• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.188-188
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• 2011

작년 아이슬란드에서의 화산폭발로 발생된 화산재가 대기 중으로 이동하면서 유럽 공항 곳곳의 항공기 수천 편이 운항 중지되기도 하였다. 한반도내의 백두산은 약 1000전(서기 946년~947년 경) 대규모로 분화하였고, 서기 1903년, 소규모 분화한 후, 앞으로 수년~수십 년 사이에 폭발적인 분화를 재개할 가능성이 제기되고 있으며, 백두산 분화 시, 아이슬란드 화산폭발 때보다 훨씬 심각한 피해가 예상되고 있다. 따라서 백두산 화산에 대한 현지 자료의 수집과 꾸준한 모니터링(감시, 관측) 자료의 분석과 재해 예상 범위 및 대응 방안의 모색이 필요한 시점이다. 본 연구에서는 지리적으로 가까이 있으며 108개 활화산의 화산재해 방재에 관하여 꾸준히 활동하고 있는 일본에서의 화산감시 및 분화대응 시스템을 파악하고, 우리나라의 화산재해대책을 수립하기위한 시사점들을 고찰하였다. 화산의 평균적인 분화 간격은 풍수해나 지진 등 다른 재해에 비해 길기 때문에 일본 기상청에서는 과거１만년 이내에 분화한 증거가 있는 화산이 활화산으로서 인정되고 있다. 백두산은 약 1000년 전에 분화한 뒤 최근 분화의 전조현상을 보이고 있으며, 중국과 북한에 인접하여 있으므로 우리나라에 직접적인 피해는 예상되지 않으나, 우리나라에 일본과 같은 활화산이 존재하지 않기 때문에 생소하였던 화산재해란 어떠한 것이며, 향후 잠재적인 분화 가능성을 가지고 있는 백두산폭발로 인한 재해의 종류를 미리 예상하고 준비할 필요가 있다. 일본의 경우 계속적인 감시와 관측을 통한 분화예보, 경보를 발령하고 분화 시 즉각적인 방재정보를 전달, 지역주민들이 빠르게 인지, 주의하도록 화산재해 대책 시스템이 갖추어져 있다. 우리나라는 아직 중국과 북한에 인접한 백두산에 대한 관측 자료가 거의 없고, 연구를 위한 접근 또한 쉽지 않은 상황이다. 분화로 인한 직접적인 영향권에서는 벗어난다할지라도 계절적인 기상장의 영향 및 아직 예측 불가능한 백두산의 잠재적인 폭발규모에 따라 간접적인 영향을 받을 경우에 대비하여야 할 필요성이 있다고 사료된다. 또한 우리나라의 화산재해 방재력을 향상시키기 위하여 백두산 폭발로 인한 재해위험범위를 가시화하고, 분화 시에 대한 구체적인 가상시나리오를 작성하여, 화산재 및 대기오염물질의 확산시뮬레이션, 기후변화에 끼치는 영향 등을 포함하는 화산재해대책을 미리 세워 피해를 저감시킬 수 있는 방재대책을 수립해야 할 것이다.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.513-527
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• 2018

We have carried out granulometry and component analysis on pyroclastic deposits of the Maljandeung Tuff, Ulleung Island, to interpret the eruption types and prime dynamic mechanisms. It is divided into three members in the extracaldera area, each of which comprises the lithofacies of coarse tuffs and lapillistones in the lower part, and pumice deposits in upper one. The lithofacies present quantitative evidences in the granularity and component distribution patterns. As compared to the pumice deposits, the coarse tuffs and lapillistones exhibit a relative increase in both the lithic/juvenile and the crystal/juvenile ratios, and a preferential fragmentation of the juvenile fraction. The abundance of lithics and crystals in the tuffs and lapillistones can be attributed to preferential fragmentation of the aquifer-hosting rocks due to explosive evaporation of ground water, and indirect enrichment in lithics and crystals due to removal of juvenile fines from eruptive cloud. The above data exhibit that early phreatopmagmatic phase was followed by purely magmatic fragmentation phases. The coarse tuffs and lapillistones suggest phreatoplinian eruption derived from explosive interaction of magma with ground water near the conduit, while pumice deposits indicate magmatic eruption by magmatic explosion from juvenile gas pressure. In early stage, phreatoplinian eruption occurred from explosive magma/water interaction in connecting confining water with drawdown of the magma column in the conduit; Later it shifted to plinian eruption by explosive expansion of only magmatic volatiles in intercepting water influx due to higher magmatic gas pressure than confining water pressure with rising of the magma column in the conduit.

• Journal of the Korean earth science society
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• v.38 no.2
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• pp.115-128
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• 2017

Aso caldera volcano is located in central Kyushu, Japan which is one of the largest caldera volcanoes in the world. Nakadake crater is the only active central cone in Aso caldera. There was an explosive eruption on October 8, 2016, the eruption column height was 11 km, and fallout ash was found 300 km away from the volcano. In this study, we performed a numerical simulation to analyze the ash dispersion and the fallout tephra deposits during this eruption using Ash3D that was developed by the United States Geological Survey. The result showed that the ash would spread to the east and northeast, that could not affect the Korean peninsula, and the volcanic ash was deposited at a place from a distance of 400 km or more in the direction of east and northeast. The result was in close agreement with the identified ashfall deposits. Ash3D can be useful for quick forecast for the effects of hazards caused by volcanic ash.

• Journal of the Korean earth science society
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• v.37 no.6
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• pp.346-358
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• 2016

This study built the volcano Data Base(DB) of 289 active volcanoes around the Korean Peninsula, Japan, China (include Taiwan), and Russia Kamchatka area. Twenty nine more hazardous volcanoes including Baekdusan, Ulleungdo and 27 Japanese volcanoes that can cause a widespread ash-fall on the Korean peninsula by potentially explosive eruption were selected. This selection was based on the presence of volcanic activity, whether or not containing dangerous explosive eruption rock types, distance from Seoul, and volcanoes having Plinian eruption history with volcanic explosivity index (VEI) 4 or more. The results of this study are utilized for screening high-risk volcanoes that may affect the volcanic disaster caused by a widespread fallout ash. By predicting the extent of spread of ash caused by these hazardous volcanic activities and by analyzing the impact on the Korean peninsula, we suggest that it should be used for helping to predict volcanic ash damages and conduct hazards mitigation research as well.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.293-305
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• 2020

An eruption of Taal Volcano in the Philippines began on January 12, 2020. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) subsequently issued an Alert Level 4, indicating that "a hazardous explosive eruption is possible within hours to days." It was a phreatic eruption and phreatomagmatic eruption from the main crater that spewed ashes to Calabarzon, Metro Manila, some parts of Central Luzon, and Pangasinan in Ilocos Region, resulting in the suspension of classes, work schedules, and flights. By January 26, 2020, PHIVOLCS observed inconsistent, but decreasing volcanic activity in Taal, prompting the agency to downgrade its warning to Alert Level 3. After February 14, Alert status was set to Level 2 because of overall decreasing trend of volcanic activities, but it does not mean that the threat of an eruption has disappeared. In addition, the Alert Level can be raised to Alert Level 3 if there is a symptom of increasing unrest at any time.

• The Journal of the Petrological Society of Korea
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• v.23 no.4
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• pp.351-366
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• 2014

We assumed the situation where an eruption column had been formed by the explosive Plinian eruption from Mt. Baekdu and that the collapse of eruption column had caused pyroclastic density currents to occur. Based on this assumption, we simulated by using a Titan2D model. To find out about the range of the impacts of pyroclastic density currents by volcanic eruption scenarios, we studied the distance for the range of the impacts by VEIs. To compare the results by each volcanic eruption scenario, we set the location of the vent on the 8-direction flank of the outer rim and on the center of the caldera, the internal friction angle of the pyroclastic density currents as $35^{\circ}$, the bed friction angle as $16^{\circ}$. We set the pile height of column collapse and the vent diameter with various VEIs. We properly assumed the height of the column collapse, the diameter of the vent, the initial rates of the column collapse and the simulation period, based on the VEIs, gravity and the volume of the collapsed volcanic ash. According to the comparative analysis of the simulation results based on the increase of the eruption, the higher VEI by the increase of eruption products, the farther the pyroclastic density currents disperse. To the northwest from the vent on the northeast slope of the outer rim of the caldera, the impact range was 3.3 km, 4.6 km, 13.2 km, 24.0 km, 50.2 km, 83.4 km or more from VEI=2 to VEI=7, respectively. Once the database has been fully constructed, it can be used as a very important material in terms of disaster prevention and emergency management, which aim to minimize human and material damages in the vicinity of Mt. Baekdu when its eruption causes the pyroclastic density currents to occur.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.181-191
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• 2016

We estimate the eruption history and magmatic eruptive volumes of each rock units to evaluate the volcanic eruption scale and volcanic hazard of the Ulleung Island. Especially, Maljandeung Tuff represents about 19~5.6 ka B.P. from $^{14}C$ dating, and Albong Trachyandesite, about 0.005 Ma from K-Ar dating in recent age dating data. These ages reveal evidences of volcanic activities within the last 10,000 years, indicating that the Ulleung Island can classify as an active volcano with possibility of volcanic eruption near future. Accumulated DRE-corrected eruptive volume is calculated at $40.80km^3$, within only the island. The calculated volumes of each units are $3.71km^3$ in Sataegam Tuff, and $0.10km^3$ in Maljandeung Tuff but $12.39km^3$ in accounting the distal and medial part extended into southwestern Japan. Volcanic explosivity indices range 1 to 6, estimating from the volumes of each pyroclastic deposits. The colossal explosivity indices are 5 in Sataegam Tuff, and 6 in Maljandeung Tuff in accounting the distal and medial part. Therefore, it is necessary for appropriate researches regarding possibility of volcanic eruption of the island, and establishment system of the evaluation and preparation for volcanic hazard based on the researches is required.

• Korean Journal of Remote Sensing
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• v.29 no.5
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• pp.443-459
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• 2013

Located on Java subduction zone, Merapi volcano is an active stratovolcano with a volcanic activity cycle of 1-5 years. Merapi's eruptions were relatively small with VEI 1-3. However, the most recent eruption occurred in 2010 was quite violent with VEI 4 and 386 people were killed. In this study, we have attempted to study the characteristics of Merapi's eruptions during 18 years using optical Landsat images. We have collected a total of 55 Landsat images acquired from July 6, 1994 to September 1, 2012 to identify pyroclastic flows and their temporal changes from false color images. To extract areal extents of pyroclastic flows, we have performed supervised classification after atmospheric correction by using COST model. As a result, the extracted dimensions of pyroclastic flows are nearly identical to the CVP monthly reports. We have converted the thermal band of Landsat TM and ETM+ to the surface temperature using NASA empirical formula and calculated time-series of the mean surface temperature in the area of peak temperature surrounding the crater. The mean surface temperature around the crater repeatedly showed the tendency to rapidly rise before eruptions and cool down after eruptions. Although Landsat satellite images had some limitations due to weather conditions, these images were useful tool to observe the precursor changes in surface temperature before eruptions and map the pyroclastic flow deposits after eruptions at Merapi volcano.

• The Journal of the Petrological Society of Korea
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• v.22 no.4
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• pp.273-289
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• 2013

Fallout ash is a notorious hazard that can have a variety of damages on agriculture and infrastructure and, most notably to aviation and human health. This study discusses the design of a conceptual model to aid in modeling the dispersal and deposition of ash from Mt. Baekdu volcano. It includes a discussion of assumptions and boundary conditions of the model as well as a detailed diagram of the conceptual model, complete with input parameters, units and equations. The two main processes contained within the model are the dispersal and deposition of ash, the outputs obtained from running the model, if designed, would be the total amount of fine ash contained in the eruption column, distance travelled by ash and ash thickness at surface.

• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.251-263
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• 2005

Modern volcanoes, Laoheishan and Huoshaoshan, have erupted during $1720\~1721$ in the Wudalianchi volcanic group, NE china. They comprise scoria and spatter cones that consist of potassium-rich phono-tephritic pyroclastic deposits and lavas, and include wide lava flow fields. The Laoheishan scoria cone is a polygenetic multiple volcano that overlaps earlier and later edifices with more complicated internal structures produced in greater scale and in earlier time than the Huoshaoshan. There is a funnel-shaped crater in the center of the later edifice of the Laoheishan scoria cone. The Huoshaoshan spatter cone is a monogenetic simple volcano with a central pit crater. The volcanic sequences indicate eruption processes that followed a repeated pattern that progressed through 5 stages of explosive and effusive eruption including lava fountains and Strombolian eruptions in the Laoheishan, and a recognizable pattern of 2 stages that started with Strombolian eruption and progressed through lava effusion in the Huoshaoshan.