• Economic and Environmental Geology
• /
• v.33 no.6
• /
• pp.447-467
• /
• 2000

This study was carried out geochemically and mineralogically to define how Kunsan shore sediments are related to their terrestrial source rocks in the region of Keum River Basin, western Korea. As a whole the chemical composition for major elements, trace elements and rare earth elements analysis from shore sediments and river bed sediments doesn't show the big difference, and especially rare earth elements chondrite normalized patterns are almost same. Heavy minerals of shore sediments are identified as hornblende, epidote, ilmenite, garnet, hematite, magnetite, sphene and rutile. Compared with Taean Area of Seo et al. (1998) and Byeonsan Area of Kwon et al. (1999), Kunsan shore sediments of this study area were origined mostly from Keum River Basin.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.55 no.3
• /
• pp.252-263
• /
• 2019

In order to understand the tidal current and mean flow at the west channel of Yeoja Bay in the South Sea of Korea, numerical model experiments and vorticity analysis were carried out. The currents flow north at flood and south at ebb respectively and have the reversing form in the west channel. Topographical eddies are found in the surroundings of Dunbyong Island in the east of the channel. The flood currents flow from the waters near Naro Islands through the west channel and the coastal waters near Geumo Islands through the east channel. The ebb currents from the Yeoja Bay flow out along the west and the east channels separately. The south of Nang Island have weak flows because the island is located in the rear of main tidal stream. Currents are converged at ebb and diverged at flood in the northwest of Jeokgum Island. Tidal current ellipses show reversing form in the west channel but a kind of rotational form in the east channel. As the results of tide induced mean flows, cyclonic and anticyclonic topographical eddies at the northern tip but eddies with opposite spin at the southern tip are found in the west channel of Yeoja Bay. The topographical eddies around the islands and narrow channels are created from the vorticity formed at the land shore by the friction between tidal currents and the west channel.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1999.10a
• /
• pp.357-364
• /
• 1999

In recently site investigations, the need for the determination of dynamic soil properties such as dynamic modules of rigidity, elasticity, dynamic poison's ratio and damping ratio etc. is increasing for the astigmatic designs of the civil structures. To obtain some of the dynamic properties, measurement of elastic waves velocity, both P and S wave, is required. Among various methods to measure elastic wave velocity such and Down Hole, Cross Hole and Refraction etc., Suspension P.S. Logging has an advantage to use for the off-shore investigation where generation of the shock wave and traveling of the wave is difficult. In suspension P.S. logging, specially designed prove equipped with source of shock wave, two 3-channel receivers, departing 1m distance, and other auxiliary facilities is inserted down in a bore hole bottom and raised in predetermined interval, usually 1m or 2m, and measurement is conducted. P.S. logging have been conducted in a off-shore construction project near InChon in the west coast for the first in the country, and form the result, potential of the liquefaction of the subsoil was evaluated and compared with the conventional method.

• Economic and Environmental Geology
• /
• v.31 no.1
• /
• pp.69-84
• /
• 1998

A geochemical study was carried out to define how marine shore sediments are related to their terrestrial source rocks in the region of Taean and Byunsan Peninsula, western Korea. The lithology of the coastal part of the study area is composed of Pre-Cambrian granite gneiss, schist, Jurassic terrestrial sedimentary rocks, and Cretaceous plutonic intrusives. Shore sediments are transported from three drainage tributaries. The sediments consist of quatrz with clay minerals, such as illite, kaolinite, smectite, chlorite. Heavy minerals include hematite, ilmenite, rare amount of zircon and apatite. Compared to those in coastal rocks, amount of heavy minerals in the sediments is considerably low. The low content of heavy minerals is thought to be attributed to the heavy mineral detainment in the river beds and influences of tidal currents which cause heavy minerals to accumulate in specific spots. Chemical composition of the major and trace elements, trace elements, and REE chondrite normalized pattern suggest that shore sediments transported from the corresponding drainage tributary show close mineralogical and geochemical relationships with the source rocks distributed in the Taean and Byunsan Peninsula.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.31 no.2
• /
• pp.43-53
• /
• 1989

In this research programs, a series test was conducted to show the effects of freeze/thaw process on the various soil properties. The tests were carried out taken from the west sea shore of Korean peninsular and the west sea shore of Scotland, and their results are as follows; 1. There was a positive total heave in a freezing run, although water may he expelled for the sample initially. The water flow must he reverse' from expulsion to intake. 2. The confining pressure had an overriding influence on the heave and frost penetration, a sudden change of the axial strain at failure with strain rate was observed occuring at a strain rate between 10-5 and 10-6, and the initial friction angle of frozen clay was appeared zero. 3. There was shown a significant decrease in liquid limit of soil which was subjected to freeze/thaw process for the initial value of about 20% because of soil particles aggregation. 4. The cyclic freeze/thaw caused a sinificant reduction in shear strength and its thixotropic regain. The frozen/thawed soil exibited negative strength regain, particularly at high freeze/thaw cycles. 5. The freezing temperature greatly influenced on the failure strength of soils and this. Trend was more pronounced the lower the freezing temperature and shown the ductile failure with indistinct peaks.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.3
• /
• pp.1-11
• /
• 2011

The temporal variability of spring (March, April, May) monthly precipitation, precipitation effectiveness, monthly maximum precipitation, monthly precipitation of different durations, and the precipitation days over several threshold (i.e. 0, 10, 20, 30, 40, and 50 mm/day) of 59 weather stations between 1973 and 2009 were analyzed. Also to analyze the regional characteristics of temporal variability, 59 weather stations were classified by elevations, latitudes, longitudes, river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization. Results demonstrated that trends of variables increase in April and decrease in May except precipitation day. Overall trend of precipitation amount and precipitation effectiveness is same but precipitation effectiveness of several sites decrease despite the trend of precipitation amount increases which may be caused by the air temperature increase. Therefore more effective water supply strategy is essential for Spring season. Regional characteristics of Spring precipitation variability can be summarized that increase trend during May become stronger with the increase of latitude and elevation which is similar to that of Summer season. The temporal variability of variables showed different behaviors according to river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization.

• Journal of Marine Life Science
• /
• v.2 no.2
• /
• pp.56-61
• /
• 2017

This study examined the environmental characteristics of shore pollution sources in the southern part of the Sinan, Jangsando area in the West Coast of Korea. A shoreline survey of the watershed was conducted to identify the pollution sources and measure the water discharge rate and microbial hygiene of water and finally estimate the possible impact area of pollution. Forty five of pollution sources in total were identified and they were grouped into sewage (33), agriculture waste water (1) and waste water from inland fish farm (11). Nine among them were discharged into the seawater and discharge volume was 72,857~281,250 l/min. Fecal coliforms of St. 72 (sewage) and St. 74 (shrimp farm) were 490 MPN/100 ml and 49 MPN/100 ml and the impact zones of the pollution were 4,389 m and 1,900 m respectively.

• Journal of information and communication convergence engineering
• /
• v.2 no.1
• /
• pp.58-60
• /
• 2004

Sea level variations and sea surface circulations in the Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20∼30cm and 18∼24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15∼20cm and 10∼15cm, respectively. High variations in the West Sea were results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea were due to two branch currents (Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current (TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/see) in the Wonsan bay off shore with NKCC, and anticyclone (0.06 cm/see) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/see) in the northeastern area of Tushima island with TWC, respectively.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.879-881
• /
• 2003

Sea level variations and sea surface circulations in the Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20${\sim}$30cm and 18${\sim}$24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15${\sim}$20cm and 10${\sim}$15cm, respectively. High variations in the West Sea was results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea was due to two branch currents(Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current(TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/sec) in the Wonsan bay off shore with NKCC, and anticyclone (0.06 cm/sec) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/sec) in the northeastern area of Tushima island with TWC, respectively.

• Journal of the Korean GEO-environmental Society
• /
• v.16 no.4
• /
• pp.33-40
• /
• 2015

In the correlation formulas related to consolidation proposed at present, the analyzed areas are limited to certain overseas or domestic areas and in order to increase the number of data, experimental data of different areas are integrated and therefore in many cases application is difficult. In addition, models have been developed without clear statistic evaluation of the obtained data. Accordingly, this study divided the soft areas of the west coast into Hangang, Kumgang and Yeongsangang in order to maximally reduce uncertainty of the experimental data and performed normality test and regression analysis on the physical and dynamic characteristics. According to the analysis result, the compression index and the modified compression index had strong linearity and in all areas modified compression index and initial void ratio had closest correlation, followed by total unit weight, water contents and liquid limits. As for overconsolidation ratio with depth, the width of overconsolidation ratio was large when the depth was less than 5 to 6 m in all areas and when the depth was over 5 to 6 m, the ratio was constant.