• Title/Summary/Keyword: Korean east coast

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Study on Coastal Terrace and Uplift Rate in the West and South Coasts of South Korea (서해안 및 남해안의 해안단구 연구와 융기율)

  • Park, Chung-Sun;Kihm, You Hong;Nahm, Wook-Hyun;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.4
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    • pp.49-62
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    • 2018
  • This study tries to reveal uplift rates inferred from relative and absolute ages on coastal terrace in the West and South Coasts of South Korea. Uplift rate from relative ages on Pleistocene coastal terrace in the West Coast rangesfrom approximately 0.059 to 0.282 m/ky, while a range of approximately 0.020~0.385 m/ky is calculated from the South Coast, suggesting that the South Coast shows higher rate than the West Coast. Based on absolute ages on coastal terrace during MIS 5 in the South Coast, on the other hand, the uplift rates 1 and 4 have ranges of approximately 0.042~0.062 m/ky and 0.051~0.087 m/ky, respectively, indicating that uplift rate in the South Coast is one-third to one-fourth to that in the East Coast. No research on absolute ages in West Coast terrace and lack of relative and absolute ages in the West and South Coasts are considered as the limit in this study.

Propagation Characteristics of Potential Tsunamis near Ryukyu Islands (유구열도 주변 잠재 지진해일 전파특성)

  • Bae, Jae-Seok;Choi, Jun-Woo;Yoon, Sung-Bum
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.451-454
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    • 2008
  • Potential tsunamis which may occur near Ryukyu Islands were simulated. Propagation characteristics of the potential tsunamis over the southwestern sea and the influence of tsunamis on the southwestern coast of Korean Peninsula were analyzed. The shallow water area in the east sea of China and the deep water Okinawa Trough play an important role in wave transformation and propagation of the potential tsunamis. The propagation characteristics of the potential tsunamis generated near Ryukyu Islands can be described as in followings : In the first stage after generation, the tsunamis propagate with high speed both northeastward and southwestward along the Okinawa Trough. As a result the waves are elongated and the tsunami height is significantly reduced. The elongated crest of tsunamis spans the whole distance of the Okinawa Trough and lines up toward the edge of the continental shelf of East China Sea. Then, the tsunamis are propagating towards the southeast coast of China. Thus, the influence of tsunamis on the Korean coasts becomes weak.

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Wave and surface current measurement with HF radar in the central east coast of Korea (동해중부에서 HF Radar를 이용한 파랑 및 해수유동 관측)

  • Kim, Moo-Hong;Kim, Gyung-Soo;Kim, Hyeon-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.6
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    • pp.771-780
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    • 2014
  • We installed HF Radar of Array type in Site A and Site B, observing the real-time wave and current in the central East coast of Korea. WERA(WavE RAdar) in this research uses HF Radar of Array Type with frequency range of 24.525 MHz, developed by Helzel, Germany. Each site is a 8-Channel system consisting of four transmitters and eight receivers, generating wave and current data, being observed every thirty minutes at the present time. HF Radar has grid resolution of an interval of 1.5 km using bandwidth of 150 kHz; The wave data covers an observation range of about 25 km, and the current data covers the maximum observation range of about 50 km. The Wave data observed by HF Radar was compared and verified with the AWAC data observed in the research sites. MIT also compared the Current data observed by HF Radar with Monthly the East sea average surface current and current flow pattern provided by KOHA(Korea Hydrographic and oceanographic Administration). The regression line and deviation of the comparison data of Wave was calculated by Principal Component Analysis, which showed correlation coefficient 0.86 and RMSD 0.186. Besides, data analysis of long-term changes of the current in the East coast showed that, during August and September, the North Korean Cold Current flow into the southward direction and the East Korean Warm Current flow into the northward direction in the coast.

The prediction of maximum wave height for virtual tsunami in the eastern coast of the Korea (가상 지진해일에 의한 동해안에서의 피해 예측)

  • Sim, Ju-Yeol;Choi, Moon-Kyu;Cho, Yong-Sik
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.229-232
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    • 2008
  • The Central East Sea Tsunami caused huge damage to the eastern coast of the Korean Peninsula, eapecially Imwon port was damaged relatively strongly beacause of water depth variation which makes the wave concentration on this port. there are many virtual tsunami in east sea which has a possibility of happening. So, it is very important to expect the region which may be damaged by vritual tsunmis. In this study, modified dispersion-correction terms are used. The modified scheme has the advantage of using the constant spatial grid size and time step size even in real topography. Dynamic linking technique and staggered grid system are used. Using this model some cases of virtual tsunami was simulated and check the region which is occured maximum wave heights on the eastern sea of the Korean peninsula.

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Analysis of Regional Effects of the Seasonal Management Policy on Coal-fired Power Plant Using Difference-in-difference Method (이중차분법을 이용한 석탄화력발전소에 대한 미세먼지 계절관리제의 지역별 효과 분석)

  • Kang, Heecha
    • Environmental and Resource Economics Review
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    • v.31 no.3
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    • pp.343-365
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    • 2022
  • This paper tries to identify the effect of reducing PM2.5 concentration of the First Seasonal Management Policy implemented by Korean government by using statistical method. In particular, this paper tests the hypothesis that this policy effect may differ by region (west-coast, south-coast, and east-coast). To this end, this paper analyzed only pure policy effects by removing temporal abnormalities such as COVID-19, warm winter temperature during the policy implementation period (December 2019 to March 2020) by using the difference-in-difference method (DID). As a result of the analysis, this policy had the effect of reducing PM2.5, but the effect is not homogenous by region. In particular, PM2.5 reducing effect is the largest in west-coast region and south-coast region folllows, but its effect is not statistically significant in the east-cost region. In conclusion, this paper drew implications that the current Seasonal mamangement policy which is implemented regardless of the regional difference needs to be changed.

Analysis of Tsunami Resonance and Impact in Coastal Waters

  • Lee, Joong-Woo;Kim, Kyu-Kwang;Yamazaki, Yoshiki;Cheung, Kwok Fai;Yamanaka, Ryoichi
    • Journal of Navigation and Port Research
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    • v.35 no.9
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    • pp.755-763
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    • 2011
  • Recently, extreme tsunami waves generated by submarine earthquake have caused tremendous damages to the coastal cities and ports. Strong seiche oscillations and runups are observed in specific sea areas around the world. Although no frequent impacts to the coast of Korean peninsula, there exist some important events in the east of Korea in the past. This study focuses on two historical events and recalculate with different fault and rupture mechanism for prediction considering the recent trend of submarine earthquake. The present study of the 1983 Akita tsunamis demonstrates the multi-scale resonance along continental coasts. Together with the Nankai tsunami for inland sea, we have confirmed the inland sea resonance surrounded by islands in defining the impact along the coast. Coherence and wavelet analyses for deducing a predominant period and time frequency are useful in reasoning the inundation. The resonance modes, which are largely independent of the tsunami source, allow identification of at-risk communities and infrastructure for mitigation of tsunami hazards. Furthermore, understanding of the resonance and the predicted runups for the site of power plant and industrial complex in the east coast of Korea would allow better preparation for the future disasters.

A Study of the Optimal Deployment of Tsunami Observation Instruments in Korea (지진해일 조기탐지를 위한 한국의 지진해일 관측장비 최적 위치 제안 연구)

  • Lee, Eunju;Jung, Taehwa;Kim, Ji-Chang;Shin, Sungwon
    • Journal of Ocean Engineering and Technology
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    • v.33 no.6
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    • pp.607-614
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    • 2019
  • It has been an issue among researchers that the tsunamis that occurred on the west coast of Japan in 1983 and 1993 damaged the coastal cities on the east coast of Korea. In order to predict and reduce the damage to the Korean Peninsula effectively, it is necessary to install offshore tsunami observation instruments as part of the system for the early detection of tsunamis. The purpose of this study is to recommend the optimal deployment of tsunami observation instruments in terms of the higher probability of tsunami detection with the minimum equipment and the maximum evacuation and warning time according to the current situation in Korea. In order to propose the optimal location of the tsunami observation equipment, this study will analyze the tsunami propagation phenomena on the east sea by considering the potential tsunami scenario on the west coast of Japan through numerical modeling using the COrnell Multi-grid COupled Tsunami (COMCOT) model. Based on the results of the numerical model, this study suggested the optimal deployment of Korea's offshore tsunami observation instruments on the northeast side of Ulleung Island.

Tongue-like Warm Water Appeared in the East Entrance of the Jeju Strait (제주해협 동쪽 입구에 출현하는 설상의 난수)

  • RHO Hong Kil;HIRANO Toshiyuki
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.299-304
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    • 1983
  • A tongue-like warm water which is a part of the Tsushima Warm Current appears whole year around in the east entrance of the Jeju Strait. Because of this warm water, the current direction flowing into the Jeju Strait from its west area seems to be changed in the Jeju Strait. Therefore the intermediate and bottom water of the Jeju Strait may greatly influence the formation of the coastal water in the South Coast of Korea. Since this tongue-like warm water is stronger in winter than in summer in its formation, Tsushima Warm Current comes closer to the South Coast of Korea in winter and its north boundary frequently approaches close to the coast of Geomun Island and Sori Island.

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The Vision and Tasks of Area Coast Guard (지방해양경찰청 시대의 비전과 과제)

  • Lee, Eun-Bang
    • Proceedings of KOSOMES biannual meeting
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    • 2006.05a
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    • pp.225-230
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    • 2006
  • On the analysis of the regional organizations of coast guards in USA, Japan and BK, the ideal organization of area coast guard of Korea is proposed. It is composed of three area coast guards in West, South and East sea and special units in order to carry out missions and to response requirements and needs in the maritime fields in object oriented way. The proposed regional organization can be actualized as the model of development by improving the listed tasks.

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