• Title/Summary/Keyword: offshore islands

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Paleozoic Strata in the Lankawi Geopark, Malaysia: Correlation with Paleozoic Strata in the Korean Peninsula (말레이시아 랑카위 지질공원의 고생대 퇴적층: 한반도 고생대 퇴적층과의 대비)

  • Ryu, In-Chang
    • Economic and Environmental Geology
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    • v.43 no.4
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    • pp.417-427
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    • 2010
  • The Lankawi archipelago is located in 30 km western offshore near the Thailand-Malaysia border in west coast of the Malay Peninsula and consists of 99 (+5) tropical islands, covering an area of about $479km^2$. Together with biodiversity in flora and fauna, the Lankawi archipelago displays also geodiversity that includes rock diversity, landform diversity, and fossil diversity. These biodiversity and geodiversity have led to the Lankawi islands as a newly emerging hub for ecotourism in Southeast Asia. As a result, the Lankawi islands have been designated the first Global Geopark in Southeast Asia by UNESCO since July 1st, 2007. The geodiversity of Lankawi Geopark today is a result of a very long depositional history under the various sedimentological regimes and paleoenvironments during the Paleozoic, followed by tectonic and magmatic activities until the early Mesozoic, and finally by surface processes that etched to the present beautiful landscape. Paleozoic strata exposed in the Lankawi Geopark are subdivided into four formations that include the Machinchang (Cambrian), Setul (Ordovician to Early Devonian), Singa (Late Devonian to Carboniferous), and Chuping (Permian) formations in ascending order. These strata are younging to the east, but they are truncated by the Kisap Thrust in the eastern part of the islands. Top-to-the-westward transportation of the Kisap Thrust has brought the older Setul Formation (and possibly Machinchang Formation) from the east to overlay the younger Chuping and Singa formations in the central axis of the Lankawi islands. Triassic Gunung Raya Granite intruded into these sedimentary strata, and turned them partially into various types of contact metamorphic rocks that locally contain tin mineral deposits. Since Triassic, not much geologic records are known for the Lankawi islands. Tropical weathering upon rocks of the Lankawi islands might have taken place since the Early Jurassic and continues until the present. This weathering process played a very important role in producing beautiful landscapes of the Lankawi islands today.

Community Structures of Macrozoobenthos in the Subtidal Area of the Nakdong River estuary, Korea (낙동강 하구 조하대 대형저서동물의 군집구조)

  • SEO, JIN-YOUNG;KIM, JEONG-HYUN;CHOI, JIN-WOO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.21 no.3
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    • pp.112-124
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    • 2016
  • In order to see the spatio-temporal distribution patterns of macrobenthic fauna in subtidal areas of Nakdong River estuary, benthic fauna samples were collected seasonally at 8 sites in subtidal areas of Nakdong River estuary from February, 2013 to November, 2015. Sandy sediment facies was found in the southern part of the barrier islands in Nakdong River estuary while muddy sediment facies occupied at sites in offshore areas. The bottom salinity of the study area was measured greater than 30 psu during the study period. The mean species richness and density were estimated as 266 species and $859ind\;m^{-2}$, respectively. Polychaete worms were the most abundant fauna group, and four polychaete species such as Goniada maculata, Sternaspis chinensis, Magelona japonica, and Heteromastus filiformis occurred as dominant species in this study area. Pseudopolydora kempi known as an opportunistic species occurred dominantly only in August, 2013. From the multivariate analyses, the macrobenthic fauna in the subtidal area of the Nakdong River estuary could be divided into 2 assemblages that each occupied sites near barrier islands and offshore areas by sediment facies.

Characteristics of Wave Propagation by Water Level Conditions at Wando Sea Area: Numerical Modeling (완도 해역의 해수면 조건에 따른 파랑 변형 특성)

  • Jeon, Yong-Ho;Yoon, Han-Sam;Kim, Dong-Hwan;Kim, Won-Seok;Kim, Heon-Tae
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.1
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    • pp.1-11
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    • 2013
  • The aim of this study was estimated the characteristics of the wave propagation by the water level conditions using a numerical modeling method at the Wando sea area. For three cases numerical simulation on the condition of incident and incoming of the deepwater design wave and the season normal wave, the spatial distribution of the incident wave at study area were investigated. And the calculated numerical modeling results were compared with measured field wave data. According to on-site wave data measured for 18 days, the range of the significant wave height and period were 0.10~1.14 m, 4.35~8.74 sec, respectively, and the maximum wave height were 0.15~1.66 m. From the results of numerical model for offshore design wave incident, the wave height attacked from Southern-East direction at this study area were over maximum 10.5 m because of rapidly change of water depth. Numerical modeling by three water level conditions of Approxmate Lowest Low Water Level(Approx. L.L.W), Mean Sea Level(M.S.L) and Approximate Highest High Water Level(Approx. H.H.W) were practiced. From the results for the case of Approx. H.W.L, variations of wave height at the back area of islands were about 1.6 m at maximum value for the case of deepwater design wave incoming. The significant wave heights of winter season were bigger than summer under normal wave condition, the incident wave height over 5.5 m decreased by shielding effect of islands. The change of maximum wave height at summer season were distinct than winter and was about 1.2 m and 0.8 m, respectively.

An Experimental Study of Sediment Transport Patterns behind Offshore Structure (외해 구조물 배후의 표사이동에 관한 실험적 연구)

  • Shin Seung-Ho;Hong Keyyong
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.7 no.4
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    • pp.207-215
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    • 2004
  • Recently, securing a vast land in the land region becomes more difficult and efforts to seek its alternation in the sea area have been increased. As a consequence, the coastal region has been faced to extensive beach erosion problems. In planning offshore structures such as artificial islands, it is necessary to forecast the influence of the structure construction exerting on the beach erosion of the adjacent coast. In the present study, the sediment movement pattern behind offshore structure was examined through a series of three dimensional movable bed experiments, so as to develop the numerical model which forecasts morphological change including beach erosions. The experimental results reveal that the sediment movement patterns of the beach line side and the depth region are separated at a certain boundary line. In details, at the beach side including swash zone the sediment movement becomes dominant, which is governed by a relation between depth contours and incident wave directions, while at the depth region the bed load and suspended load due to the orbit motion of waves are carried by nearshore currents, and both movements are clearly separated at a specified boundary that is related to partial standing wave from the beach. It is expected that these results can be effectively used for verification of a numerical model on morphological change of the coast.

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The Strategies of Busan Port Related to the Opening of Yangsan Port (양산항 개장에 따른 부산항의 대응전략)

  • Lee, Soo-Lyong;Moon, Seong-Cheol;Choi, Chul-Jin;Bae, Byung-Tae
    • Journal of Korea Port Economic Association
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    • v.23 no.2
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    • pp.1-24
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    • 2007
  • With its foreign trade rapidly expanding and with economic growth continuing at a substantial rate, China has become the largest container traffic generating country in the world. And with trend of container ships becoming larger and faster, the environment surrounding ports in North-East Asia are rapidly changing. The Yangsan, offshore port for Shanghai, being developed on the islands of Da Yangsan and Xiao Yangsan, some 30km offshore, and connected to the mainland by the six-lane highway Donghai bridge, opened phase one in late 2005 and phase two in 2006 respectively and will have 29 berths by 2012 and be able to handle 15 million TEU. The Port of Shanghai which passed Busan in terms of container volume further consolidated its position as the world's No. 3 port with an annual volume of 21.7 million TEU in 2006 and is likely to have emerged as the biggest container port in the world. The Port of Busan, the world's fifth largest container port, wants to survive as regional hub port. In this circumstance, the strategies of the Port of Busan should be established.

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Design and Performance Evaluation of the Savonius Tidal Current Turbine (항력식 조류발전 터빈의 최적 형상 설계 및 유동 수치해석을 통한 성능 평가)

  • Jo, Chul-Hee;Ko, Kwang-Oh;Lee, Jun-Ho;Lee, Kang-Hee
    • New & Renewable Energy
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    • v.8 no.2
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    • pp.6-13
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    • 2012
  • Due to global warming, the need to secure an alternative resource has become more important nationally. Having very strong current on the west coast with up to 10 m tidal range, there are many suitable site for the application of TCP (Tidal Current Power) in Korea. On the south west regions between many islands that create strong current in the narrow channels. The rotor is one of the essential components which can convert tidal current energy into rotational energy to generate electricity. The design optimization of rotor is very important to maximize the power production. The performance of rotor can be determined by various parameters including number of blades, shape, sectional size, diameters and etc. This paper introduces the multi-layer vertical axis tidal current power system which can be applied to offshore jetties and piers effectively. Various cases of VAT turbine were designed. Specifically, the number of blades and turbine shape are changed in several cases. Also, performance analysis was carried out by CFD.

A Study on the Development of a Wide-Area Monitoring and Control System for Tug/barges

  • Moon, Serng-Bae;Kim, Bo-Kyung;Jeong, Tae-Gweon
    • Journal of Navigation and Port Research
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    • v.33 no.9
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    • pp.609-614
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    • 2009
  • The traffic of tug/barges which are carrying construction materials, large plants for harbor development, or offshore structures has recently increased in the coast of Korea. The west and south coast of Korea are always congested due to a lot of islands and traffic concentration. Specially tug/barges have higher probability of marine accidents due to their bad maneuverability than others. Considering the operational circumstance and maneuverability, this study was to develop a wide-area monitoring and control system for tug/barges in the coastal area of Korea. The system was made in the form of three program modules i.e. navigation analysis program module, monitoring and control program module, database module. And seven functions were programmed to monitor and control the tug/barges efficiently. These are ship information search, tug/barge information and track management, designated area and safe navigation zone management, fairway management, accident data management, warning of danger, safety information management.

A Practical Application of Multiple Wave Models to the Small Fishery Harbor Entrance

  • Jung, Jae-Hyun;Lee, Joong-Woo;Jeon, Min-Su;Kang, Seok-Jin
    • Journal of Navigation and Port Research
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    • v.31 no.7
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    • pp.579-587
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    • 2007
  • Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

Distribution And Abundance Of Copepods In The Gulf Of Alaska And The Bering Sea In Summer 1978 (하계(夏季) Alaska만(灣)과 Bering해(海)의 Copepods의 분포조성(分布組成))

  • Lee, Sam Seuk
    • 한국해양학회지
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    • v.15 no.1
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    • pp.17-33
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    • 1980
  • The materials were obtained in the eastern Gulf of Alaska and the south- eastern Bering Sea during the cruise of the research vessel, Ohdae San, from July to October 1978. A total of 76 samples were taken by NORPAC net from a depth of 200 meters or less in coastal areas. 1. The surface water temperature in the coastal waters, varing from 9 to 10$^{\circ}C$, was lower than that in offshore waters which varied from 10 to 12.9$^{\circ}C$ in the eastern Gulf of Alaska. Thermocline was formed in the 30∼50 meter layer. Salinity of the coastal waters of Kenai Peninsula and Kodiak was 30 which was slightly lower than that of offshore. 2. The water temperature of the surface layer down to 30 meters varied from 7 to 10$^{\circ}C$ and from 1 to 9$^{\circ}C$ in the layer below 30 meters in the south-eastern Bering Sea. Meandering thermal front spread from the Alaska Peninsula to St. Matthew Island by way of St. Paul, and a thermocline was found at the 30∼50 meter layer Salinity ranged from 31.0 to 33.0 and that of northern and coastal waters was little lower than that of offshore. 3. Zooplankton biomass fluctuated from 0.1 to 23.6cc/10㎥ in the eastern Gulf of Alaska and 2.0 to 26.1cc/10㎥ in the south-eastern Bering Sea. Plankton was rich in the following areas, the inshore Kodiak waters, the northern Bering Sea, the Coastal waters and waters adjacent to Alutian islands however, poor in the central Bering Sea. In general, the south-eastern Bering Sea has a higher concentration of plankton volume than the eastern Gulf of Alaska. 4. Twenty three species representing 17 genera of copepods were identified from the samples. These were mostly composed of the cold water species, such as Pseudocalanus minutus, Acartia longiremis, Metridia lucens and Eucalanus bungii var. bungii. 5. The cold oceanic species were composed of Calanus cristatus, C.plumchrus, Metridia lucens, Eucalanus bungii var. bungii and Scolecithricella minor. The cold neritic species were Centropages abdominalis, Pseudocalanus minutus, Acartia longiremis, Eurytemora herdmanii, Pontella pulvinata, P. longipedata and Tortanus discaudatus. On the other hand, the warm oceanic species were Calanus tenuicornis and Oithona plumifera. The cosmopolitan species were Calanus finmarchicus and Oithona similis. 6. It was suggested that the cold oceanic species, Eucalanus bungii var. bungii and Metridia lucens in the south-eastern Bering Sea can be recommended as a valuable indicator species for finding the fishing grounds of demersal fish such as pollock and yellowfin sole in this area.

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Analysis of Built and Walking Environment for Coastal Ferry Terminal using IPA -Focusing on Yeosu Coastal Ferry Terminal- (IPA를 이용한 연안여객터미널의 시설 및 보행특성 분석 -여수연안여객터미널을 중심으로-)

  • Song, Tea-Han;Kim, Hwa-Young
    • Journal of Korea Port Economic Association
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    • v.37 no.3
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    • pp.93-104
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    • 2021
  • A coastal ferries, which serve as a mode between mainland and offshore islands, are frequently used by islanders and travelers visiting islands. Therefore, it is located in a place with good accessibility to the downtown so that users can use it conveniently. However, research on the built environment and walking environment of coastal ferry terminals has not been conducted to ensure that elderly islanders and general travelers can use comfortably the coastal ferry terminal. In this study, with a focus on the coastal ferry terminal space, the walking section was set as 1)the accessibility of the coastal ferry terminal, 2)the built environment for using the coastal ferry terminal, and 3)walking environment in the ferry boarding and disembarkation at the coastal ferry terminal, and 4, 5)walking environment in the ferry. An evaluation tool was developed to measure the walking environment for each walking section, and the importance and satisfaction of users were analyzed using the IPA for the Yeosu Coastal Ferry Terminal. As a result, in the process of approaching the ferry terminal, 'convenience of using public transportation by foot' and 'convenience of using signposts guiding the location and direction of the ferry terminal' were investigated as concentrated areas. On the other hand, the built environment inside the ferry terminal and the walking environment showed that the satisfaction of the users was high. Regarding the walking environment from the ferry terminal to the ferry, the 'surface walking environment of the walking path', 'convenience of walking with luggage', 'convenience of walking in the slope section', and 'convenience of walking in the ferry ramp section' showed low satisfaction. This study can be used as basic data for improving the facilities and walking environment of Yeosu Coastal Ferry Terminal and is expected to be used as data for comparative research with other coastal ferry terminals.