• Title/Summary/Keyword: 해안단구

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Development of the GIS Method for Extracting a Specific Geomorphic Surface of Coastal Terrace at Gampo Area, Southeastern Coast in Korea (GIS를 이용한 해안단구 지형면 분류 기법 연구 - 감포지역을 사례로 -)

  • 박한산;윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.36 no.4
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    • pp.458-473
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    • 2001
  • The classified map of geomorphic surfaces is the most basic data for the geomorphological research. Up to recent days, the traditional methods extracting specific geomorphic surfaces are accomplished by analyzing the aerial photographs and topographical maps, and field works. Also it needs a lot of time and expertness. Furthermore it is difficult to gain the aerial photographs in Korea. Since digital maps in Korean Peninsula are almost completed recently, we tried to extract specific surfaces by analyzing the characteristics of marine terraces based on the level of paleoshoreline and slope analysis on the terrace surface using GIS. However, research used GIS was hardly found up to date, therefore many problems are not be solved yet. The aim of this study is to develop the more efficient and objective method for the extraction and classification of specific geomorphic surfaces by using GIS in Gampo-eup, Gyeongju city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was Gyeongiu city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was suitable for classification of specific geomorphic surface, and presented method of setting up optimum criteria of extraction. As last, effectiveness and problems of these methods were investigated through conincidence rate and error rate.

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The Geomorphic Development of River Terraces along the Middle and the Lower Parts of the Osip-cheon River in Samchok City (三陟 五十川 중.하류부의 河岸段丘 지형발달)

  • 윤순옥;황상일;정석교
    • Journal of the Korean Geographical Society
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    • v.37 no.3
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    • pp.222-236
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    • 2002
  • The Osip-cheon river flowing on the east side of the Taeback mts. has formed river terraces on the several heights along the middle- and downstream. The river terraces are classified into 5 climatic ones and 7 thalassostatic ones. The thalassostatic ones are found to the height of 145-l50m level at 20-30m intervals. These vertical distribution is caused by the continuous uplift and periodical rise and fall of the sea-level. The high higher surfaces among the thalassostatic ones are the highest among those of Korea. The chronologies of the terraces are correlated to the marine oxygen isotope stages : The thalassostatic terraces on the level of 40 m.a.s.l. are to the stage 7, 70 m.a.s.l.. to the stage 9, 90 m.a.s.l. to the stage 9, 110 m.a.s.1. to the stage 11 and those of 150 m.a.s.1. to the stage 15 among the Interglacial Ages. The landuses and geomorphic landscapes of the Samchok area are chracteristic, because the karst landforms, such as doline and uvala, are developed on the surfaces of the middle-, the higher- and the high higher surfaces of river terrace.

Estimation of Uplift Rate Based on Morphostratigraphy and Chronology of Coastal Terraces in the SE Part of Korean Peninsula (한반도 남동부에 분포하는 해안단구의 지형층서 및 연대자료를 이용한 융기율 평가)

  • Kim, Ju-Yong;Yang, Dong-Yoon;Choi, Won-Hak;Kim, Jeong-Chan
    • The Korean Journal of Quaternary Research
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    • v.20 no.2
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    • pp.51-57
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    • 2006
  • Terrace stratigraphy of the southeastern coastal areas of Korea is reappraised on the basis of terrace mapping and geochronology. Coastal terraces are divided into uHT ($90{\sim}130\;m$), HT ($63{\sim}86m$), MT ($36{\sim}55\;m$), and LT ($8{\sim}25\;m$) according to altitude. Among these, the Lower Terrace I is interpreted to have formed during MIS 5e based on Tephras Aso-4 (MIS 5c), Ata(MIS 5d or 5e) and OSL data. The age of Lower Terrace II is thought to be MIS 5a based on tephras and OSL data. The uplift rate in the SE part of Korea during the formation of the Lower Terrace (i.e. the MIS 5) ranges from 0.08 to 0.25 mm/yr and averages as 0.15 mm/yr. Such value is quite small in comparison to that of Japan, Taiwan or many other tectonically active areas in the world.

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The characteristics of quaternary fault and coastal terrace around Suryumri area. (수렴리 일대에 발달하는 신기단층 및 해안단구의 층서 고찰)

  • 이병주;감주용;양동윤;정혜정
    • The Journal of Engineering Geology
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    • v.10 no.2
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    • pp.133-149
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    • 2000
  • The study area which contains the coastal terrace of the southeastern part of Korean peninsula, well developed the lineaments which are NNE, NE and WNW directions. The area crops out Cretaceous sedimentary rocks and granite porphyry, Tertiary conglomerate, tuffite and basalt and Quarternary deposits. Coastal terraces are subdivided into low, middle and upper terraces(LT, MT, UT) based on the topographic levels. Terrace gravels are deposited on these wave-cut erosional surface during the initial lowering stage of sea level fluctuation. Terrace gravels are typified by granule to pebble layers with slightly inclined beddings. These gravels are interpreted as beach gravels belonging to berm or swash zone based on the present distribution of beach gravels. The Suryum fault is characterized by the thrust which is gradationally changing the strike from ENE to NNE. The extension of the fault is about 200m and Maximum displacement is about 1.5m.

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Revisiting the OSL Ages of Marine Terrace Sediments at Suryum Fault Site, Gyeongju, South Korea: Single Grain OSL Dating (수렴단층노두 해안단구 퇴적층의 OSL 연대에 대한 재고찰: 단일입자 OSL 연대측정 연구)

  • Heo, Seoyoung;Choi, Jeong-Heon;Hong, Duk-Geun
    • The Journal of the Petrological Society of Korea
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    • v.23 no.3
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    • pp.187-195
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    • 2014
  • In this paper, we report new OSL ages of the marine terrace sediments at Suryum fault site, using single grains of quartz, and briefly discuss their chronological implications on the timing of terrace formation along the southeastern coast of Korea. Of 1200 grains measured, 93 quartz grains were found to have OSL properties suitable for dating, the equivalent dose ($D_e$) values of which varied significantly, ranging from 50 Gy to 610 Gy with the overdispersion of $30{\pm}4%$. Applied to the Central Age Model (CAM) and Minimum Age Model (MAM), these quartz grains showed the OSL ages of $83{\pm}4ka$ and $60^{+3}{_{-7}}ka$, respectively, both of which are stratigraphically inconsistent with the previously reported OSL ages of lower $2^{nd}$ terrace (MIS 5a; ~80 ka). However, Finite Mixture Model (FMM) revealed that a small fraction of the measured quartz grains ($6{\pm}4%$) were of the ages ($194{\pm}24ka$) corresponding to MIS 7. Conclusively, based on single grain OSL ages, it would be prudent not to exclude the possibility that the marine terrace sediments at Suryum fault site have formed during MIS 7. Further, our single grain OSL ages imply that multiple grain(single aliquot) OSL dating methods are not applicable to the marine sediments at Suryum fault site.

Quaternary Geology of the Conjunction Area of the Yeongsan and Sampo rivers (영산강 하류와 삼포강 합류부 일대 제4기 지질 연구)

  • Kim, Ju-Yong;Yang, Dong-Yoon;Hong, Sei-Sun;Nahm, Wook-Hyun;Lee, Heon-Jong;Lee, Jin-Young;Kim, Jin-Kwan;Oh, Keun-Chang
    • The Korean Journal of Quaternary Research
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    • v.19 no.1
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    • pp.1-17
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    • 2005
  • This study aims to study the distribution and formation age of Quaternary deposits in the downstream of Yeongsan Estuarine River, encompassing Muan, Illo and Donggang counties. For this purpose the authors examine several borehole data, and step trench survey for excellent profiles was studied in connection with grain size population and magnetic susceptibility. As a result, it is interpreted that the coastal plain of the Yeongsan River was formed by sea level rise after Last Glacial Maximum(LGM). The fore edge/escarpment of coastal terraces distributed 7-10 m asl is assumed to be formed during the last glacial period, while the coastal terraces distributed above 7-10m asl formed during MIS 5a. In addition, the fore edge/escarpment of coastal terraces distributed above 15 m asl is presumed to be have been formed during the stadial of last interglacial period, while the formation age of coastal terraces distributed above 15m(asl) is assumed to be MIS 5e. This formation age can be estimated by the coastal terrace ages of the southeastern coast of Korean Peninsula. The characteristics of Quaternary deposits linked to paleolithic culture will eventually lead to the reconstruction of ecosystem environment of paleolithic peoples.

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