• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.403-420
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• 1997

Dodaecheon is a small river flowing into Asan Bay which is located in the middle part of the West Coast of the Korean Penninsula. We have investigated the change of depositional environment in Dodaecheon river basin during the middle Holocene. In the course of the research, the methods such as boring, radiocarbon dating, diatom and pollen analysis were employed. The Holocene deposits of the studied area are consisted of peat and gray silt layers, and contain many plooen and diatom fossils. Based on the results of diatom and pollen analysis, we conclude that the gray silt layers were sedimented owing to the transgression in the middle Holocene, and the peat layers by the regression or stabilzation of the sea level. The shoreline in the Post Glacial Age reached to the rivemouth of Dodaecheon at ca. 7,000 years before present(y. BP) and at that time the high tide sea-level(mean high water level of spring tide) rose to ca. 3m above present mean sea-level(m.a.s.l.). Since then to ca. 6,000y. BP, the high tide sea-level arrived to ca. 5m above present mean sea level further repeating minor transgressions and regressions. The peat layers of the coastal lowland of the West Coast were formed by the sea level fluctuations from 7,000 y. BP to 3,000 y. BP, and they were distributed 2 to 6 meters higher than the mean sea level of the present day. Most of them sedimented due to the high tide level are older and higher than those of the East Coast which were formed at the swale in the low tidal range environment.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.697-706
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• 2002

Authigenic siderite grains, ranging 100 to 250-${\mu}$m in diameter, are abundant in an about 8,600-year-old sediment layer in Namyang Bay, west coast of Korea. The siderites exhibit the aggregated spherulitic morphology with well-developed rhombs on the grain surfaces. They consist mostly of FeCO$_3$ (average, 65%) and MnCO$_3$ (average, 22%) with low Mg/Ca ratio (less than 0.4) in their bulk composition. A series of compositional ternary discrimination diagrams, together with high Mn and low Mg contents, show that only meteoric porewater was involved in siderite precipitation, assuming that depositional environment of host sediment is an organic-rich freshwater system. Considering a series of results such as radiocarbon age, authigenic Mn-rich siderite and lithological features, siderite-hosting sediment (unit Tl) is interpreted as freshwater swamp or bog deposition, infilling the topographic depressions that locally existed before the formation of mid-to-late Holocene tidal deposits. Center-to-margin compositional variation within individual grain is very systematic; Mn and Ca decrease towards the margin of a siderite grain, while Fe and Mg increase. It suggests that the spherulitic siderites were precipitated in this sedimentary layer in a series during the early diagenesis of MnOx-FeOx reduction under steady-state.

• 한국해양학회지
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• v.27 no.1
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• pp.78-90
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• 1992

The present study is aimed to investigate the relationship between the distribution of benthic macro fauna and environments in the Mangyung-dongjin tidal flat developed on the west coast of central korea. Samples were taken from 69 sites established on 8 transect lines running perpendicular to the coast. The 69 sites located in the range of -250 to 230 cm height from the mean sea level were categorized into 4 levels of exposure duration. The mean grain sizes of the surface sediments varied from 1.5 to $7.9{\varphi}$. Silty sands and sands were dominant sediment facies on the tidal flat. A total of 64 species of invertebrates was collected and the mean density was $1,335{\;}indiv{\cdot}\textrm{m}^2$. The dominant species was Laternula cf. limicola of Bivalvia (71% of total counts), followed by Umbonium thomasi of Gastropoda (22%), and Lingula anatina of Brachiopoda (2.6%). These 3 species comprised 95.5% of total individual number. The distribution of benthic animals was closely related with the duration of tidal exposure. Perinereis association was the characteristic for the most exposed area, and followed by Macrophthalmus and Bullacta-Mactra-Umbonium association along the degree of exposure duration.

• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.151-162
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• 1999

This study is a comparative analysis of sea level and 500hPa surfaces between dry year and wet year, which are selected by variability of precipitation and standardized anomalies in Korea in early autumn. While the amount of precipitation of early autumn decreases, the variability of precipitation increases rapidly reflecting the strength and weakness of Kaul Changma front and the occurrences of the typhoonic precipitation. The regional distribution of the variability of precipitation shows west-high, east-low pattern in which the east coast and the southeastern coast shows low, but high in the southwestern coast. In the anomalies distribution of sea-level and 500hPa surfaces, during dry year, the northern part of Siberia and the core area of North Pacific high shows negative anomalies, on the contrary, there were positive anomalies in wet year at the same areas. In addition, at the 500hPa level, while the Korean peninsula was located at the west of deep trough with low zonal index in dry year, the peninsula was influenced by weak trough with high zonal index showing strong zonal flow in wet year. During dry year the height of 500hPa surface is low at the north of $40^{\circ}N$, but high in wet year. In consequences, this study identified that the occurrences of dry year and wet year were influenced by the seasonal variations of the strength and the weakness of North Pacific high and Siberian high.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.179-183
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• 2001

Shortnecked clam, Ruditapes philippinarum, is one of the very important shellfish produced in south-western coast of Korea. But it's ready to be polluted and have sand in flesh because it mainly inhabit in silt at the inside of coastal area. This study was carried out to obtain informations about the elimination of sand in shortnecked clam harvested from western coast of Korea. During rearing shortnecked clams in water tank, the elimination rates of sand from them at 6, 13, 23, $28^{\circ}C$ were 59.0, 88.2, 97.9, $96.1^{\circ}C$ after 48 hours, respectively. The sand was eliminated above $95^{\circ}C$ from the shellfish at 32,9 to $40\%_{\circ}$ of salinity after 48 hours. But the sand elimination from them was incomplete and inconsistent at 10 to 20 of salinity. The sand was eliminated rapidly at pH 1.9 to 9.0 however, its elimination was not effective at neutral or acidity range, It was found that the sand elimination was most effective at $23^{\circ}C, 35\%_{\circ}$ salinty and pH 9.0. Reasonable flow rate for sand eliminate in shortnecked clam was above 150 L/min./shellfish $m^3$ under both 3,000 and 4,000 L/shellfish $m^3$, and above 100 L/min,/shellfish $m^3$ under both 6,000 and 8,000 L/shellfish $m^3$ in water tank.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.184-189
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• 2001

Surf clam, Mactra veneriformis, is a important shellfish produced in south-western coast of Korea. But it's ready to be contaminated and have sand in flesh because it mainly inhabit in silt at tHe inside of coastal area. We determined optimum conditions for the sand elimination and microbial depuration in the shellfish harvested from western coast of Korea. It was found that the most effective conditions of process water for the sand elimination were $23^{\circ}C$, $32.9-35.0\%_{\circ}$ salinity and pH $7.9\~9.0.\;A$ surf clam contained about 210 mg of sand whose $94\%$ was eliminated after 24 hours in natural sea water ($32.9\%_{\circ}$ , pH 7.9) controlled at $23^{\circ}C$. To eliminate both sand and microorganisms contaminated in surf clam, the process water should be run during at least 36 hours for the former and 24 hours for the latter at 150 L/minute/$m^3$of shellfish, when its volume was above 4,000 L/$m^3$ of shellfish in 2 tons of tank.

• Acta Via Serica
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• v.3 no.2
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• pp.49-72
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• 2018

The extensive maritime trade network between the Harappan and Mesopotamian civilizations as early as the $3^{rd}$ millennium BCE is a testimony to the long maritime trade history of India. From the dawn of the historical epoch, the maritime trade network of India expanded extensively. The findings of a large number of coins, pottery, amphorae and other materials from Italy and various other European countries, west Asia, China, Korea, Africa, the Arabian Peninsula, Sri Lanka, Southeast Asia and Far-East countries in India, particularly in the coastal regions, are a testimony to the dynamic maritime trade of India with other countries in the early period. Similarly, pottery, sculptures, inscriptions and other materials of Indian origin are also found in those countries. The depiction of different types of ships on the coins, paintings, sculptures, seals and sealing, exhibit the variety of vessels used for navigation and other purposes in the early period. The over 7500 km-long coastline of India is well known for its seaports located at river mouths or outlets to the sea. The Periplus Maris Erythraei, Ptolemy, and Indian literary sources mention many seaports on the western coast of India. Interestingly, archaeological investigations in many of these port towns have yielded material evidence exhibiting their dominant role in transoceanic trade and commerce with many countries in the early period. This paper discusses in detail all the major ancient seaports on the western coast of India and their maritime trade activities. At the outset, the paper briefly deals with the Harappan's maritime network, their seaports and the type of ships of that period. Following this, the maritime trade network of India during the historical period with various countries in the east and west, the traces of Indian influence and materials abroad and foreign materials found in India, the products exported from India, the trade winds and navigational devices and the depiction of ships on the coins, paintings, and sculptures of the period are discussed in detail. After briefly highlighting the coastline of India and its favourable nature for safe anchorage of ships and the strategic position of the seaports of western India, an extensive account of the major ancient seaports of western India like Barygaza, Ashtacampra, Gundigar, Kammoni, Khambhat, Bardaxema, Suparaka, Calliena, Semylla, Sanjan, Naura, Tyndis, Muziris, Nelcynda and other seaports, and their maritime trade activities are given based on archaeological excavations and explorations, literature, epigraphy, foreign accounts, and numismatic evidence.

• Conservation and Restoration of Cultural Heritage
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• v.1 no.1
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• pp.29-37
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• 2012

The West Stone Pagoda at Gameunsaji Temple Site constructed in the 7th century is mainly composed of dark grey dacitic tuff bearing small numerous dioritic xenoliths. These xenoliths resulted in small holes due to differential weathering process from the host rocks. Physical strength of the pagoda was decreased due to weathering and damage caused by petrological, biological and coastal environmental factors. The southeastern part of the pagoda was extremely deteriorated that the rock surface showed exfoliation, fracture, open cavity, granular decomposition of minerals and salt crystallization by seawater spray from the eastern coast. The stone blocks were intersected by numerous cracks and contaminated by subsequent material such as cement mortar and iron plates. Also, the pagoda was colonized by algae, fungi, lichen and bryophytes on the roof rock surface and the gaps between the blocks. As a result of ultrasonic test, the rock materials fell under Highly Weathered Grade (HW) or Completely Weathered Grade (CW). Thus, conservational intervention is essentially required to prevent further weakening of the rock materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.20-25
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• 2009

Thirty-eight Vibrio spp. were isolated from the sea waters harvested from the 22 stations located on the west coast of the Korean peninsula in September 2006. The isolates consisted of V. parahaemolyticus (n=21), V. alginolyticus (n= 16) and V. cholerae non-01 (n=1), among which 35 isolates displayed resistance against two of the tested antibiotics. Among the 38 isolates, 18 isolates exhibited multi-drug resistance against more than four 4 antibiotics. In particular, minimum inhibitory concentration $(MIC)_{50}$ and $MIC_{90}$ of ampicillin-resistant isolates were as high as $2,048{\mu}g{\cdot}mL^{-1}$ and $4,096{\mu}g{\cdot}mL^{-1}$ respectively. $\beta$-lactamase production was examined to analyze the ampicillin-resistance. Some Vibrio spp. isolates produced $\beta$-lactamase, however antibiotics resistance pattern and $\beta$-lactamase production were not clearly related to each other. A genetic relationship between resistance and gene expression was confirmed in the ampicillin-resistant isolates.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.45-59
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• 2016

Vegetation and soil conditions of four sites in west coastal forests in South Korea, were examined to analyze the relationship between Pinus thunbergii forests structure and soil conditions. The P. thunbergii forests were divided into four clusters; 1) P. thunbergii - Prunus sargentii var. sargentii, 2) P. thunbergii - Robinia pseudoacacia, 3) P. thunbergii - P. densiflora and 4) P. thunbergii - Quercus serrata. The soil of each site was poor in chemical characteristics but good enough for land plants to grow because of its low salt concentration. According to the results by CCA Ordination, certain excessive soil nutrition has influenced on vegetation and specific species distribution. Forty eight species were found in the whole sites of coastal forests and some species appeared in every site. They are P. thunbergii, R. pseudoacacia, Rhus chinensis, Idesia polycarpa and Morus alba. For the tree species importance value, P. thunbergii was followed by R. pseudoacacia, Q. serrata, P. densiflora, Celtis sinensis, M. alba, I. polycarpa and Q. mongolica in order.