• Journal of the Korean Geotechnical Society
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• v.35 no.8
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• pp.43-56
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• 2019

This research has been conducted to suggest an estimation equation of compression index to be practically applied to the southeastern areas by finding out physical and mechanical characteristics of 229 points on the southeastern coast areas (Busan area: 78 points, Gimhae area: 103 points, Geoje area: 18 points, Changwon area: 30 points) through indoor tests and analyzing its relation to the compression index. From the results, we could not only find out correlation between natural water content, liquid limit and initial void ratio versus compression index for soft ground on each of the southeastern coast areas, but also an integrated correlation equation of the southeastern coast areas. In addition, we have performed a comparative analysis of the existing estimated equation of compression index and that found in this paper. As a result, the existing estimated equation suggested by foreign researchers has shown considerable error to be applied to the soft ground on the southeastern coast areas in Korea. The estimated equation of compression index with the water content out of the existing estimated equations has shown minimum 10.8% to maximum 48.1% of error rate, minimum 13.4% to maximum 288.5% of error rate with liquid limit or minimum 9.4% to maximum 211.4% of error rate with initial void ratio. On the other hand, error rates calculated with the estimated equations of compression index from this research have shown minimum 10.5% to maximum 13.4% with water content, minimum 11.6% to maximum 21.3 with liquid limit or minimum 7.1% to maximum 11.7% with initial void ratio, for better results than those with existing estimated equations. In addition, relation between compression index and expansion index has shown Cs = (1/5 ~ 1/12)Cc similar to the existing relation of Cs = (1/5 ~ 1/10)Cc.

• Economic and Environmental Geology
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• v.15 no.3
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• pp.123-154
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• 1982

Petrochemical, K-Ar dating, Sand Rb/Sr isotopes, metallogenic zoning, paleomagnetic and geotectonic studies of the Gyongsang basin were carried out to examine applicability of plate tectonics to the post-late Cretaceous igneous activity and metallogeny in the southeastern part of Korean Peninsula. The results obtained are as follows: 1. Bulgugsa granitic rocks range from granite to adamellite, whose Q-Ab-Or triangular diagram indicates that the depth and pressure at which the magma consolidated increase from coast to inland varying from 6 km, 0.5-3.3 kb in the coastal area to 17 km, 0.5-10 kb in the inland area. 2. The volcanic rocks in Gyongsang basin range from andesitic to basaltic rocks, and the basaltic rocks are generally tholeiitic in the coastal area and alkali basalt in the inland area. 3. The volcanic rocks of the area have the initial ratio of Sr^{87}/Sr^{86} varying from 0.706 to 0.707 which suggests a continental origin; the ratio of Rb/Sr changing from 0.079-0.157 in the coastal area to 0.021-0.034 in the inland area suggests that the volcanism is getting younger toward coastal side, which may indicate a retreat in stage of differentiation if they were derived from a same magma. The K_2O/SiO_2 (60%) increases from about 1.0 in the coastal area to about 3.0 in the inland area, which may suggest an increase indepth of the Benioff zone, if existed, toward inland side. 4. The K-Ar ages of volcanic rocks were measured to be 79.4 m.y. near Daegu, and 61.7 m.y. near Busan indicating a southeastward decrease in age. The ages of plutonic rocks also decrease toward the same direction with 73 m.y. near Daegu, and 58 m.y. near Busan, so that the volcanism predated the plutonism by 6 m.y. in the continental interior and 4 m.y. along the coast. Such igneous activities provide a positive evidence for an applicability of plate tectonics to this area. 5. Sulfur isotope analyses of sulfide minerals from 8 mines revealed that these deposits were genetically connected with the spacially associated ingeous rocks showing relatively narrow range of ${\delta}^{34}S$ values (-0.9‰ to +7.5‰ except for +13.3 from Mulgum Mine). A sequence of metallogenic zones from the coast to the inland is delineated to be in the order of Fe-Cu zone, Cu-Pb-Zn zone, and W-Mo zone. A few porphyry type copper deposits are found in the Fe-Cu zone. These two facts enable the sequence to be comparable with that of Andean type in South America. 6. The VGP's of Cretaceous and post Cretaceous rocks from Korea are located near the ones($71^{\circ}N$, $180^{\circ}E$ and $90^{\circ}N$, $110^{\circ}E$) obtained from continents of northern hemisphere. This suggests that the Korean peninsula has been stable tectonically since Cretaceous, belonging to the Eurasian continent. 7. Different polar wandering path between Korean peninsula and Japanese islands delineates that there has been some relative movement between them. 8. The variational feature of declination of NRM toward northwestern inland side from southeastern extremity of Korean peninsula suggests that the age of rocks becomes older toward inland side. 9. The geological structure(mainly faults) and trends of lineaments interpreted from the Landsat imagery reveal that NNE-, NWW- and NEE-trends are predominant in the decreasing order of intensity. 10. The NNE-trending structures were originated by tensional and/or compressional forces, the directions of which were parallel and perpendicular respectively to the subduction boundary of the Kula plate during about 90 m.y. B.P. The NWW-trending structures were originated as shear fractures by the same compressional forces. The NEE-trending structures are considered to be priginated as tension fractures parallel to the subduction boundary of the Kula plate during about 70 m.y. B.P. when Japanese islands had drifted toward southeast leaving the Sea of Japan behind. It was clearly demonstrated by many authors that the drifting of Japanese islands was accompanied with a rotational movement of a clock-wise direction, so that it is inferred that subduction boundary had changed from NNE- to NEE-direction. A number of facts and features mentioned above provide a suite of positive evidences enabling application of plate tectonics to the late Cretaceous-early Tertiary igneous activity and metallogeny in the area. Synthesizing these facts, an arc-trench system of continental margin-type is adopted by reconstructing paleogeographic models for the evolution of Korean peninsula and Japan islands. The models involve an extention mechanism behind the are(proto-Japan), by which proto-Japan as of northeastern continuation of Gyongsang zone has been drifted rotationally toward southeast. The zone of igneous activity has also been migrated from the inland in late-Cretaceous to the peninsula margin and southwestern Japan in Tertiary.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.175-185
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• 2020

Quantitative and qualitative surveys were conducted during scuba diving activity between May 2017 and June 2017 in order to analyze spring marine algal community structure at Gijang-gun, Busan. A total of 121 species including 13 (10.7 %) Chlorophyta, 18 (14.9 %) Phaeophyta, and 90 (74.4 %) Rhodophyta were identified. The species count in the subtidal zone (110 species) was twice as high as in the intertidal zone (56 species). In terms of regions, 88,76, and 75 species were found in Mundong, Gongsu, and Daebyeon, respectively. Mean biomass for the whole study area was 1,501.5 g·m^-2, higher for the subtidal zone (1,869.4 g·m^-2) than for the intertidal zone (1,133.5 g·m^-2). Mean biomass by region values were 2,234.0 g·m^-2, 1,228.1 g·m^-2, and 1,044.4 g·m^-2 for Mundong, Gongsu, and Daebyeon, respectively. Ulva australis, Sargassum thunbergii, and Corallina pilulifera had high biomass in the intertidal zone, while Sargassum macrocarpum, Undaria pinnatifida, and Phycodrys fimbriata had high biomass in the subtidal zone. The composition ratio of marine algal functional forms suggests that the entire study area had 'Low' status, and all sites fell within 'Low' to 'Moderate' status. Results indicate that opportunistic species are widely distributed throughout the Gijang-gun coast, hence potential effects of disturbance and environmental pollution should be considered. Seaweed farming in particular - a major activity along the Gijang-gun coast -, together with effects of other anthropogenic activities such as national fishing port development and the coastal improvement project, could have long-term effects on marine algal communities. Therefore, long-term monitoring and management plans for marine algal communities will be required.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.88-96
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• 1972

1. The present paper deals with the contents of heavy metals such as mercury, cadmium, lead and copper in 17 species of edible seaweeds collected from Jumunjin, Pohang, Pusan, Chungmu, Yeosu and Wando areas. 2. The concentration of mercury in the air-dried seaweeds ranged from 0.02 to 0.52 ppm, as shown by the following species: 0.36ppm (0.09-0.50) in Enteromorpha spp., 0.25 ppm (0.14-0.31) in Undaria sp., 0.19 ppm (0.02-0.52) in Porphyra spp., and 0.10ppm (0.02-0.24) in Laminaria spp. in that order. If these concentrations are converted to the wet bases, they will be about 1/4 to 1/5 of the present levels. In general, the samples collected from the east coast showed relatively lower levels than those from the south coast. The mercury concentrations found in the Korean seaweeds are lower than the permissible levels reported. 3. The concentration of cadmium in the air-dried seaweeds ranged from 0.02 to 1.48 ppm, and the levels in the different species showed in the following order: 0.97 ppm (0.41-1.18) in Hizikia sp., 0.33 ppm (0.03-0.63) Undaria sp., and 0.32 ppm (0.04-0.67) in Porphyra spp. The concentration of cadmium in the samples on the wet bases become 1/4 to 1/5 of the present level. The laver Porphyra spp. collected from the east coast showed relatively lower levels than those of the cultured species along the south coast. All of the concentrations are still below than the permissible levels. 4. In general, lead concentration is 0.20-1.31 ppm which is lower than the permissible level. The concentration becomes about 0.05-0.3 ppm on the wet base. 5. Copper concentration ranged from 0.90-17.0 ppn on the dry base which is about 0.2-4.0 ppm on the wet base. It is interesting to note that the samples collected from Busan region showed relatively higher levels than those sampled from other regions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.186-194
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• 2020

In this study, spectral analysis was conducted to identify environmental factors af ecting short-term changes in water temperature in the East, West and South coasts of Korea. The data used in the spectrum analysis is the 2016 summer water temperature, air temperature, tide level and wind data provided by Korea Hydrographic & Oceanographic Agency. In power spectrum results, peaks of water temperature and tide level were observed at same periods in West Sea (Incheon, Pyeungteak, Gunsan and Mokpo) and South Sea (Wando, Goheung, Yeosu, Tongyeong and Masan) where mean tidal range was more than 100 cm. On the other hand, periodicity of water temperature did not appear in East Sea and Busan where the mean tidal range was small. Coherence analysis showed that water temperature was highly correlated with tide in West Sea and three stations(Wando, Goheung and Tongyeong) of South Sea. Especially, correlation between water temperature and tide level in Wando and Tongyeong presented 0.96 at semi-diurnal period. Water temperature in Yeosu seems to have influenced by tide and inflow of fresh water. In Masan, water temperature is influenced by south wind, tide and inflow of fresh water. In East Sea, influence of tide on water temperature is small due to current and small tidal range. As a result of comparing the time series graph, stations where the correlation between water temperature and tide is high show that relatively cold water was inputted at flood tide and flow out at ebb tide. short-term variation of water temperature was affected by tide, but long-term variation over a month was affected by air temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.165-170
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• 1981

Recently an unknown microbial desease and some parasitic crustaceans are prevailing in the sea-weed farms of Uudaria pinnatifida along the south-eastern coast of Korea.(1) Green spots probably caused by the microbial pathogens were found on the fronds of Undaira Pinnatifide. Particularly they were densely distributed on the distal half of the fronds. The tissues of the green spot area rot off, and small holes with green colored margin are formed. The holes at the distal part of the fronds are enlarged and they finally coalesced each other. Then this process accelerates decaying of the distal ends of the fronds.. The fronds growing in the central part of the farms are usually severely damaged, whereas in the marginal area of the farm toward the open sea side the damage is less serious. An examination revealed that the deseased fronds bore a number of viable bacteria, $6.8\times10^5\;to\;1.2\times10^6$ per gram at $15^{\circ}C$, whereas the healthy fronds $1.1\times10^4$. Twenty-six kinds of colonies, 247 strains of bacteria, were isolated from deseased fronds, belonging to Moraxella, Achromobacter, Vibrio, Flavobacterium, Acinetobacter, Pseudomonas, etc. (2) Pinholes occurred in one series on the frond. They were probably caused by a harpacticoid copepod, Thalestris sp. Seven years ago when the disease was first found to occur the copepod was observed on the fronds from March of the year. Recently, however, they have been found as early as December of the previous year. (3) A gammarid amphipod, Ceinina iaponica, invades the pith of the midrib through holdfast of thalli. This rarely causes the longitudinal seperation of the entire frond through the midrib as they bore a tunnel in the pith. Sometimes holdfasts of tile heavy damaged thalli make the frond departed from the substrate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.75-83
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• 2020

This study investigated the effects of El Niño and La Niña on coastal upwelling in the East Sea of Korea using long-term (1967-2017) water temperature observation data and Oceanic Niño Index (ONI). As a result of time series analysis of water temperature, the occurrence frequency of summer coastal upwelling was the highest in the southeastern (Ulgi ~ Gimpo) coast. In 1987-1988 and 1997-1998, when the annual fluctuations of ONI plunged more than 2.5, the water temperature in whole coast areas of the East Sea (Busan ~ Goseung) rose by 4 ~ 7 ℃. The temperature structure of the East Sea coastal water was different when El Niño was strong with ONI above 1.5 and La Niña with strong ONI below -0.8. When El Niño is strong, the water temperature anomaly in coastal waters is negative. This is due to the strong baroclinic tilting and the formation of shallow temperature stratification in the coastal waters. The strong La Niña season is opposite to the strong El Niño season, whereas the water temperature anomaly is positive. In addition, the baroclinic tilting is weaker than the time of strong El Niño and the temperature stratification is formed deeper than the time of strong El Niño. The formation of temperature stratification at shallow depths when El Niño is strong can increase the probability of occurrence coastal upwelling caused by southerly winds in the summer season. On the contrary, when La Niña is strong, occurrence of coastal upwelling is less likely even if the southerly wind blows continuously. This is because the temperature stratification is formed at deeper than when El Niño is strong.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.554-559
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• 2011

To measure the proximate composition and mineral content of laver Porphyra yezoensis, we collected 30 raw and 30 dried laver from the major production area of the south coast of Korea (Busan, Goheung, Haenam, Wando). The approximate composition of a 100 g edible portion of raw laver was $89.9{\pm}1.4$ g moisture, $3.7{\pm}1.0$ g protein, $0.5{\pm}0.2$ g lipids, $2.1{\pm}1.8$ g carbohydrate and $3.9{\pm}0.6$ g ash. The approximate composition of a 100 g portion of dried laver was $8.9{\pm}1.6$ g moisture, $31.5{\pm}6.5$ g protein, $1.9{\pm}0.3$ g lipids, $48.4{\pm}6.5$ g carbohydrate and $9.3{\pm}1.1$ g ash. No clear regional variation in laver composition was observed. The mineral content of laver was expressed as dry weight. The mean macro mineral content per 100 g portion of raw laver was (in descending order): K ($1,979{\pm}863.0$ mg), Na ($1,063.2{\pm}498.8$ mg), P ($658.7{\pm}101.8$ mg), Mg ($432.3{\pm}83.5$ mg) and Ca ($394.2{\pm}136.5$ mg). In comparison, the mean micro mineral content of raw laver was (in descending order): Fe ($243.72{\pm}154.75\;{\mu}g/g$), Zn ($72.76{\pm}30.61\;{\mu}g/g$), Mn ($41.53{\pm}15.33\;{\mu}g/g$), Cu ($4.16{\pm}1.66\;{\mu}g/g$) and Ni ($0.43{\pm}0.70\;{\mu}g/g$) No clear regional variation in the mineral content of laver was observed; however, raw laver contained a higher mineral content than dried laver.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.219-224
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• 1976

The appearance of organochlorine pesticide residues in shellfish, seaweed, mud and water samples collected from south coast of Korean peninsula in September 1974 was surveyed to obtain the following results. 1) The residues in shellfish samples were found to be in the orders of Choongmoo > Yeosoo > Busan > Mokpo area, top-shell >short-necked clam > mussel > hard clam > red-shell, aldrin > ${\alpha}-BHC$ > heptachlor> ${\gamma}-BHC$ > dieldrin > heptachlor epoxide > endrin and in the range of $0-49\;{\mu}g/kg$ edible fresh muscle. 2) The residues in seaweed samples from Wando area were found to be in the orders of tangle > green laver > laver, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0-60\;{\mu}g/kg$ dry matter. 3) The residues in water samples were found to be in the orders of Yeongsan River > Nakdong River > Seomjin River > Choongmoo shellfish farm, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > heptachlor > dieldrin > heptachlor epoxide > endrin and in the range of $0-180\;{\mu}g/kl$ while those in mud samples were in the order of ${\alpha}-BHC$ > ${\gamma}-BHC$> aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0.7-18\;{\mu}g/kg$ dry matter. It should be noted that BHC contents of water samples from Yeongsan and Nakdong rivers were far above the recommended environmental levels in USA.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.5
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• pp.253-264
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• 2019

Storm surges caused by a typhoon occur during the summer season, when the sea-level is higher than the annual average due to steric effect. In this study, we analyzed the sea-level pressure and tidal data collected in 1 h intervals at Incheon, Kunsan, Mokpo, Seogwipo stations on the Yellow Sea coast to analyze the summer season storm surge and wave overtopping. According to our analyses, the summer mean sea-level rise on the west and south coasts is approximately 20 cm and 15 to 20 cm higher than the annual mean sea-level rise. Changes in sea-level rise are closely related to changes in seasonal sea-level pressure, within the range of 1.58 to 1.73 cm/hPa. These correlated mechanisms generates a phase difference of one month or more. The 18.6 year long period tidal constituents indicate that in 2090, the amplitude of the $M_2$ basin peaks on the southwest coast. Therefore, there is a need to analyze the target year for global warming and sea-level rise in 2090. Wave overtopping was simulated considering annual mean sea-level rise, summer sea level rise, the combined effect of nodal factor variation, and 100-year frequency storm surge. As a result, flooding by wave overtopping occurs in the area of Suyong Bay, Busan. In 2090, overtopping discharges are more than doubled than those in Marine City by the recent typhoon Chaba. Adequate coastal design is needed to prepare for flood vulnerability.