• 제목/요약/키워드: southeastern region

검색결과 157건 처리시간 0.027초

Spatial distribution of vegetation along the environmental gradient on the coastal cliff and plateau of Janggi peninsula (Homigot), southeastern Korea

  • Jung, Song Hie;Kim, A Reum;Lim, Bong Soon;Seol, Jae Won;Lee, Chang Seok
    • Journal of Ecology and Environment
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    • 제43권2호
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    • pp.117-128
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    • 2019
  • Background: Cliffs are a major plant habitat around the coastal area, but in contrast to sand dunes and salt marshes, they have been little investigated in Korea. There are simple descriptions of cliff vegetation in studies on island vegetation, but there is no published paper, which addressed sea cliff vegetation synthetically. Furthermore, the coastal area where this study was carried out was designated as a conservation reserve. Even though, this area is exposed to intense recreational use such as trekking in these days. This study aims to clarify spatial distribution and structure of vegetation along the environmental gradient on coastal cliff and plateau in the Janggi peninsula (Homigot) located on southeastern Korea. Further, this study has also another objective to prepare a restoration plan to protect this conservation reserve from intense human disturbance. Results: Landscape elements were arranged in the order of sea cliff risen directly on the sea, seashore, coastal cliff, and plateau covered with relatively deep soil in a coastal area of the Janggi peninsula (Homigot), southeastern Korea. Vegetation was sampled at 59 plots arranged from the sea cliff through the seashore and coastal cliff to plateau. The sea cliff, seashore, and coastal cliff, which compose the coastal landscape, were dominated by the seashore spatulate aster (Aster spathulifolius Maxim.) community, dwarf sand sedge (Carex pumila Thunb.) community, and seashore spatulate aster (Aster spathulifolius Maxim.) community. On the plateau corresponding to the ridge of the coastal cliff, black pine (Pinus thunbergii Parl.) community, golden rain tree (Koelreuteria paniculata Laxmann) community, east Asian hackberry (Celtis sinensis Pers.) community, sawleaf zelkova (Zelkova serrata Makino) community, and Korean oak (Quercus dentata Thunb.) community were established in the mentioned order along distance from the sea. Stand ordination showed a vegetation sequence from the seashore through the cliff to the plateau, consistent in its overall pattern among sites. This was dominated by topography. There is evidence for the importance also of salinity, drought and of soil depth. Conclusion: The lack of scientific interest in cliffs to date is in striking contrast to the commonness of cliffs around the whole national territory and to the attraction cliffs have had for humans throughout history. Cliffs provide a unique habitat, rarely investigated from an ecological viewpoint. Cliffs may represent an invaluable type of ecosystem, consisting of some of the least disturbed habitats on earth and contributing more to the biodiversity of a region than their surface coverage would indicate. Although this coastal area where this study was carried out was designated as a conservation reserve, this area is in danger of severe disturbance due to excessive recreational use. We recommended a restoration plan to protect this area from such a disturbance.

해양 탄성파 탐사 결과로 본 한반도 남동부연안 4기 단층의 분포와 특성 (Distribution and characteristics of Quaternary faults in the coastal area of the southeastern Korean Peninsula: Results from a marine seismic survey)

  • 김한준;주형태;홍종국;박건태;남상헌;조현무
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2002년도 정기총회 및 제4회 특별심포지움
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    • pp.46-66
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    • 2002
  • 스파커와 12채널 스트리머, 그리고 휴대용 기록기를 이용하여 고리원전 연안에서 탄성파탐사를 수행함으로써 4기 단층의 분포와 특성을 파악하였다. 스트리머의 채널간격은 6.25 m이며 스파커는 500 Hz까지의 음파를 발생시키므로 수평 및 수직분해능이 매우 높은 자료를 얻을 수 있었다. 조사지역에는 한반도의 동남부 해안을 따라 분포하는 mud belt를 구성하는 홀로세 퇴적물이 30-40 m의 두께로 쌓여 있다. 조사지역 전체에서 홀로세와 플라이스토세의 경계를 이루는 반사면은 매우 뚜렷하며 천부가스층의 분포도 확인되었다. 조사지역내에서 다수의 4기 단층들이 발견되는데 이들은 수직에 가까운 경사를 가지며 남북방향으로 연장되고 있다. 이들 단층들은 수백 m의 간격으로 배열되어 있으며 지역적으로 인장력에 의해 형성된 특성을 보여주기도 하지만 대체로 압축력이 우세한 영역에서 형성된 것으로 해석된다. 홀로세 전기동안 해침과 관련된 침식충진 퇴적층으로 해석되는 지층을 자르는 단층들도 지역적으로 발견되었다. Mud belt를 구성하는 퇴적층 내에 분포하는 천부가스는 균열이 생긴 단층면을 따라 올라온 것 같은 양상을 보여주기도 한다. 동해를 형성시킨 지구조 운동이 마이오세 후기 이후 약해졌지만 그 이후에 한반도의 남동연안에서 단층운동이 활발하였음은 아직도 정상보다 뜨거운 맨틀영역에 속하는 이 지역이 지체구조적으로 안정되지 못함을 지시한다.

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한국 남동 대륙붕 후 제4기 퇴적층의 시퀀스 층서 (Sequence Stratigraphy of Late Quaternary Deposits in the Southeastern Continental Shelf, Korea)

  • 유동근;이치원;최진용;박수철;최진혁
    • 한국해양학회지:바다
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    • 제8권4호
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    • pp.369-379
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    • 2003
  • 한국 남동해역 대륙붕에서 취득된 고해상 탄성파 탐사자료와 퇴적물 시료의 분석에 의하면 후 제4기 퇴적층은 마지막 빙하기 이후의 해수면 변화에 의해 조절되는 저해수면계열, 해침계열, 고해수면계열로 구성된다. 시퀀스 경계면 위의 저해수면계열(층서단위 I)은 마지막 빙하기 동안 퇴적된 니질사 혹은 사질니 퇴적물로 구성되며 대륙붕단과 해곡의 외해역에 분포한다. 해침면과 최대해침면 사이에 위치하는 해침계열(층서단위 II)은 지난 15,000-6,000년 사이에 퇴적되었으며 주로 사질퇴적물로 구성된다. 해침계열은 연구해역 전반에 걸쳐 넓게 분포하지만 저해수면계열과 고해수면계열에 비해 박층으로 분포한다. 이러한 해침계열은 분포특성에 따라 3개의 소퇴적단위로 세분된다. 즉, 대륙붕단의 초기해침계열(Unit IIa), 중간대륙붕의 중기해침계열 (Unit IIb), 내대륙붕의 후기해침계열 (Unit IIc) 등으로 이들은 후배열층서의 특성을 가진다. 최대해침면 상부에 놓이는 고해수면계열(층서단위 III)은 해수면이 현수준에 도달한 지난 약 6,000년 이후에 퇴적된 현생 니질퇴적물로 구성되며 내대륙붕의 연안을 따라 제한적으로 분포한다.

한반도 남동부 포항-울산지역 심부 지질구조 분석을 위한 중력장 해석 (Gravity Field Interpretation for the Deep Geological Structure Analysis in Pohang-Ulsan, Southeastern Korean Peninsula)

  • 손유진;최승찬;유인창
    • 자원환경지질
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    • 제53권5호
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    • pp.597-608
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    • 2020
  • 규모 5 이상의 경주지진과 포항지진이 발생한 이후에도 한반도 남동부에서는 여전히 수백 건의 여진과 미소 지진이 발생하고 있다. 이러한 현상은 응력이 계속 작용하고 있다는 것을 의미하며, 또 다른 큰 지진이 발생할 수도 있음을 암시한다. 따라서 본 연구에서는 한반도 남동부 포항-울산지역의 심부 지질구조를 분석하기 위해 중력장 해석 방법을 사용하였다. 먼저 연구지역의 부족한 중력 데이터를 수집하기 위해, 중력 탐사를 시행하여 기존 자료보다 정밀한 부게 중력이상을 계산하였다. 중력이상 데이터를 바탕으로 역산 방법인 "곡률 분석 (Curvature analysis)"과 "오일러 곱풀기 방법(Euler deconvolution method)"을 이용하여, 한반도 남동부의 심부 단층의 위치 및 방향성과 최대 깊이를 분석하였다. 그 결과, 본 연구지역에는 최소 6개의 심부 단층(C1~C6)이 존재하는 것으로 해석된다. 심부 단층선 C1은 방향성과 위치가 연일구조선과 일치하는 것으로 보아, 연일구조선이 최대 약 4000m 깊이까지 이어져 있는 것으로 해석된다. 심부 단층선 C2는 여러 개의 분절된 단층들로 이루어져 있으며, 지표의 단층들과 잘 대비된다. 심부 단층선 C3, C4와 C5는 북서-남동 방향의 울산단층과 평행한 방향성을 가지는 것으로 분석되며, 초기 백악기에 남북 방향의 응력을 받아 형성되었으나 퇴적물에 덮여 지표에 드러나지 않는 것으로 판단된다. 심부 단층선 C6는 북동-남서 방향성을 가지며, 어일분지의 동쪽 경계단층이 심부로 이어져 있는 것으로 사료된다. 분석한 심부 단층선과 미소 지진 발생 현황을 대비한 결과, 심부 단층선 C1과 2018년~2019년 동안 한반도 남동부에서 발생한 미소 지진의 분포가 대략 일치하는 것을 확인하였다. 이는 심부에 존재하는 단층과 최근 발생하는 지진이 연관이 있다는 것을 시사한다.

다중위성 및 현장관측을 이용한 동해남부 연안용승 발생 전후의 해양환경 특성 (Characteristics of Ocean Environment Before and After Coastal Upwelling in the Southeastern Part of Korean Peninsula Using an In-situ and Multi-Satellite Data)

  • 김상우;고우진;김성수;정희동;야마다게이꼬
    • 해양환경안전학회지
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    • 제16권4호
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    • pp.345-352
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    • 2010
  • 본 연구에서는 하계 냉수대 발생과 관련하여 2007년 6월과 8월의 현장 및 위성에서 관측한 NOAA 해양표면수온과 SeaWiFS 해색 영상 및 QuikScat 자료를 이용하여 동해 남부해역의 수온과 클로로필 a 농도의 단기 변동과 바람을 살펴보았다. 특히, 동한난류 해역의 수온과 Chl-a의 공간적인 분포에 주목하였다. 현장관측 자료의 분석 결과, 울산 부근의 연안용승이 발생 이전인 6월의 클로로필 a 농도의 피크는 전체 조사 정점에서 50m 층에 보였고, 8월의 그 피크는 육지에 근접한 정점 4와 5에서는 10m 그리고 그 외 정점은 30m 층에 나타났지만 정점 5를 제외하고 그 농도는 6월보다 낮게 나타났다. 결과적으로, 클로로필 a 농도의 피크는 농도 차이는 있지만 8월이 6월보다 20-40m 얕은 층에 형성되었고, 이것은 남풍계열의 바람에 의한 연안용승으로 하부층의 영양염 공급 등과 관계하는 것 같다. 위성관측 수온과 클로로필 a 농도는 음의 상관관계를 보였고, 냉수가 발생한 곳에서 클로로필 a 농도는 고농도를 나타내었다. 또한, 남풍계열의 바람에 의한 영향과 동한난류의 이안은 연안에서 발생한 냉수와 Chl-a 등을 외해로 이동시키는 역할을 하였다.

허영(許郢), 허언(許鄢) 형제명의(兄弟名醫)의 가전행적(家傳行蹟)과 의약사실(醫藥事實) (Hereditary Testimonies and Medico-historical Facts of the Eminent Brother Doctors Young Hur and Eon Hur)

  • 안상우
    • 한국한의학연구원논문집
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    • 제15권1호
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    • pp.1-11
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    • 2009
  • The eminent brother doctors Cho-Gaek Hur (Young Hur) and Cho-Sam Hur (Eon Hur) represent the medical tradition of the southeastern region of Mt. Jirisan incluiding Sancheong. This study investigated and examined their herediatary testimonies and medico-historical facts described in the literature tale, genealogy and family collection of works. At an early age after their family run away to the southern region from the harm of political struggle, they gave up taking the highest-level state examination to recruit ranking officials and set their heart on learning medicine. Their choice of medicine was the second best plan for the survival of their family and descendents from the influence of their ancestors who suffered from the party strife during the late Joseon Dynasty. The case is a good example of the deliberate action of the nobility intellectuals since the late Goryeo and early Joseon dynasties to who made attempts to have the minimum elegance and cause while securing livelihood after they have been collapsed politically. The tale of Cho-Gaek and Cho-Sam is a typical story of eminent doctors which combined reality and fiction about the persons who had outstanding medical skills. In the tale, the elder brother was good at herbal prescriptions and the younger brother was good at acupuncture, contrasting the treatment of administrative internal medicine and insertive acupuncture treatment. It shows that the prepositions for the choice of the treatment method for the public during that period were safety and fast efficacy. In their old age, they wrote a book titled Jinyangsinbang. Another Jinwoosinbang is estimated as a different kind of copy, which was a medical writing from experience that derived from the same original book as Jinyangsinbang. written by Cho-Gaek Hur and it is a valuable medical material that possesses the distinct features of the local medicine during the late Joseon Dynasty. Most of the contents are variations in application using the basis of Dongeuibogam, forming the roots of the traditional Korean medicine in Sancheong region together with the medical activities of the Hur brothers.

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Evaluation of the genetic diversity of six Chinese indigenous chickens

  • Sha, Yuzhu;Gao, Caixia;Liu, Meimei;Zhao, Shengguo
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권10호
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    • pp.1566-1572
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    • 2020
  • Objective: The extensive breeding of commercial chickens has led to a sharp decrease in the resources of many indigenous chickens, especially the indigenous chickens in the southeastern coastal region, which are on the verge of extinction, and the indigenous chickens in the northwestern region of China, which are also at risk. However, there are few reports on the evaluation of genetic diversity and conservation of genetic resources of indigenous chickens in remote areas in the Northwest of China. Methods: In the present study, the genetic diversity and phylogenetic relationship of six indigenous chickens from different regions were studied based on variation in mitochondrial DNA control region (D-loop), and the degree of introgression from commercial breeds into these chickens was determined by the amount of haplotype sharing between indigenous and commercial breeds. Results: Twenty-five polymorphic sites and 25 haplotypes were detected in 206 individuals. Principal component analysis showed that the Jingning chicken had the highest genetic diversity among the six indigenous chickens. According to the degree of introgression, the six indigenous breeds may be involved in haplotype sharing with commercial breeds, and the introgression from commercial chickens into the Haidong chicken is the most serious. Conclusion: The genetic uniqueness of indigenous chickens has been eroded, so it is necessary to consider the protection of their genetic resources. Phylogenetic analysis suggests that the six indigenous chickens have two major matrilineal origins: one from Yunnan or its surrounding areas in China and the other from the Indian subcontinent.

The Fluctuation Characteristics of the Water Mass and the Current Structure of the Southeastern Region of The East Sea

  • Lee Chung Il;Cho Kyu Dae
    • Fisheries and Aquatic Sciences
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    • 제3권2호
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    • pp.97-110
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    • 2000
  • To investigate characteristics of water masses and current structures around Noto Peninsula located in south-east coastal region of the East Sea, observation results of CREAMS (Circulations Research of the East Asian Marginal Seas) cruise and data report of oceanographic observation (Japan Meteorological Agency) in June, 1995 and 1996 were used. Water mass showing characteristics of Tsushima Warm Current (TWC) exists over the continental shelf. The depth is shallower than 200m and its width and thickness are 190km and 200m, respectively. Minimum level of dissolved oxygen occurred at the layers of maximum salinity. In the current structure, a noteworthy phenomenon is that the positions of the high-salinity water (more than 34.6 psu) match well with the distributions of the southwestward flow. In June of 1995 and June of 1996, a southwestward flow were separated into two parts along line C and line G. Current directions derived from the temperature and salinity match well with the distributions of the geostrophic currents in the vertical sections. The isothermal lines and the isohaline, which exist horizontally along the coastal area of the Japan, change abruptly at the frontal area of the Noto Peninsula, then turn toward the center of the East Sea. The dynamic depth anomalies centering around the region far northwest of the Noto Peninsula were relatively high, compared to those of other regions. The isopycnic surface (sigma-t, 25.8) existed near the surface in the central part of the East Sea, but, at the depth of 100m, the isopycnic surface was found in the coastal waters.

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1975년에 발생한 중국 해성지진이 한반도에 미친 영향 (Effects of the 1975 Haicheng Earthquake on the Korean Peninsula)

  • 추교승
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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    • pp.210-221
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    • 1998
  • In the period from the year 1500 to 1980. at least 14 large earthquake with epicenters in the northeastern China and Yellow Sea were felt or destructive in the Korean Peninsula. The most sigmificant events among them were the 1668 July 25 Tancheng earthquake of mamnitude 8.5, and the 1975 Feb. 4 Haicheng earthquake of magnitude 7.3. The Haicheng earthquake of the year 1975 in am extraordinary one among those occurred in the northeastern China in the 20th century in the sense the Shake of the event affected all over the Korean Peninsula. The tremor was felt even at the southeastern tip of the Korea and northern part of Kyushu 700km far away from the epicenter. In order to see the variation and trend of the effect of the Haicheng earthquake on the Korean Peninsula, the two data sets of the northern and southern parts of the peninsula were merged into one combined data set. The spatial variation of intensity shows smooth decrease from the value 4 of the northwestern region near the source to the value 1 of the Cheju Island and Kjushu. However, there are four regions of locally high intensity value. They are the region along downstream of Abrok(Yalu) River with intensity 5, the region around Shinpo of intensity 4, the area comprising Seoul and Chuncheon Cities of intensity 4, and Pohang-Pusan area of intensity 3. We suppose that there might be three types of possible mechanisms. The first one is concerned with the lateral inhomogeneity of velocity in the crust caused by wide distribution of relatively fractured rock. The second one is related with reflections of surface waves caused by the crestal thinning effect at border regions of the Peninsular in contact with the Ulleung Basin and the Japan Basin. The third possibility is local site effect caused by thick Tertiary or Quaternary rocks and soil layers.

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양산단층지역에 분포하는 퇴적암 및 화성암류에 대한 고자기 연구 (Palaeomagnetic Study of Sedimentary and Igneous Rocks in the Yangsan Strike-slip Fault Area, SE Korea)

  • 강희철;김인수;손문;정현정
    • 자원환경지질
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    • 제29권6호
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    • pp.753-765
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    • 1996
  • It is a well known fact that the remanent magnetization direction of the Tertiary rocks is deflected significantly clockwise (about $50^{\circ}$) in the Tertiary basins of the southeastern part of Korean peninsula. This fact has been interpreted as an evidence of north-south spreading of the East Sea (Sea of Japan) and dextral strike-slip motion of the Yangsan fault. As deflection (rotation) of remanent magnetizations is frequently reported from various regions of the world in the vicinities of strike-slip fault, such phenomena are to be expected in the Yangsan fault region also. It was the purpose of this study to clarify whether such premise is right or not. A total of 445 independently oriented core samples were collected from Cretaceous rocks of various lithology (sedimentary rocks, andesites and I-type granites) in the Yangsan fault area. In spite of through AF and thermal demagnetization experiments, no sign of remanent magnetization deflection was found. Instead, palaeomagnetic poles calculated from formation-mean ChRM directions are very similar to those of contemporary (Barremian, and late Cretaceous-Tertiary) sedimentary and plutonic rocks in the other parts of $Ky{\check{o}}ngsang$ basin as well as those of China. Therefore, possibility of tilting of granite plutons and horizontal block rotation of study area is excluded. It is also concluded that the Yangsan fault did not take any significant role in the Cenozoic tectonic evolution of southeast Korea and the East Sea region. The boundary between rotated and unrotated region of remanent magnetization is not the Yangsan fault line, but must lie further east of it.

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