• Title/Summary/Keyword: 분화이력

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Risk Analyses from Eruption History and Eruptive Volumes of the Volcanic Rocks in Ulleung Island, East Sea (울릉도 화산암류의 분화이력과 분출량에 따른 위험도 분석)

  • Hwang, Sang Koo;Jo, In Hwa
    • 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.

Selecting Hazardous Volcanoes that May Cause a Widespread Volcanic Ash Disaster to the Korean Peninsula (한반도에 광역화산재 재해를 발생할 수 있는 위험화산의 선정)

  • Yun, Sung-Hyo;Choi, Eun-Kyeong;Chang, Cheolwoo
    • 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.

Analysis of Global Volcanic Activity during 2018 (2018년 지구에서 분화한 화산 활동 분석)

  • Yun, Sung-Hyo;Ban, Yong-Boo;Chang, Cheolwoo
    • The Journal of the Petrological Society of Korea
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    • v.28 no.1
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    • pp.39-52
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    • 2019
  • Volcanic activity, which can read to various danger and hazards to human life, has been part of the Earth's history for a long time. There are approximately 1,520 volcanoes during the Holocene period (about 10,000 years ago) that have been active on Earth. Recently, there are about 210 volcanoes have been recorded since 2010. Meanwhile, there are 83 known active volcanoes in 2018 based on the USGS data. Approximately 80-90 volcanoes are active on Earth for over a year. More than 90% of these volcanoes are located on the circum-Pacific volcanic belt, commonly known as 'Ring of Fire'. This high number of active volcanoes within this area coincides with the distribution maps of active volcanoes on the earth: about 80% on subduction zone of the convergent plate boundaries; 15% on divergent plate boundaries and 5% on intra-plate zone. Five volcanoes are most active during the survey period of 51 weeks: 50 times in Aira (Japan), 49 times in Sabankaya (Peru), 49 times in Sheveluch (Russia), 44 times in Ebeko (Russia) and 40 times in Kirishimayama (Japan). Based on the available data about volcanic activity, there is no significant change in volcanic activity and similar levels of volcanic activity is observed every year.

On-orbit Thermal Environment Characteristic according to Launch Time of CubeSat STEP Cube Lab-II (초소형위성 STEP Cube Lab-II의 발사시간 변화에 따른 궤도 열환경 특성 분석)

  • Son, Min-Young;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.15 no.5
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    • pp.89-97
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    • 2021
  • STEP Cube Lab-II (Cube Laboratory for Space Technology Experimental Project-II) is a 6U Cube satellite equipped with optical and infrared cameras for monitoring Mt. Paektu volcanic eruption signs and earth observation in the Korean peninsula. To guarantee successful mission operation of the cube satellite in orbit, thermal design is essential for the electronic equipment, and must be kept within the allowable temperature range during the mission period. Thus, it is necessary to analyze the predictable orbital thermal environment. The STEP Cube Lab-II is launched through the KSLV-II, however, the operation orbit has not been determined due to the unknown launch time. In this study, we performed a thermal analysis of the satellite and investigated the heat flux according to launch time to analyze the worst orbital conditions that could occur.