• Ocean and Polar Research
• /
• v.28 no.2
• /
• pp.67-78
• /
• 2006

Six surface sediments from two offshore transects of Ulsan and Gampo, on the southeastern margin of Korea were taken for sediment and foraminiferal analyses. Sedimentary processes are dominated by reworking and resedimentation from storms in the area off Ulsan and hemipelagic suspension settling in the area off Gampo. Eighty-four foraminiferal species were identified in total assemblages, including 33species of living populations and 9 species of planktonic foraminifera. The characteristics of foraminifera showed differences of offshore environments between Ulsan and Gampo. The number of living species, species diversity and equitability in Gampo offshore area had higher values than those in Ulsan offshore area. However, planktonic/benthic(P/B) ratio showed higher in the Ulsan offshore area. The species diversity indices and P/B ratio indicated that environmental stability and surface-ocean productivity in the Gampo offshore area were relatively higher than the Ulsan offshore area. The difference of species compositions is useful for interpreting the paleoenvironments in mud deposits of the southeastern margin of Korea.

• Journal of Environmental Science International
• /
• v.23 no.2
• /
• pp.261-274
• /
• 2014

This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature ($0.5^{\circ}C$), low SST ($5^{\circ}C$) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70~100 ppb) in the non-clod water events, because of the low air temperature ($10{\sim}20^{\circ}C$) and high wind speed (3~5 m/s) around the southeastern coastal area.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.44 no.4
• /
• pp.304-311
• /
• 2008

Patagonian toothfish(Dissostichus eleginoides) was investigated in the southeastern Atlantic Ocean during the period of 19 March to 7 July 2007 by commercial bottom longliners. The number of 116 hauls were carried out individually in this study area by two bottom longliners during 111 days. The total catches were 89,559kg(9.91kg/100hooks) and 66,758kg(7.38kg/100hooks), respectively. Most Patagonian toothfishes were caught on the $46-48^{\circ}S$, $6-11^{\circ}E$ of southeastern Atlantic Ocean. Patagonian toothfish comprised 67.01-92.49%(by weight) of the catches in the southeastern Atlantic Ocean. No Antarctic toothfish (Dissostichus mawsoni) was caught during the surveys. Patagonian toothfish was found throughout the experimental area, but the density was considerably greater in the layer of 1,300-1,900m, where 49.88% of the fishes were caught. Smaller fishes were generally distributed to the shallow waters and larger fish were more frequently caught with the depth. Mean size of Patagonian toothfish increased with depth of capture. Accordingly economically profitable fishing activities for the Patagonian toothfish fishery requires an understanding of the size distribution of the Patagonian toothfish by depth.

• Journal of Ecology and Environment
• /
• v.38 no.4
• /
• pp.451-459
• /
• 2015

We investigated the pattern of floral diversity including naturalized plant species and three ecological factors (area, elevation and distance from mainland) of plant species on 53 uninhabited islands in Gyungsangnam-do, southeastern South Korea. A total of 206 taxa in 67 families were observed, and the species of Compositae was most common. Thirteen taxa in eight families of the naturalized plants were observed on 33 islands. The numbers of total plant species, area and elevation were significantly correlated, but no relationship with distance from the mainland was observed. In addition, no relationship was found among the numbers of naturalized plants, area and elevation. However, the average rate of naturalization on islands with different elevations differed significantly, indicating the smallest proportion of naturalized plant species was on high islands. Multiple regression of total species richness identified elevation as a significant factor, while no significant variables were correlated with naturalized plant species. Nonmetric multidimensional scaling (NMS) ordination identified three major variables, distance from mainland, number of naturalized plant species and elevation. These findings indicate that the geography of islands such as area and elevation affected the species richness of plants on uninhabited islands, while human disturbance had a greater effect than geography on the species richness of naturalized plants on islands in southeastern South Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.34 no.3
• /
• pp.287-293
• /
• 1998

Floating debris was recorded from a training ship, #1 Kwarnksan, of Pukyong National University with about 10 knots speed during March, May and July of 1997. The area sampled is the Southeastern Coast of Korea, divided into 40 unit segments on survey routes. Debris fabrication materials were categorized using the following ; man-made or natural wood items, paper, cardboard, nylon rope, netting, styrofoam and plastics, floating metal and glass containers. All identified items within a $100\;{\pm}\;2\;m$ wide band were recorded but ignored if beyond this boundary.The results of distribution and composition of floating debris in the area as follows:1. The quantities of debris during the duration of survey were distributed from 2~605 items per km2. The most obvious trend is the widespread distribution of all debris. 2. The highest densities of all debris were discovered in the coastal waters of Seoimal lighthouse, the southeastern part of Koje island, next near Nakdong estuaries. Especially styrofoam & plastics were observed in 77.4~87.2% of sampled area, next is wood items, 9.1~ 13.5%. And nylon netting & rope, 3.6%, was the third item of pollutant. Others are very small. 3. Compared with the East Coat of Korea, the quantities of all debus in theSoutheastern Sea are 6 times as large as the East Coast. The survey provides a basis for more detailed survey work in the South Sea. Further surveys are being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps on all sites of the Coast of Korea and contributed to the removal method, finding of sources, stationary area of debris.

• Journal of Radiation Protection and Research
• /
• v.5 no.1
• /
• pp.1-6
• /
• 1980

A portable count-ratemeter and a thermoluminescent detector ($CaSO_4:Dy$) have been used to obtain total gamma dose rates at approximately 50 locations during the course of several survey trips in the southeastern Korea. The purposes of these measurement were to provide a future reference data and to establish the approximate range of population exposure to the natural environmental radiation. The natural levels encountered ranged from a low of 14.6 microroentgen per hour to a high of 18.9 microroentgen per hour with a mean of $16.3{\pm}1.0$ microroentgen per hour. Among these results are the relatively high natural dose rate levels in the Masan area and Yangsan-Tongdosa area with the relatively low natural dose rate levels in the Gyeongsan-Cheongdo area and the Samrangjin-Jinyeong-Gimhae area.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.32 no.3
• /
• pp.266-272
• /
• 1996

The distribution and abundance of fish in the Cheju southeastern area was studied by the combined hydroacoustic and bottom trawl surveys in April 1994 and in July 1995, respectively. The main purpose of these investigations was to provide the basic data for this management and the biomass estimation of commercially important demersal fish stocks in this area. The hydroacoustic surveys were performed by using a 50 kHz scientific echo sounder system with a microcomputer-based echo integrator. Acoustical measurements of fish abundance and distribution were conducted along the cruise tracks of research vessel and during all trawl hauls by continuous echo sounding. The average weight-normalized target strength for demersal fish aggregations was derived from the relationship between the mean volume backscattering strength for the depth strata of trawl hauls and the weight per cubic meter of trawl catches. The geographical distribution of fish stocks in the 1994 survey area was investigated in relation to oceanographic conditions. The results obtained can be summarized as follows: 1. From the 1994 and 1995 survey data, the relationship between the mean volume backscattering strength (, dB) for the depth strata of trawl hauls and the weight (W, kg/$m^3$) per cubic meter of trawl catches was expressed by the following equation = - 32.8+ lOlog(W) The average weighted-target strength value at 50 kHz derived from this equation was .. 32.8 dB/kg. 2. In 1994 and 1995, both surveys showed a trend of decreasing fish abundance toward the southern area of the Cheju Island with high densities offish along the west coast ofth.e Tsushima Island. The highest demersal concentrations in the southern area of the CheJu Island appeared in bottom waters colder than $12^{\circ}C.$. . 3. From the results of combined bottom trawl and hydroacoustic surveys, the estunated fish densities in the southeastern area of the Cheju Island were 1.5488 x $10^-4$kg/$m^3$ in the 1994 surveyand 1.9498 x $10^-4$kg/$m^3$ in the 1995 survey, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.32 no.3
• /
• pp.257-265
• /
• 1996

The combined hydroacoustic and bottom trawl surveys were conducted in the Cheju southeastern area by the training ship "KAYA" belong to Pukyong National University in July 1995 and the traning ship "NAGASAKI MARl]" belong to Nagasaki University in April 1994, respectively. The main purpose of the investigations was to provide the basic data for the management and the biomass estimation of commercially important demersal fish stocks in this area. Fish samples were collected by bottom trawling from 10 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches were examined. The fish school target strength for demersal fish aggregations was related to the catchability of trawl net with a 90 mm mesh codend. The most abundant species in the 1995 trawl stations were Japanese flying squid, sword tip squid and red horsehead and that of the 1994 trawl stations Japanese flying squid and blackmouth goosefish. The average weight per cubic meter of trawl catches collected by bottom trawling in the Cheju southeastern area were $1.0791{\times}lO^-4$kg/$m^3$ in the 1994 survey area and $1.3636{\times}lO^-4$kg/$m^3$ in the 1995 survey area, respectively. The catch data by cover net suggest that the efficiency of trawl net could affect the weight normalized target strength values for demersal fish aggregations. That is, the average target strength per unit of weight dropped from - 33.1 dB/kg using the total catch by codend and cover net to - 30.5 dB/kg using only the catch data by codend, and a change of2.6 dB/kg was observed.ange of2.6 dB/kg was observed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.03a
• /
• pp.36-41
• /
• 2002

In this study we produced 1-dimensional p wave velocity structure of the crust using 449 P arrivals of 35 stations and we analysed hypocenters of the southeastern Korean peninsula area. A initial velocity model was selected from the priori studies and 30 different initial models were generated using random number generation from it. Using the veriest program 30 different velocity structures were calculated and the result show that velocities are 5.8 - 6.4 km/sec within 6 - 16 km depth and 7 $\pm$ 0.2 km/sec within 20 - 30 km with resonable resolution. Hypocenters were relocated by using resulted 1-dimensional velocity model as a initial model. Recalculated hypocenters'depth are shallower than initial data and epicenters show a little better lineality around study area but more much earthquake information are needed fur the determination of relation between epicenter distribution and geological tectonic structures.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.326-327
• /
• 2018

It is expected that the proportion of crushed aggregate will increase in order to fill the decreasing supply of sea sand in the southeast area. However, it is necessary to supply the least amount of sea sand to diversify the aggregate source, in order to minimize the mixing ratio of sea sand and crushed sand to minimize the structural stability of the concrete.