• Title/Summary/Keyword: Rock cliff

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Classification by Erosion Shapes and Estimation of Sea-cliff Erosion Rates through Field Survey in Dundu-ri, Anmyeondo in Korea's Western Coast (현장 조사를 통한 안면도 둔두리 해식애의 침식율 산정 및 침식형태 분류)

  • KIM, Jang-soo;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.3
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    • pp.41-53
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    • 2013
  • This research was carried out to classify erosion shapes and sea-cliff erosion rates were estimated through periodic field survey in Dundu-ri, Anmyeondo. Based on the results of field measurements using the datum-point, the annual sea-cliff erosion rate was estimated about 25~102cm/yr by point. The erosion rate gradually increases from spring to summer, but tends to decrease slightly in autumn. Specifically, the erosion rate between June and July indicated a rather decreasing trend, but showed a sharp increase between July and September. This was attributed to erosion that proceeds more rapidly than during other periods due to severe rainstorms in summer that had a direct impact on the study area as well as storm surges caused by hurricanes. Afterwards, the sea-cliff erosion rate gradually decreased in autumn, but reflected an increasing trend again from December to January. This was attributed to the mechanical weathering that actively progresses as bed rocks on the sea-cliff undergo repeated freezing and thawing in winter. The seacliff in Dundu-ri is divided into three types according to the erosion shape. First, Type A is observed in the sea-cliff composed of the same bed rocks and hard rock stratum. Second, Type B is found in the sea-cliff with a relatively gentler slope compared to Type A, since weathering material including soil is formed on the surface of the sea-cliff consisting of the same bed rocks and hard rock stratum. Lastly, Type C is observed in the sea-cliff where hard rock stratum is mixed with soft rock stratum. In this case, the soft rock stratum slumps and erodes first by precipitation and wave energy, followed by additional slumping of the exposed hard rock stratum.

Investigations on Rock Cliff Development in Dunduri, West coast of Korea, Using Schmidt Hammer Rebound Values and OSL Chronology (슈미트해머 반발도와 OSL 연대에 기반한 둔두리 해식애의 형성과정)

  • CHOI, Kwang Hee;SEONG, Yeong Bae;CHOI, Jeong-Heon;JUNG, Pil Mo;LEE, Soo Yong
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.45-56
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    • 2013
  • Rock strength test on Dunduri cliff, Chungnam province, Korea, was performed using N-type Schmidt hammer and the depositional ages of the sediments overlying the cliff were derived using OSL dating method. The averaged R-values of the cliffs investigated here were lower than those observed from the shore platforms, but with larger scatter in the former. R-values were negatively correlated to cliff face retreat, implying that the irregularity of the coastal rock faces was closely related to lithology as the weaker rocks retreated much faster than the harder rocks. The overlying deposit of the cliff tends to be thicker at valleys and were poorly sorted with angular to subangular clasts in a matrix of silt. The OSL ages (ca. 70-77 ka) presented here were older than the previously reported exposure ages (ca. 7-30 ka) of the cliff face. Therefore, it is likely that the present sea cliff was developed by expansion of the platform which had been covered by slope deposits since the last interglacial and exposed again during the Holocene.

A Study on Shoreline Change in Hampyung Bay, Southwestern Coast of korea I. Sea-Cliff Erosion and Retreat (한국 서해 남부 함평만의 해안선 변화 연구 I. 해안절벽의 침식과 후퇴)

  • ;;;;;S-Y YANG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.7 no.3
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    • pp.148-156
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    • 2002
  • The coastline of Hampyung Bay, southwestern coast of Korea, was examined and measured in the field for the understanding of geomorphic changes and sea-cliff erosion processes. The Hampyung-Bay coastline is characterized by steep-face slope and soft soil and/or intensively weathered rock composition. Saw teeth-shaped coastline, and relict weathered basement-rock and "Island Stack" exposed on the beach surface are peculiar geomorphic features indicating active sea-cliff erosion. The coastline in the study area is continuously retreating with the following cyclic process: erosion of cliff base, gravitational landslide or mass wasting, formation of talus, and then erosion and removal of talus. In this study, sea-level rise during summer in the west coast of Korea is suggested as one of the key factors fur the removal of soil taluses and, thereby, accelerating sea-cliff erosion.f erosion.

A Study on the Historical Development Pattern of ${\ulcorner}$Dae${\lrcorner}$ In Korea, (I) - Review of the Sinjungdonggukyojisungram - ("대(臺)"양식(樣式)의 역사적(歷史的) 발달과정(發達過程)에 관(關)한 연구(硏究) (I) -신증동국여지승람(新增東國輿地勝覽) 분석(分析)을 통한 대(臺)의 개념(槪念) 분석(分析)-)

  • Ahn, Gye-Bog
    • Journal of architectural history
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    • v.2 no.2 s.4
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    • pp.26-36
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    • 1993
  • The ${\ulcorner}$Dae${\lrcorner}$ is a place where a man could commune with nature. Our ancestors, who had very interested in natural landscape, and were named to the typical rock in the nature, which they called 'Dae'. The results of a analyzed the old literature(1530 : early stage of Chosen Danasty) are as follows. 1. The distribution of Dae is differ from provinces. Gangwon-do, Kyongsang-do, Cholla-do had many of the Daes. 2. The characteristics of form were classified into five groups. 1) A type of huge flat rock, which able to sit 5-6 persons(30.2%) 2) A type of mountain peak, which unable to use but seems to use images (27%) 3) A type of cliff(25.4%) 4) A type of fantastic rock (9.5%) 5) A type of stratified rock (6.3%) 3. The behavioral characteristics of the Dae were summarized watching a scenery and strolling (유(遊)), enjoying acenery, and relaxation. 4. The site locations of Dae are various such as, hill top, on cliffs, on the mountain, around river, river side cliff or grand rocks, and so forths.

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A Case Study on the relaxation of rock blocks caused by trees in slopes (절토사면의 수목에 의한 블록이완 사례 연구)

  • Kim, Soo-Lo;Kim, Yong-Soo;Shin, Chang-Gun;Ahn, Sang-Ro
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.738-743
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    • 2006
  • Falling rocks are classed by the collapse to wide meaning. it is a kinds of earth disaster that has happen every year. Falling rocks are defined as blocks which had fallen from the cliff. It is caused by the relaxation of discontinuous structures like as a joint, a foliation, a bedding, and so on. Usually, the Relaxation of blocks from the rock face is happened by various kinds factors that are acted as a complex. Sometimes, the tree can be a factor of the weakness or relaxation of rock blocks and a cause of the falling rock.

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Geological Environments, and Deterioration States and Causes on the Carved Buddhist Triad on Rock-cliff in Sinamri, Yeongju (영주 신암리 마애삼존석불에 대한 지질환경과 훼손상태 및 원인)

  • Hwang, Sang-Koo;Lee, Sang-Jin;Kim, Jae-Ho
    • The Journal of the Petrological Society of Korea
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    • v.17 no.2
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    • pp.95-107
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    • 2008
  • The Carved Buddhist Triad on Rock-cliff in Sinarnri (Treasure No. 680) consists of biotite granodiorite, which were positively carved on fore and west planes of four subvertical cliffs by two joint sets of NE-SW and NNW-SSE directions. The cliffs are $N50^{\circ}E\;85^{\circ}SE$ in fore plane, $N25^{\circ}W\;90^{\circ}$ in west plane, $N40{\sim}50^{\circ}E\; 82{\sim}85^{\circ}NW$, back plane, $N20^{\circ}W\;75^{\circ}SW$ in east plane, which are parallel to two joint sets of NE-SW and NNW-SSE directions in geology around it. The chemical index of alteration ranges 60.3 to 62.0 from the major elements in the rock that was weathered into producing kaolin minerals from alteration of feldspars and biotite. The Buddhist image has been deteriorated into joints, brown rusts, discolorations and granular disintegrations by such deterioration causes as deformation, moisture, temperature variation and microorganic living. The moisture, which leaks from groundwater in the rock, dissolve to decompose minerals.

The Excavation and Making Storytelling of Cultural Landforms around Shincheon (stream), Guemho River in Daegu (대구 신천과 금호강 일대의 문화지형 발굴과 스토리텔링 구성)

  • JEON, Young-Gweon
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.3
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    • pp.17-30
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    • 2010
  • This paper aims to excavate and make storytelling of cultural landforms around Shincheon, Geumho river in Daegu and then to build the strategy for making its application. The main results are as follows. 1) There are main cultural landforms such as Yongdubawi(龍頭岩, river cliff), river cliff, rock shelter(岩蔭), sheeting joint landform, river cave, tor, etc. around Shincheon. 2) there are main cultural landforms such as riverine wetland, ferry, point bar, river cliff, Hwadam(畵潭, pool), Donghwacheon(stream), Mutae(無怠), Chimsan(hill), Yeonamsan(hill), Sanghwadae(river cliff), etc. around Geumho river. 3) It is necessary to excavate and restore cultural landforms around Shincheon and Geumho river for protection, Also the valuable cultural landforms should be designated as cultural assets in order to prevent damage. 4) Considering from application of cultural landforms around Shincheon, natural observation site need to be designed for experiencing culture, history and ecological environment. However, in viewpoint of application of cultural landforms around Geumho river, it is much better to plan a few of Geumho river cultural landform trails for self-guided tour.

A study on classification and spatial form of coastal landscape according to anglers -From analysis on articles of specialized magazine for fishing- (낚시 전문가에 의한 해반지형경관의 분류와 그 형태에 관한 연구 -낚시 전문잡지의 기사 분석을 통하여-)

  • 강영조
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.3
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    • pp.69-79
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    • 1995
  • The purpose of this study is to clarify the classification and the spatial form of the named coastal landforms which are collected from the specialized magazine for fishing as a collective representative. The costal landform, viewing from the fishing activity, is divided into 9 types which are Yo(sunken rock), Kaeppai(rock-ribbed coast), Jolbyeok(cliff), Koppuri(spite), Chagalmadang(shringle beach), Kanchulam(intermitent rock), Mulgol(valley sea), Kaeppul(tidal flat), Sajang(sandy coast). And the characterstics of the 9types of landform were analyzed. The results of this study will contribute to establish teory on conservation and rehabilitation of costal landscape.

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Development Case of Regional Materials for Learning of Geology Units, Primary and Middle School Science at Jaeundo (초·중등과학 지질단원의 학습을 위한 자은도의 지역화 자료 개발 사례)

  • Kim, Hai-gyoung
    • Journal of the Korean Society of Earth Science Education
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    • v.13 no.1
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    • pp.110-120
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    • 2020
  • It is generally reported that field learning and a class using regional materials motivate learning and give a positive effect on learning of geology unit, science subject. The purpose of this study is to develop and to suggest regional materials for learning of geology unit, science subject at Jaeundo. The results of this study are as follows. Regional materials were developed at three locations (namjin dockyard area, yangsan beach area and dunjang beach area) of the study area. Namjin dockyard area (A site) is composed of terrain of sea cliff, sand beach and mud flat. Sedimentary rocks, weathering phenomenon of rocks and strata of various shape are distributed in sea cliff of A site. Yangsan beach area (B site) is composed of coastal terrain as sea cliff and sand beach about 1.5km long. Sedimentary rocks and rhyolite are distributed in sea cliff of B site. Tafoni formed by weathering process of rocks are developed on sedimentary rock outcrop of B site. Dunjang beach area (C site) is composed of coastal terrain of sea cliff, sand beach about 2km long and sea stack. Stratified sedimentary rocks are distributed in sea cliff of C site. Sea stack located in near halmi island on the west side of dunjang beach area is a good sample showing erosion process of sea cave for a long time. Unique geomorphology and geology phenomena distributed in 3 sites at Jaeundo can be used as regional materials for learning of geology unit, science subject. And, Regional materials shall be used in conjunction with the text book data of geology units. These 3 sites of the study area are worth using as field learning course for elementary and middle school students.