Econ. Environ. Geol. 2012; 45(6): 685-695

Published online December 31, 2012

© THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY

A Study on Detailed Bathymetry and Geophysical Characteristics of the Summit of the Dokdo Volcano

Chang Hwan Kim1*, Chan Hong Park2, Myoung Hoon Lee1, Soon Young Choi1 and Hyeong Tae Jou3

1Dokdo research center, East Sea Research Institute, Korea institute of Ocean Science and Technology, Uljin, Korea
2East Sea Research Institute, Korea institute of Ocean Science and Technology, Uljin, Korea
3Maritime Security Research Center, Korea institute of Ocean Science and Technology, Ansan, Korea

Correspondence to :

Chang Hwan Kim

kimch@kiost.ac

Received: September 27, 2012; Accepted: December 20, 2012

Abstract

We studied the detailed bathymetry and the geophysical characteristics of the summit of the Dokdo volcano using mutibeam echosounding and geophysical survey data. The bathymetry around the main east and west islets of the Dokdo volcano shows very shallow within about 10 m water depth. From near islets to about 30 m b.s.l., the shallow water area has very steep slope and many irregular sunken rocks. The area from about 30 m to about 80 m b.s.l. shows gentle rises and falls, and less steep slope. The area from 80 m b.s.l. has gradually flat undulation and smooth slope seabaed and is extended to offshore. The main islets of the Dokdo volcano and the rocky sea bottom elongated from the islets might be the residual part of the eroded and collapsed main crater of the Dokdo volcano. The bathymetry and the seafloor image(from backscattering) data show small craters, assumed to be formed by the eruption of later volcanism. The seafloor images propose that, except some areas with shallow sand sedimentary deposits, there are typical rocky bottom such as rocky protrusions and lack of sediments in the main morphology of the survey area. The stepped slopes of the seabed are deduced to be submarine terraces. The several prominent submarine terraces are found at the summit of the Dokdo volcano, suggesting repetition of sea level changes(transgressions and regressions) in the Quaternary. The results of the magnetic anomaly and the analytic signal have a good coherence with other geophysical consequences regarding to the location of the residual crater.

Keywords bathymetry, Dokdo, crater, submarine terrace, sea level change

Article

Econ. Environ. Geol. 2012; 45(6): 685-695

Published online December 31, 2012

Copyright © THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY.

A Study on Detailed Bathymetry and Geophysical Characteristics of the Summit of the Dokdo Volcano

Chang Hwan Kim1*, Chan Hong Park2, Myoung Hoon Lee1, Soon Young Choi1 and Hyeong Tae Jou3

1Dokdo research center, East Sea Research Institute, Korea institute of Ocean Science and Technology, Uljin, Korea
2East Sea Research Institute, Korea institute of Ocean Science and Technology, Uljin, Korea
3Maritime Security Research Center, Korea institute of Ocean Science and Technology, Ansan, Korea

Correspondence to:

Chang Hwan Kim

kimch@kiost.ac

Received: September 27, 2012; Accepted: December 20, 2012

Abstract

We studied the detailed bathymetry and the geophysical characteristics of the summit of the Dokdo volcano using mutibeam echosounding and geophysical survey data. The bathymetry around the main east and west islets of the Dokdo volcano shows very shallow within about 10 m water depth. From near islets to about 30 m b.s.l., the shallow water area has very steep slope and many irregular sunken rocks. The area from about 30 m to about 80 m b.s.l. shows gentle rises and falls, and less steep slope. The area from 80 m b.s.l. has gradually flat undulation and smooth slope seabaed and is extended to offshore. The main islets of the Dokdo volcano and the rocky sea bottom elongated from the islets might be the residual part of the eroded and collapsed main crater of the Dokdo volcano. The bathymetry and the seafloor image(from backscattering) data show small craters, assumed to be formed by the eruption of later volcanism. The seafloor images propose that, except some areas with shallow sand sedimentary deposits, there are typical rocky bottom such as rocky protrusions and lack of sediments in the main morphology of the survey area. The stepped slopes of the seabed are deduced to be submarine terraces. The several prominent submarine terraces are found at the summit of the Dokdo volcano, suggesting repetition of sea level changes(transgressions and regressions) in the Quaternary. The results of the magnetic anomaly and the analytic signal have a good coherence with other geophysical consequences regarding to the location of the residual crater.

Keywords bathymetry, Dokdo, crater, submarine terrace, sea level change

    KSEEG
    Jun 30, 2024 Vol.57 No.3, pp. 281~352

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