• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.64-71
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• 2007

The hypothetical earthquake located on the fault zone along the western coast of Japan, where sufficient time has elapsed since the last earthquake or an earthquake has not occurred yet, is known to possess significant potential energy. The possibility of earthquake activities occurring here in the future is high. It is expected that the resulting tsunamis will cause great damage to the East Sea coast of Korea and affect parts of the southern coast as well. In this study, tsunami that may be caused by a virtual earthquake that is expected in the hypothetical earthquake, along the western coast of Japan, will be estimated using numerical simulation. From this, the effect of the tsunami originating from the hypothetical earthquake on the southeastern coast of Korea will be evaluated by examining the water level rise due to the maximum water level rise and changing time, for each point along the southeastern coast. It will be possible to use the virtual results obtained like this as important basic materials in future disaster prevention plans and designs, for determining the direction of coastal development, for arranging seashore and harbor structures and to carry out wave resistant design for the southeastern coast of Korea.

• Journal of the Korean Society of Food Culture
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• v.1 no.3
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• pp.279-294
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• 1986

In order to survey the traditional salt production at the eastern coast, Young-Hae, in Yi-dynasty, data of salt production were collected through interviewing with whom had received the skill from ancestors and analyzed the data. The results obtained were as follows. Salt-producer take the salt water containing much salt and then he transported the salt-water by having water buckets an back in with using the water-toting device (Mul ji ge). Finally he carried out the irrigation (Mul dae gi) to a ditch (Dorang). It is noteworthy that the East-sea salt production method was not selecting a method of salt-pond style with a bank for salt production but using the salt water transportation fashion without a bank for that. Judging from these facts, we could conclude that traditional salt production method was handed down into the Yi-dynasty from ancient times.

• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.305-311
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• 2020

Rising sea levels along the coast from global warming causes the increase of wave energy along the coast. This rise in sea levels results in relatively deep water levels, which would incur the loss of sand that had not occurred in the past from erosion in coastal areas. Generally, it has been challenging to protect against coastal erosion, and the slope, cross-sectional shape, and materials are selected for the site conditions depending on the change in external forces. However, the application of counter measures based on insufficient understanding of the phenomenon is causing various damage, indicating the need for technological development and converging technologies to improve credibility. In this study, we developed eco-friendly permeable biopolymer concrete blocks to control the coastal erosion by using the Bio-Coast, an effective porous structure that mitigates the destructive erosion caused by the rising sea levels. The hexagonal design of Bio-Coast was derived from the honeycomb, columnar joints, and clover, which are durable and stable structures in nature, and the design was changed to apply bumps on the Bio-Coast filling in the form of a clover to reduce wave overtopping and run-up. Applying the field condition of beaches on the east coast of Korea, the block weight and size were decided and the prototype blocks were manufactured and are ready for field placement. In particular, it is intended to protect coastal areas from destructive erosion by natural and artificial external forces, and to extend the design to river,s lakes, and natural walking trails, to improve the efficiency of quality control and process control through the use of blocks.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.157-168
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• 2000

Sea urchin S. intermedius occurring in the Korean east coast is a cold water species that belongs to the family Strongylocentrotidae of Echinoidea. Although it is known that there are nine species in the family, species identification criteria, phylogenetic relationships, time and process of evolution of the family members have not been uncovered clearly. In the present study, I tried to find some clues to such problems for S. intermedius by means of DNA sequences. For this, cytochrome c oxidase subunit I (COI), one of the mitochondrial genes that evolve fast and follow maternal inheritance was analyzed. DNA was extracted from the female gonad of S. intermedius, a segment of COI gene amplified by polymerase chain reaction (PCR), and finally a total of 1077 base pair sequence of COI obtained by cloning and sequencing the PCR product. The sequence was compared with homologous genes of other sea urchins and echinoderm species. Phylogenetic trees of the COI gene segment revealed that S. intenedius is a sister species of S. purpuratus which lives along the east coast of the Paciflc. With reference to the fossil records of sea urchins and genetic distances in the molecular phylogenies, it is estimated that the two species were separated about 0.89 million years ago when the earth temperature fluctuated significantly. The current disjunct distribution patterns of the two species and the climate change of the earth at the time of separation suggest that speciation might have occurred by vicariance. The COI gene sequence obtained here now can be used as a molecular character which discerns S. intermedius from the other sea urchin species of Strongylocentrotidae.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.4
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• pp.217-224
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• 2010

This study was carried out to quantify potential effects of the surrounding ocean on the observed air temperature at coastal weather stations in the Korean Peninsula. Daily maximum and minimum temperature data for 2001-2009 were collected from 66 Korea Meteorological Administration (KMA) stations and the monthly averages were calculated for further analyses. Monthly data from 27 inland sites were used to generate a gridded temperature surface for the whole Peninsula based on an inverse distance weighting and the local temperature at the remaining 39 sites were estimated by recent techniques in geospatial climatology which are widely used in correction of small - scale climate controls like cold air drainage, urban heat island, topography as well as elevation. Deviations from the observed temperature were regarded as the 'apparent' sea effect and showed a quasi-logarithmic relationship with the distance of each site from the nearest coastline. Potential effects of the sea on daily temperature might exceed $6.0^{\circ}C$ cooling in summer and $6.5^{\circ}C$ warming in winter according to this relationship. We classified 25 sites within the 10 km distance from the nearest coastline into 'coastal sites' and the remaining 15 'fringe sites'. When the average deviations of the fringe sites ($0.5^{\circ}C$ for daily maximum and $1.0^{\circ}C$ for daily minimum temperature) were used as the 'noise' and subtracted from the 'apparent' sea effects of the coastal sites, maximum cooling effects of the sea were identified as $1.5^{\circ}C$ on the west coast and $3.0^{\circ}C$ on the east and the south coast in summer months. The warming effects of the sea in winter ranged from $1.0^{\circ}C$ on the west and $3.5^{\circ}C$ on the south and east coasts.

• Journal of the Korean earth science society
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• v.31 no.5
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• pp.475-487
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• 2010

Sea surface wind field was retrieved from high-resolution SIR-C SAR data by using CMOD algorithms off the east coast of Korea. In order to extract wind direction information from SAR data, a two-dimensional spectral analysis method was applied to the normalized radar cross section of the image. An $180^{\circ}$-ambiguity problem in the determination of wind direction was solved by selecting a direction nearest to the wind vector of the ECMWF reanalysis data. Comparison of the wind retrieval patterns with the ECMWF and NCEP/NCAR dataset showed RMS errors in the range of 1.30 to $1.72\;ms^{-1}$. In contrast, comparison of wind directions revealed large errors of greater than $60^{\circ}$, which is enormously higher than the permitted limit of about $20^{\circ}$ for satellite scatterometer winds. Compared with wind speed results from different algorithms, wind vectors based on commonly-used CMOD4 algorithm showed good agreement with those derived by other algorithms such as CMOD_IFR2 and CMOD5, particularly at medium winds from 4 to $8\;ms^{-1}$. However, apparent discrepancy appeared at low winds (< $4\;ms^{-1}$). This study also addressed an importance of accurate wind direction data to improve the accuracy of wind speed retrieval and discussed potential causes of wind retrieval errors from SAR data.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.215-220
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• 1974

The sand-eel, Ammedytes Personatus is a commercially important fish abounantly found in west and east coast of Korea. Samples were collected from the Baegryeong Island (Yellow Sea), Geoje Island(southern coast) and Jumunjin (East Sea) from May 1973 to December 1974. In this paper the author dealt with some biological point of the fish, especially the relationship between total length ang body weight, and the major spawning season and sex ratio. 1. The major spawning season was confined to the end of November and the end of December at Jumunjin. 2. The sex ratio (male/female) is 0.75 before the main spawning season and increases up to 1.36 after spawning at Jumunjin in 1974. 3. The relationship between the total length (L) and body weight (In were represented as follows: $W=0.0001906L^{3.1998319}$ for the sample from Baegryeong Is. $W=0.0003419L^{3.0213438}$ for the sample from Geoje Is. $W=0.0002655L^{3.1408629}$ for the sample from Jumunjin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.362-366
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• 2007

This study determined the heavy metal contents in fish from the Korean coast of the East Sea (Donghae). The sample were divided into three parts (meat, liver, skin) and digested with acids. Then, contents of lead, cadmium, mercury, and arsenic were analyzed using atomic absorption spectrophotometry. The heavy metal contents in different parts of the fish were as follows: lead of 0.019-0.346 mg/kg (meat), 0.461-0.516 mg/kg (liver), 0.018-0.855 mg/kg (skin); cadmium of ${\leq}0.049\;mg/kg$ (meat), ${\leq}1.224\;mg/kg$ (liver), ${\leq}0.019\;mg/kg$ (skin); mercury of $1.018-2.751\;{\mu}g/kg$ (meat), $3.057-7.023\;{\mu}g/kg$ (liver), $1.068-3.940\;{\mu}g/kg$ (skin); arsenic of $0.938-25.935\;{\mu}g/kg$ (meat), ${\leq}21.082\;{\mu}g/kg$ (liver), ${\leq}3.708\;{\mu}g/kg$ (skin). Contents of heavy metals in the liver and skin from some fish exceeded the maximum CODEX guideline levels, although the contents in meat from all of the fish tested were much lower than the CODEX levels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.542-548
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• 2018

We investigated the effects of Na-alginates's average molecular weight (AMW), their concentrations and divalent metal ions on hydrophobic interaction of solution of Na-alginates in sea tangle produced Saccharina japonicus in East Coast of Korea. As the AMWs of Na-alginates decreased, the formations rates of hydrophobic micro domains and pre-micelles between intermoleculars of Na-alginates were increased. The pre-micelles between Na-alginates chains fully were formed when their concentrations reached 0.2%. In the effects of $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ on the hydrophobicity of Na-alginates solution, when the AMWs of Na-alginates were increased, the formation rates of hydrophobic micro domains produced by $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ in alginates chains were increased. When $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ concentrations that were needed to form gels of alginates solutions were insufficient, the formations of pre-micelle in alginates having large AMW were more incomplete than those of small AMW. In the increasing range from 0.01 to 0.1 mM in divalent metal ion concentration, the formation rate of pre-micelle in alginates solution added $Ca^{{+}{+}}$ were more faster than that of $Mg^{{+}{+}}$.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.5
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• pp.304-314
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• 2015

We have reviewed the current status of coastal vulnerability index(CVI) to be guided into an appropriate CVI development for Korean coast and applied a methodology into the east coast of Korea to quantify coastal vulnerability by future sea_level rise. The CVIs reviewed includes USGS CVI, sea_level rise CVI, compound CVI, and multi scale CVI. The USGS CVI, expressed into the external forcing of sea_level rise, wave and tide, and adaptive capacity of morphology, erosion and slope, is adopted here for CVI quantification. The range of CVI is 1.826~22.361 with a mean of 7.085 for present condition and increases into 2.887~30.619 with a mean of 12.361 for the year of 2100(1 m sea_level rise). The index "VERY HIGH" is currently 8.57% of the coast and occupies 35.56% in 2100. The pattern of CVI change by sea_level rise is different to different local areas, and Gangneung, Yangyang and Goseong show the highest increase. The land use pattern in the "VERY HIGH" index is dominated by both human system of housing complex, road, cropland, etc, and natural system of sand, wetland, forestry, etc., which suggests existing land utilization should be reframed in the era of climate change. Though CVI approach is highly efficient to deal with a large set of climate scenarios entailed in climate impact assessment due to uncertainties, we also propose three_level assessment for the application of CVI methodology in the site specific adaptation such as first screening assessment by CVI, second scoping assessment by impact model, and final risk quantification with the result of impact model.