated since the late 1990s. Model outputs are most useful and accurate when they are constrained by geological knowledge of the volcano. Volcanic Hazard maps can be broadly categorized into those that portray long-term unconditional volcanic hazards-maps showing all areas with some degree of hazard and those that are developed during an unrest or eruption crisis and take into account current monitoring, observation, and forecast information.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.303-314
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• 2014

Mt. SAKRAJIMA in southern Kagosima, japan is one of the most active volcanoes in the world. On 18 August 2013, the SAKRAJIMA volcano recently went into the largest scaled eruption with a huge plume of volcanic ash. Therefore, the concern arises if this considerable amount of ashes might flow into the Korea peninsula as well as Japan. In this paper, we performed numeric experiment to analyze how volcanic product resulted from the SAKRAJIMA volcano has impacted on Korea. In order to predict the spread pathway of ash, HYSPLIT model and UM data has been used and 17th September 2013 has been selected as observation date since it is expected that the volcanic ash would flow into the South Korea. In addition, we have detected ash dispersion by using optical Communication, Ocean and Meteorological Satellite- Geostationary Ocean Color Imager (COMS-GOCI) images. As the results, we come to a very satisfactory conclusion that the spread pathway of volcanoes based on HYSPLIT model are matched 63.52 % with ash dispersion area detected from GOCI satellites image.