• Title/Summary/Keyword: 평형 해안선

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A Preliminary Geomorphic Overview of Late Quaternary Glacier Fluctuations in the South Shetland Islands, West Antarctica (서남극 남쉐틀랜드 군도의 제4기 후기 빙하 활동의 지형학적 고찰)

  • Lim, Hyoun-Soo;Yoon, Ho-Il;Lee, Yong-Il;Kim, Yea-Dong;Owen Lewis A.;Seong, Yeong-Bae
    • Journal of the Korean Geographical Society
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    • v.41 no.5 s.116
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    • pp.513-526
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    • 2006
  • The timing and extent of glaciations during the Late Quaternary in the South Shetland Islands, West Antarctica were defined using field mapping, geomorphic analysis and radiocarbon dating. Landforms of glacial erosion and deposition, in particular subglacial meltwater channel erosion, suggest that at least three glaciations occurred during the late Quaternary within the study region. During the global LGM, glacial troughs (such as Maxwell Bay and Admiralty Bay) were overdeepened by an ice stream moving south from $an\sim1000m-thick$ ice cap centered on the present-day continental shelf to the north. This ice was responsible for the subglacial meltwater channel erosion, and glacial polished and striated bedrock on the Fildes Peninsula. The recent local glaciations occurred about 2,000 years ago and during Little Ice Age (LIA). During these glaciations, glaciers were less extensive than the previous one and less erosive as a cold-based ice

Hydraulic Characteristics Investigation due to the Change of GapWidth between Artificial Reefs (인공리프 개구폭 변화에 따른 흐름특성 고찰)

  • Kim, Kyu-Han;Shim, Kyu-Tae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.6
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    • pp.408-415
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    • 2016
  • Small fishing ports and coastal structures installed in a relatively low sea water depth disturb the wave induced current and cause the collapse of equilibrium state of sediment transport. These structures creates diffracted waves and matter the concentration of waves to cause the beach erosion. In order to mitigate these eroding problems on the beach, many counter measurements were proposed such as detached breakwater, groin or headland; however, these methods interrupt the aesthetic view of sandy beach due to the exposed structures above the sea level and have difficulty of applying to those beaches with the good scenery. Furthermore, some of these methods create secondary environmental problems after the installations. To eliminate these problems, one of the countermeasures, artificial reefs have been selected and used worldwide to minimize the disturbance of the scenery and secondary effects on the environment. Meanwhile, it is important to set the design elements for installing the artificial reefs such as that of length, opening width, clearing distances from the shoreline and more. Nevertheless, there are no construction manuals or standards for designing the artificial reefs with these important design elements yet. In this study, different conditions of artificial reefs were used with various cases throughout hydraulic model test to precisely analyze the changes of waves and currents to propose the standards of design elements to install the artificial reefs.