• Journal of the speleological society of Korea
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• v.41 no.1
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• pp.3-15
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• 1994

Geographically Cheju Island is located in the southmost part of Korea. Cheju Province, the largest. island in Korea, consists of one major island, Cheju, and other minor islands including Chuja Island. The province is located in around 140 km from Mokpo on the north, about 272 km from Pusan. Tsushima Island of Japan on the northeast, and Shanhai of the China across the East China Sea to the west.(omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.759-770
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• 1997

The general flow patterns in the Cheju Strait have been investicated by analyzing the current observations measured in $1986\~1989$ by current meter mooring in 3 north-south sections in the Cheju Strait and at 4 observation points around Cheju Harbour, and measured in $1981\~1987$ by drogue tracking. 1. In the Cheju Strait, there are eastward or northeastward residual currents, which implies that sea waters flow into through the whole western section and flow out through the whole eastern section in the Cheju Strait. The velocity of residual currents are $5.2\~30\;cm/sec$ in 10 m layer and $1.3\~24cm/sec$ in mid-bottom layer. Generally, the flow is strong along the deepest through and the northern part, and weak in the shallow areas near Chuja Islands and Bogil Island. 2. In the western entrance of the Cheju Strait, the observed mean residual velocity is 6.93 cm/sec and the volume transport is 0.384 Sv. There are a big discrepancy between the observed residual currents and the geostrophic currents. 3. Near the frontal areas northwest to Chuja Islands, warm and saline offshore waters, flow northward about 5 miles into the southern coastal areas of the Korean Peninsula in flood, and flow back rather eastward or southeastward than southward in ebb. So, warm and saline waters flow along coastal areas, being mixed with coastal waters. As a result, the northwestern area of Chuja Islands plays a role of the entrance of influx of warm and saline offshore water to the southwestern coastal areas of the Korean Peninsula. It should be stressed that this flow pattern is not due to the residual flows, but to the temporal (tidal) flows.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.862-875
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• 1996

The CTD data observed in the sea northwest of Cheju Island have been analyzed to figure out the seasonal circulation around Cheju Island. Warm and saline waters flow into the Yellow Sea through the middle region of the Yellow Sea in winter and along the west coast of Korean Peninsula in summer. On the other hand, cold and less saline waters flow out of the Yellow Sea through the middle region in summer and along the west coast of Korean Peninsula in winter. These flows make the seasonal circulation around Cheju Island. As dynamics, the monsoon wind and the variation of Kuroshio transport have been suggested. Comparing the observational result, the circulation driven by the variation of Kuroshio transport is strengthened by monsoon winds in the numerical model.

• The Journal of Engineering Geology
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• v.2 no.1
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• pp.70-91
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• 1992

Cheju and Oahu island are similar in geology, characterized by same types of volcanic activities during the late Tertiary to the early Quaternary. The occurrence of groundwater in both islands depend on two basic elements, permeability of volcanic rocks and precipitation. However, groundwater occurrence in Oahu is much more controlled by dike complex in the regional volcanic rocks. There are two different types of groundwater in both islands. One is perched groundwater standing at any high altitude, and the other is basal groundwater developed near the coastal area. The groundwater quality of Cheju island is good in general for drinking. But many wells near the eastern coastal area are salt intruded due to over pumping activities and the area of salt water intrusion has increased landward from the year of 1970. This feature of salt water contamination is similar at Pearl Harbour in Oahu island. In order to prevent this salt water contamination into fresh groundwater reservoir on Cheju island, it is urgently asked to make groundwater flow study along the coastal area on terms of groundwater potentials and their maximum ultimate exploration.

• The Korean Journal of Malacology
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• v.13 no.1
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• pp.71-90
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• 1997

A soudy on the distrobution and seasonal changes of the benthic macrovertebrates community was performed on the 5 intertidal rocky shores of Chujado in the Cheju-Channel during four seasons from March 1996 to February 1997.The macroinvertebrates identified in Chujado totally composed of 9 phyla, 18 classes, 38 orers, 147 species. The macroinvertebrates idetified according to the stations were 9 phyla, 138 species in Sinyangri(ST. 1); 8 phyla, 134 species in Younghungri(ST. 4);and 8 phyla, 131 species in Daeseori(ST. 5); The species diversities of the lower intertidal zones were higher than those of middle and upper intertidal zones, however, the seasonal appearance in number of species was not different among the stations. The vertically distributed dominant species in intertidal zone were; Nodifittorina exigua and Nerita japponica in the supralittoral zones; Monodonta labio labil and Buccinulum ferrea in the upper zones; Septifer keenae and Lunella coronata corensis in the middle zones; Purpura clavigara, S. keenae and Pomatoleios krausii in the submiddle zones; and Actinia mesembryanthemum, Tetracliata squamosa japonica and N. schrenckii in the lower zones. The intertidal community structures between Chujado and Cheju coast showed that Chujado composed of fewer number of species and lower value of species diversity and richness indices than Cheju coast.

• Korean journal of applied entomology
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• v.17 no.3 s.36
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• pp.161-166
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• 1978

Is. Dae Heucksan-do and Is. Heucksan-do and Is. Hong-do are located in the southwestern, apart 110km from Mockpo city, Korea., and the spider fauna of this area has never been explored. The author collected the spiders from these Islands in August 1974. Findings were; 1) 83 species of spiders belonging to 17 families, including 5 undetermined species. 2) Leptoneta sp., Carrhotus sp. (A), Marpissa sp. and Synagelides sp. are reserved for future study. 3) The materials were not sufficient for general discussion and conclusions of the spider fauna of these Islands. However, results can be summarized as follows: 7 northern species $8.9\%$ 9 southern species $11.5\%$, 4 cosmopolitan $5.1\%$ 4) The common species of mainland China were 41 $51.9\%$. 5) As the result of this survey, the spider fauna of this area is similar to that of the Is. Cheju-do and Is. Tsushima, in the south eastern area, and have much more common to China than any another area in Korea.

• Korean Journal of Ichthyology
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• v.17 no.2
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• pp.148-151
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• 2005

The Japanese blacktail triplefin, Springerichthys bapturus, is redescribed based on three specimens (36.6~55.4 mm SL) from Soheuksan and Jeju Islands. This is the first reliable record of the species from Korea. The specimens are characterized by having 26~28 second dorsal spines, 22~26 anal soft rays, 27~30 anterior lateral line scales, and intensive coloration of head and tail.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.35-44
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• 2003

Considering possible legal and policy problems with regard to the Cheju Strait, a central issue is whether the Cheju Strait should be treated as Korean territorial sea or an international strait The claim that the strait is territorial sea has been based on the use of a straight baseline method of dermarcation With the use of straight baseline, Korea claims that the breadth of the Cheju Strait is only 20.7 miles at its narrowest point and therefore the strait becomes the territorial sea of Korea. The consideration cf marine pollution has weighed heavily in claiming the Cheju Strait as territorial sea. Pollution resulting from the accidents cf tankers caused by fire, collision, or stranding in the Cheju Strait and the Korea Strait would be enormous, affecting the entire coastal waters of the south coasts cf Korea's mainland and Japan's Tsushima Islands areas. Catastrophic pollution in the Cheju Strait could also come from the accidents cf large-size oil tankers passing through the Korea Strait from the Malacca Strait Although the Korean government considers the geographic and socioeconomic conditions sufficient to justify Korea's claim of the Cheju Strait as territorial sea, it believes that declaring it so would raise considerable legal conflicts with maritime states. In view of the legal difficulties and the need to meet the problems arising from the growing vessel traffic in the Cheju Strait, the sea lanes and traffic separation schemes may be considered an alternative to the internationalization of the Cheju Strait Even if the Korean government dose not do so, the regime of innocent passage should be applied to vessels passing through the Strait and should not suspend innocent passage through the Strait. Therefore, the Korean government needs to have a more legal, pragmatic, functional and managerial approach than a purely sovereign and selfish approach to the solution of legal matters of the Cheju strait For this purpose, the UN Convention on the Law of the Sea would serve as a guide and also self-restraint and cooperative approaches would become norms governing the resolution of the law of the sea issues in the Cheju Strait.

• Journal of the korean society of oceanography
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• v.32 no.1
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• pp.1-7
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• 1997

Surface current fields in the eastern East China Sea (ECS) were constructed by analyzing trajectories of 58 satellite-tracked surface drifters released during 1991-1996. Composite trajectories and 20-minute-by-20-minute box-averaged current vectors show that the basic current pattern composes of: the Kuroshio main stream, which turns eastward toward the Tokara Strait; a northward branch current of the Kuroshio on the ECS outer shelf deeper than 100 m; and an anticyclonic circulation in the northern Okinawa Trough west of Kyushu. The northward branch current sharply changes its direction to the northeast when it crosses a line connecting Cheju Island, Korea and Goto Islands, Japan. The basic pattern of current field changes slightly from winter to summer, and the main axis of the Tsushima Current in the Korea Strait is found to shift seasonally. The drifter experiment does not support the claim that the Yellow Sea Warm Current is separated from the northward branch current on the outer shelf southeast of Cheju Island. We suggest that the use of the term 'Tsushima Current' be limited to the northeast channel flow in the Korea Strait. The new term 'Kuroshio Branch Current' is suggested for the northward branch current on the outer shelf south of Cheju-do, which is separated from the Kuroshio.

• 한국해양학회지
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• v.24 no.3
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• pp.132-147
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• 1989

A total of 83 surface sediments and 55 sea water samples, collected from the southwestern sea of Cheju Island, were analyzed in order to understand their textural characteristics, geochemical composition and the clay mineralogical features. The sediments were subdivided into ten textural classes, namely clayey sand, slightly gravelly muddy sand, sandy clay, clay and mud. The coarse and fine-grained mixed sediments are distributed in the northern part and around the Island, whereas the fine-grained deposits are mainly distributed in the central and southern parts of the study area; small scale mud patches are distributed in the southwestern and northern parts of Cheju Island. The high concentration of total suspended matter in study area gradually increase toward the southwestern and northwestern offshore area. The concentration of geochemical elements is as follow: the content of Mn, Al, Zn, Cr, Cu and Sn increase toward the southern part which is covered mainly with fine-grained deoposits, whereas the content of Ca, Mg and Ag is higher in the northern area; the elements such as Ni, Na, Fe and Pb are more concentrated relatively in muddy deposits rather than in sandy sediments. The light minerals such as Na-Ca feldspars show a high content around the Socotra Rock, toward the Soheugsan and Cheju Islands, but the K-feldspars are relatively high around the Cheju Island. It was noticed that the provenance of these sediments is partly influenced by the geological characteristics near the island. X-ray diffractogram for clay minerals from the southeastern mud patch and around the Soheugsan Island shows the diagnostic calcite peak indicating that the greater part of these clay fraction may have been derived from present and ancient Hwangho River. The high concentration of smectite in the northern part near the Cheju and around the Soheugsan Islands, eastern side of Socotra Rock probably result from supplies smectite altered from volcanic materials distributed in the Cheju Island and Socotra Rock, whereas the samples near the Chuja and northern parts of the Cheju Island contain weak calcite peak and high concentration of kaolinite and chlorite which is closely related to the geolgical characteristics on the adjacenting land area.