• 제목/요약/키워드: Eastern Sea

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Ancient Seaports on the Eastern Coast of India: The Hub of the Maritime Silk Route Network

  • DAYALAN, DURAISWAMY
    • Acta Via Serica
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    • 제4권1호
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    • pp.25-69
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    • 2019
  • India has occupied the most important position of sea trade in the entire South Asian region since the beginning of maritime trade. The extensive maritime trade network between the Harappan and Mesopotamian civilizations as early as the $3^{rd}$ millennium BCE is testimony to the long maritime trade history of India. The Harappans constructed many seaports including the first high-tide dockyard in the world for berthing and servicing ships at the port town of Lothal, Gujarat. From the dawn of the historical epoch, the maritime trade network of India expanded extensively. The long 5422.6 kms coastline of the Indian mainland (excluding the coastlines of the Andaman and Nicobar islands and the Lakshwadweep Islands) is well known for its several seaports manly located at river mouths or outlets to the sea. The main objective of this paper is to discuss in detail all the major ancient seaports on the eastern coast of India and their maritime trade activities. The narrative of these ports is based on archaeological explorations and excavations, foreigners' accounts, Indian literary sources, inscriptions, archival materials, and the field study and personal observation of the author.

Modification of Sea Water Temperature by Wind Driven Current in the Mountainous Coastal Sea

  • Choi, Hyo;Kim, Jin-Yun
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.177-184
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    • 2003
  • Numerical simulation on marine wind and sea surface elevation was carried out using both three-dimensional hydrostatic and non-hydrostatic models and a simple oceanic model from 0900 LST, August 13 to 0900 LST, August 15, 1995. As daytime easterly meso-scale sea-breeze from the eastern sea penetrates Kangnung city in the center part as basin and goes up along the slope of Mt. Taegullyang in the west, it confronts synoptic-scale westerly wind blowing over the top of the mountain at the mid of the eastern slope and then the resultant wind produces an upper level westerly return flow toward the East Sea. In a narrow band of weak surface wind within 10km of the coastal sea, wind stress is generally small, less than l${\times}$10E-2 Pa and it reaches 2 ${\times}$ 10E-2 Pa to the 35 km. Positive wind stress curl of 15 $\times$ 10E-5Pa $m^{-1}$ still exists in the same band and corresponds to the ascent of 70 em from the sea level. This is due to the generation of northerly wind driven current with a speed of 11 m $S^{-1}$ along the coast under the influence of south-easterly wind and makes an intrusion of warm waters from the southern sea into the northern coast, such as the East Korea Warm Current. On the other hand, even if nighttime downslope windstorm of 14m/s associated with both mountain wind and land-breeze produces the development of internal gravity waves with a hydraulic jump motion of air near the coastal inland surface, the surface wind in the coastal sea is relatively moderate south-westerly wind, resulting in moderate wind stress. Negative wind stress curl in the coast causes the subsidence of the sea surface of 15 em along the coast and south-westerly coastal surface wind drives alongshore south-easterly wind driven current, opposite to the daytime one. Then, it causes the intrusion of cold waters like the North Korea Cold Current in the northern coastal sea into the narrow band of the southern coastal sea. However, the band of positive wind stress curl at the distance of 30km away from the coast toward further offshore area can also cause the uprising of sea waters and the intrusion of warm waters from the southern sea toward the northern sea (northerly wind driven current), resulting in a counter-clockwise wind driven current. These clockwise and counter-clockwise currents much induce the formation of low clouds containing fog and drizzle in the coastal region.

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프랙탈 내삽함수 역산법을 이용한 홀로세 해수면의 내삽 및 재구성 (Interpolation and Reconstruction of the Holocene Sea-levels Using Inverse Fractal Interpolation functions)

  • 정상용;김대철;이희일
    • 한국해양학회지
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    • 제29권3호
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    • pp.228-238
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    • 1994
  • 제4기 동안에 일어난 해수면 변화는 지역적 그리고 나아가 전 지구 기후변화에 좋 은 지시자가 되고 있다. 세계 해수면은 제 4기 동안 매우 불규칙하게 변해왔는데 여기 에 대한 정밀한 수학적 접근은 어려운 실정이었다. 이 연구에서 처음으로 세계 해수면 변동자료에 확율 프랙탈을 적용하여 제4기 해수면 변동을 재구성 하였다. 미국 대서양 연안에 위치한 허드슨만과 델라웨어 해안의 홀로세 해수면 변화에 대한 프랙탈 차원을 상자 계산 방법으로 측정한 결과, 허드슨만 해수면 분노는 프랙탈 차원이 1,358이고 델라웨어 해수면 변화는 1,346이다. 프랙탈 내삽함수의 역산 방법 (IFIF)의 유효성이 허드슨만과 델라웨어 해수면의 내삽에 의해서 검증되었고, IFIF에 의해서 두지역에서 의 합리적인 해수면들이 복원되었다. 델라웨어 해수면 자료는 허드슨 해수면 자료보다 IFIF의 내삽에 대해 통계적 오차가 적게 나타나는데, 이는 델라웨어 해수면 자료가 허 드슨 자료보다 더 신빙성이 높다는 것을 의미한다. IFIF는 한국 해안의 해수면을 추정 하는 데도 이용되었는데, 한국 해안의 해수면 자료는 허드슨만이나 델라웨어 지역보다 자료가 충분치 못하다. 따라서 IFIF 의 적용 통계 오차가 적은 텔라웨어 해수면 자료 에서 구한 프랙탈 차원을 사용하여 한국 해안에 대한 IFIF의 수직 비율 인자를 계산하 였다.함수(FIF)를 한국 해안과 미국 대서양 연안의 고해수면의 재구성에 적용한 결과,한국의 고해수면은 미국의 고해수면과 다른 변화를 보였다.8000년 전부터 현재까지 두지역의 해수면은 비교해 보면 한국 해수면이 미국 해수면 보다 훨씬 높았다.

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황해동부에서 4월에 관측 수온역전 (Temperature inversions observed in April in the eastern Yellow Sea)

  • 이상호
    • 한국해양학회지
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    • 제27권4호
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    • pp.259-267
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    • 1992
  • 황해동부에서 1991년 4월에 관측된 CTD자료를 분석한 결과, 해수의 직구조는 계절적 수온약층과 수온역전층에 의해 뚜렷이 구분되는 상부혼합층 및 중층저온수로 저층 고온수 삼층구조를 보여준다. 조사지역 남부에서 저층수는 중층수보다 수온이 $3^{\circ}C$ 높아 수온역전이 가장 뚜렷하다. 수온역전은 $100{\;}km{\;}{\times}{\;}100{\;}km$의 관측해역에 걸쳐 형성 되었고 약 1.5개월후에도 관측되었다. 이 저층수의 수온과 염분은 단면내 핵구조 및 남쪽에서 분쪽으로 향하는 설상분포를 보여, 조사해역 남쪽에 있는 봄철 해양전선의 해수가 북쪽으로 150 km 정도의 거리에 걸쳐 황해냉수 아래로 요입된 것을 제시한다.

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북태평양 어업의 호리존탈.매니저먼트에 관한 연구 (A Study on the Horizontal Management of the Fisheries in the Northeastern Pacific)

  • 이재후
    • 수산경영론집
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    • 제17권1호
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    • pp.41-76
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    • 1986
  • The northeastern Pacific and eastern Bering Sea supports large and divers finfish and shellfish compelxes. The North Pacific fishing grounds are largest fish production total 30.89 percent of the world in 1983. Recent action by the around countries extending their fisheies jurisdiction to 200 mile has provided a new environment. The new approch to fisheries management has resulted in an arormous expansion in tile demand for scientific information. These are no longer limited to biological concerns. Emphasis has been focused recently on the need to understand the economic, social, politics and philosophy characteristics of a fishing and how they will be affected by management decisions. The horizontal management and portfolio management for fisheries has increased interest in complex biological models and the coupling of these models with economic, politics and phyisophy components. Successful completion of this task will require and expanded understanding of oceanographic, biological, economic, social, politics and philosophic process associated with fisheries. Particular attention should be devoted to acquiring information an data processing for Korean trawl fishery, stock assessment in the areas. The need for international collaboration in management must be stressed. Some northeast Pacific and eastern Bering Sea fish stock migrate over long distances and political boundaries. Further, nearly all the fish stocks are harvested by several nations. The features require cooperation and coordination of research activities. The horizontal management will be made a way these activities for the around countries in the sea. Strongly, tile proposed again, Pacific International Council for Exploration of the Seas, PICES will interest between all users of the area's fisheries.

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Surface Current Fields in the Eastern East China Sea

  • Lie, Heung-Jae;Cho, Cheol-Ho
    • Journal of the korean society of oceanography
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    • 제32권1호
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    • pp.1-7
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    • 1997
  • Surface current fields in the eastern East China Sea (ECS) were constructed by analyzing trajectories of 58 satellite-tracked surface drifters released during 1991-1996. Composite trajectories and 20-minute-by-20-minute box-averaged current vectors show that the basic current pattern composes of: the Kuroshio main stream, which turns eastward toward the Tokara Strait; a northward branch current of the Kuroshio on the ECS outer shelf deeper than 100 m; and an anticyclonic circulation in the northern Okinawa Trough west of Kyushu. The northward branch current sharply changes its direction to the northeast when it crosses a line connecting Cheju Island, Korea and Goto Islands, Japan. The basic pattern of current field changes slightly from winter to summer, and the main axis of the Tsushima Current in the Korea Strait is found to shift seasonally. The drifter experiment does not support the claim that the Yellow Sea Warm Current is separated from the northward branch current on the outer shelf southeast of Cheju Island. We suggest that the use of the term 'Tsushima Current' be limited to the northeast channel flow in the Korea Strait. The new term 'Kuroshio Branch Current' is suggested for the northward branch current on the outer shelf south of Cheju-do, which is separated from the Kuroshio.

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한국 연안 표층수온의 경년변동과 장기변화 (Interannual Variability and Long-term Trend of Coastal Sea Surface Temperature in Korea)

  • 민홍식;김철호
    • Ocean and Polar Research
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    • 제28권4호
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    • pp.415-423
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    • 2006
  • Interannual variation and long-term trends of coastal sea surface temperature (SST) in Korea were investigated by analyzing 27 coastal SST time series from 1969 to 2004. Long-term linear increasing trend was remarkable with the rate over $0.02^{\circ}C/year$ at almost all the stations. The slope of long-term linear trend was larger at the stations along the eastern coast than in the western and southern regions. It was also noticeable that there was a common tendency of interannual variability with the period of 3-5 years at most of the stations. SST was lower in the 1970's and early 1980's while it was higher in the 1990's and early 2000's after the increase in the late 1980's. The pattern of the interannual variability of SST was similar to that of air temperature. Increasing trend of minimum SST in winter was obvious at most stations na it was larger along the eastern coast, while the linear trend of maximum SST in summer was less definite. Therefore, the decreasing tendency of annual amplitude was mainly due to the increasing tendency of SST in winter.

저층 삼중자망에 대한 동해안산 고무꺽정이 (Dasycottus setiger)의 망목 선택성 (Mesh selectivity of the bottom trammel net for spinyhead sculpin Dasycottus setiger in the eastern coastal sea of Korea)

  • 박창두;배재현
    • 수산해양기술연구
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    • 제53권4호
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    • pp.317-326
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    • 2017
  • Comparative fishing experiments were conducted in the eastern coastal waters near Uljin, Korea from 2002 to 2004, using the experimental trammel nets to estimate the selectivity for spinyhead sculpin Dasycottus setiger. The inner panels of the nets were made of nylon monofilament with four mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) while its two outer panels were made of twisted nylon multifilament with a mesh size of 510 mm. The SELECT (Share Each Length's Catch Total) procedure with maximum likelihood method was applied to obtain a master selection curve. The different functional models (normal, lognormal, bi-normal, and logistic model) were fitted to the catch data. The lognormal model with the fixed relative fishing intensity was chosen as the best-fitted selection curve through comparison of model deviance and AIC (Akaike's Information Criterion). The optimum relative length (the ratio of fish total length to mesh size) with the maximum relative efficiency was obtained as 2.492.

Evolution of the eastern margin of Korea: constraints on the opening of the East Sea (Japan Sea)

  • Kim, Han-Joon;Jou, Hyeong-Tae;Suk, Bong-Chool
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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    • pp.73-83
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    • 2007
  • We interpreted marine seismic profiles in conjunction with swath bathymetric and magnetic data to investigate rifting to breakup processes at the eastern Korean margin that led to the separation of the southwestern Japan Arc. Analysis of rift fault patterns suggests that rifting at the Korean margin was primarily controlled by normal faulting resulting from extension rather than strike-slip deformation. Two extension directions of E-W and NW-SE for rifting are recognized. We interpret that the E-W direction represents initial rifting at the inner margin and the NW-SE direction probably represents the extension in response to tensional tectonics associated with the subduction of the Pacific Plate in the NW direction. No significant volcanism was involved in rifting. In contrast, the inception of sea floor spreading documents a pronounced volcanic phase which appears to reflect asthenospheric upwelling as well as rift-induced convection particularly in the narrow southern margin. We suggest that structural and igneous evolution of the Korean margin, although it is in a back-arc setting, can be explained by the processes occurring at the passive continental margin with magmatism influenced by asthenospheric upwelling.

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Review of the Shell-bearing Gastropods in the Russian Waters of the East Sea (Sea of Japan). IV. Heterobranchia

  • Gulbin, Vladimir V.;Chaban, Elena M.
    • 한국패류학회지
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    • 제25권1호
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    • pp.71-79
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    • 2009
  • Based on investigation of archive collections of A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and O.A. Scarlato Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. The fourth part of the Review includes 46 species of Heterobranchia (Allogastropoda, Opistobranchia, and Pulmonata). Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented.

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