• 제목/요약/키워드: Southeastern coast

검색결과 148건 처리시간 0.028초

한반도 동해 남부 대륙붕에 분포하는 탄산질-쇄설성분 혼합 퇴적물에 대한 연구 (Mixed Carbonate-Detrital Sediments on the Southeastern Continental Shelf of Korea)

  • 최진용
    • 한국지구과학회지
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    • 제18권6호
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    • pp.493-499
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    • 1997
  • 한반도 동해 남부 대륙붕에 분포하는 탄산질-쇄설성분 혼합 퇴적물에서 성분별 입도분석을 실시하여, 퇴적 환경 및 퇴적기작을 해석하였다. 쇄설성분은 평균입도가 중립사와 세립사 범위였으며, 분급이 양호한 단빈도 입도분포를 나타내었다. 이들 쇄설 퇴적물은 해수면이 낮았던 지난 빙하기동안 해빈 퇴적환경에서 집적되었으며, 전형적인 잔류퇴적물로 해석된다. 패각류가 우세한 탄산질 성분은 거의 파쇄된 상태이며, 표면이 심하게 풍화되었다. 이들 패각도 빙하기동안 천해환경에서 서식하였던 잔류기원 패각편으로 해석된다. 한편 입도특성은 쇄설성 성분에 비하여 다소 조립하며, 분급도는 불량하였다. 이들 패각편 탄산질 성분은 집적된 이후 지속적인 파쇄 및 분급작용에 의해 입도분포의 특징이 조절된 것으로 해석된다.

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한국남동해 저서유공충의 생물장 (Biotope Analysis of the Total Benthic Foraminiferal Assemblage off the Southeastern Coast, Korea)

  • 장순권
    • 한국해양학회지
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    • 제21권3호
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    • pp.136-145
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    • 1986
  • Kim and Han이 1972년 발표한, 한국남동해안 연안해저표면퇴적물 21점에서 살아있는 개체와 죽은 개체를 합한 저서유공충 전체군집 자료를 기초로 하여 Dice 相以係數를 구하여 非加重雙群方法(Unweighted Pair Group Method)으로 군집분석 (Cluster analysis)해서 生物場(Biotope)을 구했다. 결과는 남쪽상과 북쪽상으로 대별되며, 남쪽상은 固有相과 깊은상, 북쪽상은 沿岸相과 固有相으로세분된다. 생물장들은 연구지역에서 우세한 해류와 연관이 있어서 남쪽고유상은 對馬暖流의 영향이 뚜렷하며, 남쪽 깊은상은 남하하는 底層冷水의 영향을 받았다. 북쪽연안상은 北韓寒流의 영향이 뚜렷하며, 북쪽고유상은 북한한류와 일부 東海固有水의 영향이 있다. 위의 현상은 인구지역의 상반부에는 北上하는 東韓暖流보다 남하하는 北韓 寒流가, 바깥쪽에서는 東海固有水가 큰 영향을 미치며,이는 난류가 연구지역의 오른쪽 지역의 표면을 따라 북상하기 때문인 것으로 믿어진다.

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Estimated Advection Heat in the East/Japan Sea

  • Han, In-Seong;Kang, Yong-Q;Kim, Bok-Kee;Seong, Ki-Tack
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.165-170
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    • 2003
  • A significant surface net heat loss appears around the Kuroshio and the Tsushima Warm Current regions. The area where the surface heat loss occurs should require heat to be supplied by the current to maintain the long-term annual heat balance. Oceanic heat advection in these regions plays an important role in the heat budget. The spatial distribution of the heat supply by the Tsushima Warm Current near the surface was examined by calculating the horizontal heat supply in the surface layer of the East/Japan Sea, directly from historical sea surface temperature and current data. We have also found a simple estimation of the effective vertical scale of heat supply by the current to compensate net heat loss using the heat supplied by the current in the surface 10m layer. The heat supplied by the current for the annual heat balance was large in the Korea/Tsushima Strait and along the Japanese Coast, and was small in the northwestern part of the East/Japan Sea. The amount of heat supplied by the current was large in the northwestern part and small in the southeastern part of the East/Japan Sea. These features suggest that the heat supplied by the Tsushima Warm Current is restricted to near the surface around the northeastern part and extends to a deeper layer around the southeastern part of the East/Japan Sea.

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Overfishing and recent risk for collapse of fishery in coastal Mediterranean lagoon ecosystem (Karavasta lagoon, southeastern Adriatic sea)

  • Spase Shumka;Yukio Nagahama;Sarjmir Hoxha;Koji Asano
    • Fisheries and Aquatic Sciences
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    • 제26권4호
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    • pp.294-303
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    • 2023
  • Beside that the fish species and their sub-populations are highly important as a keystone species in the coastal and marine ecosystem, there are very few studies on their presence, distribution and temporal variations within and around the lagoon ecosystems in Albania. This paper provides an updated review on the life cycle, fishery, exploitation state and management of the main species that are subject of commercial fishing in the Karavasta lagoon, southeastern Adriatic coast of Albania. Due to the fact that lagoons represent a continuum between continental and marine aquatic ecosystems they play a crucial role in species life cycles. Further on in the circumstances of rapid utilizations and environmental changes, anomalies in salinity and temperatures, accelerated anthropogenic influences their rate of vulnerability is highly increased. Following the requirements of the Water Framework Directive, transitional water, coastal lagoons and estuaries there is a need for urgent monitoring and management approaches. The commercial species include: European eel (Anguilla anguilla), species of Family Mugilidae (Mugil cephalus, Liza ramada, Liza salienes and Chelon labrosus), Seabream (Sparus aurata), Seabass (Dincentrarchus labrax), etc. Fish productivity is oscillating from maximum value of 61.95 kg/ha is recorded in period of 1975-80 and lower value of 31 kg/ha in year 2020. Our study highlights importance of fish and fishery long-term monitoring, and contributes to understand the driving factors in productivity, migration patterns and species ecology in the vital coastal ecosystems.

제주도 동남해역의 저서어업자원 조사연구 - 음향에 의한 어업생물의 분포밀도 추정 - (Hydroacoustic Investigation of Demersal Fisheries Resources in the Southeastern Area of the Cheju Island , Korea - Acoustical Estimation of Fish Density and Distribution-)

  • 이대재;이원우
    • 수산해양기술연구
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    • 제32권3호
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    • pp.266-272
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    • 1996
  • The distribution and abundance of fish in the Cheju southeastern area was studied by the combined hydroacoustic and bottom trawl surveys in April 1994 and in July 1995, respectively. The main purpose of these investigations was to provide the basic data for this management and the biomass estimation of commercially important demersal fish stocks in this area. The hydroacoustic surveys were performed by using a 50 kHz scientific echo sounder system with a microcomputer-based echo integrator. Acoustical measurements of fish abundance and distribution were conducted along the cruise tracks of research vessel and during all trawl hauls by continuous echo sounding. The average weight-normalized target strength for demersal fish aggregations was derived from the relationship between the mean volume backscattering strength for the depth strata of trawl hauls and the weight per cubic meter of trawl catches. The geographical distribution of fish stocks in the 1994 survey area was investigated in relation to oceanographic conditions. The results obtained can be summarized as follows: 1. From the 1994 and 1995 survey data, the relationship between the mean volume backscattering strength (, dB) for the depth strata of trawl hauls and the weight (W, kg/$m^3$) per cubic meter of trawl catches was expressed by the following equation = - 32.8+ lOlog(W) The average weighted-target strength value at 50 kHz derived from this equation was .. 32.8 dB/kg. 2. In 1994 and 1995, both surveys showed a trend of decreasing fish abundance toward the southern area of the Cheju Island with high densities offish along the west coast ofth.e Tsushima Island. The highest demersal concentrations in the southern area of the CheJu Island appeared in bottom waters colder than $12^{\circ}C.$. . 3. From the results of combined bottom trawl and hydroacoustic surveys, the estunated fish densities in the southeastern area of the Cheju Island were 1.5488 x $10^-4$kg/$m^3$ in the 1994 surveyand 1.9498 x $10^-4$kg/$m^3$ in the 1995 survey, respectively.

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NOAA 위성자료에 의한 해수표면 수온분포와 Cochlodinium polykrikoides 적조 발생의 상관성 (Relationship between Sea Surface Temperature derived from NOAA Satellites and Cochlodinium polykrikoides Red Tide occurrence in Korean Coastal Waters)

  • 서영상;김정희;김학균
    • 한국환경과학회지
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    • 제9권3호
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    • pp.215-221
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    • 2000
  • The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied. The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998. The initial water temperature at C. polykrikoides bloom was about 21${\circ}C$ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21${\circ}C$ isothermal line in the East Sea. The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin. The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998. In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom. The SST at the red tides varied from 21${\circ}C$ to 25${\circ}C$; 21${\circ}C$, 23${\circ}C$, 24 and 24-25${\circ}C$ in 1995, 1996, 1997 and 1998, respectively.

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Spatial and Temporal Aspects of Phytoplankton Blooms in Complex Ecosystems Off the Korean Coast from Satellite Ocean Color Observations

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy;Chang, Kyung-Il;Moon, Jeong-Eon;Ryu, Joo-Hyung
    • Ocean Science Journal
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    • 제40권2호
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    • pp.67-78
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    • 2005
  • Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

한반도 남동부 경주시 수제리-수렴리의 해안단구와 제4기 환경변화 (Marine terrace and its implications to paleoenvironment during the Quaternary at Suje-ri - Suryum-ri of the East coast of Gyeongju, SE Korea)

  • 황상일;신재열;윤순옥
    • 한국지형학회지
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    • 제19권3호
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    • pp.97-108
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    • 2012
  • 지난 수 십 년간 해안지형 연구분야의 축적된 지식은 해안단구의 분포 특징으로부터 지반 운동에 관한 양질의 기록과 증거들을 생산할 수 있게 하였다. 본 연구에서는 한반도 남동부 경주시 양북면과 양남면 소재의 수제리-수렴리 일대의 해안단구 분포와 지형발달을 논의하였다. 연구지역 일대에는 고고위읍천면을 포함하여 해발고도 160m까지 8단의 해안단구가 체계적이고 연속적으로 발달하고 있다. 특히 최근 반복적으로 보고되고 있는 해안단구 고고위면의 존재는 동해안 일대의 해안단구 형성시기를 보다 구체적으로 논의하는 중요한 단서를 제공한다. 본 연구를 통해 확인되는 해안단구 고고위면의 구정선고도와 그 추정 시기에 의하면, 플라이스토세 중기 (약 70만년) 이후 한반도 동해안의 평균 지반운동 속도는 0.23mm/year로 확인된다. 이와 같이, 해안단구 연구 결과로부터 도출되는 지반 융기 운동의 속성과 시, 공간 특성은 복잡한 한반도 신생대 제4기 지반 운동의 본질을 이해하는 기초적 자료가 될 것이다.

한반도 동남부 신생대 지각변형의 주요 특징과 지구조적 의의 (Characteristics of the Cenozoic crustal deformation in SE Korea and their tectonic implications)

  • 손문;김종선;정혜윤;이융희;김인수
    • 한국석유지질학회지
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    • 제13권1호
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    • pp.1-16
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    • 2007
  • 한반도 동남부는 신생대 동안 지구조 환경의 변화에 따라 다중 지각변형을 겪었다. 신생대 동안의 주요 지구조 사건과 이에 따른 한반도 동남부에서 발생한 지각변형의 주요 특징들을 정리하면 다음과 같다. (1) 인도-아시아의 충돌과 태평양판의 이동방향 변화기(약 50${\sim}$43 Ma): 인도판의 충돌에 인해 동아시아 대륙이 동쪽의 태평양판쪽으로 밀려가면서 해구의 퇴각이 발생하였으며, 태평양판의 이동방향이 북북서에서 서북서방향으로 회전되었다. 그 결과 한반도 동남부에는 동서 내지 서북서-동남동방향의 인장력이 발생하였고 이로 인해 남${\sim}$북북동방향의 염기성 암맥군이 관입하였다.(48 Ma 전후). (2) 동해 화장기(약 25${\sim}$16 Ma): 남북 내지 북북서-남남동방향으로 동해가 활발히 확장됨에 따라 한반도 동쪽 해안선을 따라 우수향 전단력이 발생하였다. 이로 인해 한반도 동남부에는 북북서-남남동방향의 우수향 주향이동단층운동이 발생하였으며 단층의 우향 굴곡부 혹은 오버스텝 부분에는 당겨열림형 퇴적분지가 형성되었다. 기하 및 운동학적 특징에 따라 퇴적분지들은 평행사변형과 쐐기형 확장 분지로 나누어진다. 또한 이 시기에는 지괴가 시계방향으로 수평 회전되고 북서향으로 경동되었으며 일부 퇴적분지들은 확장 축이 동에서 서쪽으로 이동되는 전파열개 과정을 겪었다. 또한 약 17Ma경에는 이러한 지각변형을 가장 서쪽에서 규제하는 연일구조선이 우수향 주향이동단층으로 운동하기 시작하였다. (3) 일본 남서부 시계방향 회전기(약 15Ma): 필리핀해판의 북상으로 이즈-보닌 아크와 일본 남서부가 충돌해 일본 남서부의 시계방향 회전운동이 발생하였다. 이로 인해 대한해협에는 북서향 압축력이 가해졌으며 한반도 동남부에서는 응력반전으로 인해 퇴적분지의 확장이 종결되고 지괴의 융기와 국지적인 지괴의 반시계방향 수평회전운동이 발생하였다. (4) 동서방향 압축응력기(약 5Ma 이후): 태평양판의 섭입각도가 얕아지고 아무르판이 동진함으로써 한반도 동남부 특히, 울산단층 동부에 상반서향의 충상단층들이 형성되어 지괴가 융기되었으며, 최근 한반도 지진 발생의 주요 원인이 되고 있다.

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하계 한국동해안 냉수대 발생의 시공간적 분포특성 (Study on the Cold Mass Occurrence in the Eastern Coast of the Korean Peninsula in Summer)

  • 서영상;황재동
    • 한국환경과학회지
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    • 제14권10호
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    • pp.945-953
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    • 2005
  • Daily time series of longshore sea surface temperature (SST) data at 3 stations, sea surface SST data at 58 stations in the eastern coast of the Korean Peninsular from 2001 to 2005 were used in order to study the temporal and spatial variations of the upwelling coastal cold water occurred in summer season. When the cold water occurred, SST has been decreased more than $-5^{\circ}C$ in a day. The cold water occurred frequently in the eastern coastal areas of Korea such as Ulgi, Kampo, Jukbyun. Daily variations of cold water temperature were quantified using remote control buoy system at Kijang in the southeastern coastal water from July to August in 2004. Hourly variations of SST occurred around $\pm3^{\circ}C$ when cold water disappeared at Kijang. There were close relationship between the strength of East Korean Warm Current, North Korean Cold Water and the scale of spatio-temporal cold water variations in summer season.