• Title/Summary/Keyword: 평정해산

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The Morphological Change by Slope Erosional Processes in the Dokdo Seamount (독도해산의 사면침식으로 인한 지형변화)

  • Kang, Ji-Hyun;Sung, Hyo-Hyun;Park, Chan-Hong;Kim, Chang-Hwan;Jeong, Eui-Young
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.791-807
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    • 2008
  • The purpose of this study is to analyze landform characteristics and geomorphic processes in Dokdo seamount. For geomorphic analysis, bathymetry data were collected by multi-beam echosounder and the seismic survey was also conducted. Through the detailed analysis of depth, slope, aspect and erosional landform, Dokdo Seamount is characterized by a flat or gently sloping top of $2^{\circ}$ or less and seamount slope with $14{\sim}40^{\circ}$ gradient. There are protrusion of landform around the Dokdo on top of the Dokdo seamount. It is inferred that the features are formed by collapsed debris deposits or remained bedrocks by differential erosion in the past. The massmovement topography including slump and slide is shown on seamount slope with $14{\sim}40^{\circ}$ gradient. In addition, gullies with various length are developed on the Dokdo seamount slope. Slope erosional processes occur more actively along the submarine gullies on the Dokdo seamount. It is inferred that the massmovement processes on the slope of Dokdo seamount are related to earthquake activities and evolution of submarine volcano. Consequently, slope of the Dokdo seamount has retreated by erosional processes of mass-movement and submarine gullies.

Eruption Cycles and Volcanic Form of the Dokdo Volcano, Korea (독도 화산의 분출윤회와 화산형태)

  • 황상구;전영권
    • Economic and Environmental Geology
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    • v.36 no.6
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    • pp.527-536
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    • 2003
  • The Dokdo volcano in the south-central part of the East Sea is classified into 8 rock units. The units and sequence suggest that the Dok Island forms a small stratovolcano constructed from at least 3 times eruption cycles above the sea level and proceeded with transformation of a few different eruption styles during each cycle. Reconstruction of the volcanic form, from the geologic structures and spatial lithofacies changes, suggests that the island is remnants of the southwestern caldera rim of the stratovolcano whose central part lies several hundred meters to the northeast. The subaqueous volcano shows abig guyot, which looks like a shield volcano, that represents gentle slope at 90-175 m deep and relatively steep one in 200∼2,000m, and 25∼30km wise base on sea floor. Therefore the total Dokdo volcano represents a multiple volcano that stratovolcano with small caldera overlies the big guyot.