• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.571-578
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• 2014

The boundaries of ROK maritime jurisdictional area remains unclear as two Koreas failed to draw clear maritime boundaries at the armistice agreement and there are no clear maritime boundaries with China and Japan. After the Korean War, the United Nations Command established the northern limit line(NLL) as well as the area of operations(AO) to enforce the DPRK's compliance with the armistice agreement and has been controlling all of the maritime and air activities in the region. ROK also has been controlling the passage of DPRK vessels in the area. Within the AO, third nation vessels have freedom of navigation, Yet, due to the division followed by the Korean War, ROK classifies DPRK as a hostile state and unique controling system is applied to DPRK vessels. Since the establishment of the AO, many changes have been occurring such as adoption of the UN Convention on the Law of the Sea(UNCLOS) and two Koreas' joining the UN. Also, there are continuous inter-Korean conflicts. Therefore, the geographical span of the AO needs to be reconsidered. Furthermore, a legal measure which ensures ROKN vessel's functional capability of controling DPRK vessels must be introduced. This thesis examines post-Korean War DPRK vessel control system in the Korean peninsula as well as how it should be improved.

• Journal of the Korean Geographical Society
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• v.37 no.4
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• pp.357-370
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• 2002

Present work aims to investigate the species composition, physiognomy and distribution of arctic-alpine and alpine plants(AAP) of the Korean Peninsula. The dominance of AAP in the northern Korea may be due to the frequent exchanges of floras with circumpolar regions for the seek of the glacial refugia during the alternate Pleistocene glacial epochs. The post-glacial climatic amelioration pushed AAP back northwards and upwards, so they now shows disjunctive distribution on separate mountain tops. The diverse morphological adaptations of AAP to severe environmental conditions, viz. the dominance of perennial species, stunted tree growth, multiple protection of leaves, krummholz, and dwarf shrubs, are the result of long-term graduall development which have safeguarded the survival of AAP in a such a harsh cryo-climatic area. The appearance of the Korean endemic AAP reflects the long-term isolation of species in Korea, and the local environmental diversities which have both accentuated this isolation and aided the development of genetic diversity. Evergreen broad-leaved AAP at c. 1,500m to 1,800m and above are now endangered because of the competition from down-slope plants, and from the global warming.

• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.159-178
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• 2012

Since the suggestions on the paleo-glacial landforms in and around the northern high mountains of Korean Peninsula by some western and Japanese scientists in the early 1900s, the likelihood of the glacier existence in the Baekdusan over the Quaternary glacial period has been had in common among most of the Korean geomorphologists. In the other meaning, some have cast doubt on the likelihood the paleo-glacier in the Baekdusan because there has been no unequivocal evidences for the glacier such as striation, moraines, except morphologic characteristic landforms possibly related to glacier. Here we show some evidences for the existence of the glacier in the Baekdusan and their cosmogenic $^{36}Cl$ exposure ages over the late Quaternary and would put forward a model on the Quaternary landscape evolution of the Baekdusan, with a focus on the relationship of 1000 AD explosive eruption and the glacial landforms. The exposure ages constrained by cosmogenic $^{36}Cl$ abundances of the col surface of the western slope located below the glacier yield 46~26 ka, which is inphase with the last glacial period. Given all the evidences above, we can draw a conclusion that the glacier existed on the Baekdusan over the late Quaternary and the style of glaciation changed from extensive ice cap through valley glacier to restricted cirque.

• Korean Journal of Plant Taxonomy
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• v.45 no.1
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• pp.72-95
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• 2015

In order to illustrate the flora of vascular plants distributed in the area of Mt. Hambaek-san and its neighboring mountains, the authors collected vascular plants intensively on Mt. Hambaek-san (1,573 m), Mt. Geumdae-bong (1,418 m) and Mt. Daedeok-san (1,307 m) from April of 2012 to August of 2014. All of them consisted of 90 families, 310 genera, 532 species, 4 subspecies, 73 varieties and 13 forms, with a total of 622 taxa. The total number of vascular plants in the investigated area was 808 taxa (17.55% of all vascular plants in Korea) with the addition of voucher specimens from previous investigations. Among the collected plants, endemic ones were 21 taxa, rare and endangered ones 26 taxa, naturalized ones 30 taxa, useful ones 464 taxa, and floristically specific ones of Korean floristic zones 62 taxa except for species of the first and second grade. Among the floristic zones of the Korean Peninsula, this investigated area showed the typical vegetation of a temperate middle province into which more northern elements than southern elements flowed.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.615-630
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• 2022

This study was conducted to investigate the flora of Mt. Seongdeok (Ganghwa-gun) in Korea. From the results of nine field surveys from March 2020 to July 2022, a total of 445 total taxa, representing 397 species, nine subspecies, 35 varieties, two forms and two hybrids were identified, which were placed in 273 genera and 93 families. The plant formation of Mt. Seongdeok is a deciduous broad-leaved and conifer mixed forest, which is common in the middle part of the Korean Peninsula. Most of the mountain is covered by a young secondary forest, which is mainly composed of Quercus ssp. and Pinus ssp. Among them, five taxa were endemic to Korea, one taxon were endangered plant and two taxa were red list plants. The floristic target plants amounted to 27 taxa, specifically one taxon of grade V, four taxa of grade III, seven taxa of grade II, and 15 taxa of grade I. And 43 taxa were northern lineage plants. A total of 46 species of alien plants were identified, with a Naturalized Index of 10.3%, an Urbanization Index of 11.7%, and six plants that disturbed the ecosystem. Our results provide basic data on vascular plants flora, and plant diversity and distributional changes.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.75-75
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• 2001

We report Sr, Nd and Pb isotope data of clinopyroxene separates from ultramafic xenoliths and their host basaltic rocks in Jeju Island, Baekryeong Island, Boeun and Ganseong, Korea. The isotopic data of the xenoliths and host basalts are distinctly different from those of Korean basement rocks. Except for two xenoliths from Ganseong, all samples in this study have isotopic ratios within the combined range of MORB-OIB data. All basaltic rocks have Nd-Sr-Pb isotope compositions different from those of xenoliths, indicating that the host basaltic magma did not derive from the lithospheric mantle where the xenoliths originated. The range of isotopic composition of xenoliths is much greater than that observed in host basalts, which reflects small-scale heterogeneity of the lithospheric mantle. The greater isotopic heterogeneity of the lithospheric mantle probably reflects its long-term stability. The spinel peridotite xenolith data of Jeju Island, Baekryeong Island and Boeun display mixing hyperbolas between DMM and EM II end members. Since Jeju basalts have EM II-like isotopic signature, the mixing relationship shown by the isotopic data of the Jeju xenoliths can be interpreted as the result of infiltration of metasomatic fluid or melt derived from basaltic magma into DMM-like lithospheric mantle. In contrast to other xenolith sites, the Ganseong xenoliths are dominantly clinopyroxene megacryst and pyroxenite. Clinopyroxene megacrysts have different isotopic ratios from their host basalt, reflecting its exotic origin. Two Ganseong xenoliths (wherlite and clinopyroxenite) have much enriched Sr and Nd isotopic ratios and Nd model ages of 2.5-2.9 Ga, and plot in an array away from the MORB-OIB field. The mantle xenoliths from Korean Peninsula have similar $\^$87/Sr/$\^$86/Sr,$\^$143/Nd/$\^$144/Nd and $\^$207/Pb/$\^$204/Pb ratios to, but higher $\^$208/Pb/$\^$204/Pb ratios than, those from eastern China, indicating that Korean xenoliths are derived from the lithospheric mantle with higher Th/U ratio compared with Chinese ones. The isotopic data of xenolith-bearing basalts of Baekryeong Island and Ganseong, along with Ulreung and Dok Islands, show a mixing trend betlveen DMM and EM I in Sr-Nd-Pb isotopic correlation diagrams, which is also observed in tile northeastern Chinese basalts. However, the Jeju volcanic rocks show an EM II signature that is observed in southeastern Chinese basalts. The isotopic variations in volcanic rocks from the northern and southern portions of the East Asia reflect a large-scale isotopic heterogeneity in their source mantle.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.47-56
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• 2011

The research was conducted to find optimal habitats of warm-temperate evergreen broad-leaved trees, and to investigate climate factors to determine their distribution using classification tree (CT) analysis. The warm-temperate evergreen broad-leaved trees model (EG-model) constructed by CT analysis showed that Mean minimum temperature of the coldest month (TMC) is a major climate factor in determining distribution of warm-temperate evergreen broad-leaved trees. The areas above the $-5.95^{\circ}C$ of TMC revealed the optimal habitats of the trees. The coldest month mean temperature (CMT) equitable to $-5.95^{\circ}C$ of TMC is $-1.7^{\circ}C$, which is lower than $-1^{\circ}C$ of CMT of warm-temperate evergreen broad-leaved trees. Suitable habitats were defined for warm-temperate evergreen broad-leaved trees in Korea. These habitats were classified into two areas according to the value of TMC. One area with more than$-5.95^{\circ}C$ of TMC was favorable to trees if the summer precipitation (PRS) is above 826.5mm; the other one with less than $-5.95^{\circ}C$ of TMC was favorable if PRS is above 1219mm. These favorable conditions of habitats were similar to those of warm-temperate evergreen broad-leaved trees in Japan. We figured out from these results that distribution of warm-temperate evergreen broad-leaved trees were expanded to inland areas of southern parts of Korean peninsula, and ares with the higher latitude. Finally, the northern limits of warm-temperate evergreen broad-leaved trees might be adjusted accordingly.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.151-162
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• 1980

To clarify the dispersion of pollutants introduced in the coastal region, a series of current measurements, the drogue and drift bottle experiments as well as the dye diffusion experiments were carried out in Onsan Bay and in the coastal waters of Ubong-ri near Ulsan. In the southeastern coastal region of Korean peninsula, that is, in the outside of Onsan Bay, the flood tidal current flows south-south-westward, and the ebb current flows north-north-eastward at a maximum speed of 1.0-1.1 knots at spring tide. In an inlet south of Cape Ubong, an anticyclonic eddy of 1 km in diameter is usually formed during both flood and ebb flows. The tidal current predominates in Onsan Bay at around spring tide. The maximum speed around spring tide was observed to be approximately 0.14 knot, while it was slower than 0.1 knot and variable at neap tide when the wind drift current played an important role. The flood tidal current flows westward while the ebb flow flows eastward in the northern region of the bay. The flood tidal current in the southern region of the bay flows west-north-westward, while the ebb current east-north-eastward. Wind drift currents in the coastal region of southern Korea are generally deduced to be southward in winter, the monthly mean speed being approximately 0.1 knot. Dye solution released at the northwestern corner in Onsan Bay was transported by eastward ebb tidal current toward the mouth of the bay dispersing by the wind. The apparent diffusion coefficient at 150 minutes after release in the bay was calculated to be $4.4\times10^4\;cm^2.sec^{-1}$, whereas that in the anticyclonic eddy was more or less smaller.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.259-281
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• 2013

This research aims to analyze Baekdu mountain are with it's the east flowing streams which are the issues on the old maps. Also, it will analyze the eastern flows, Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. Also, it will analyze the north-eastern flows, Heukryong river; Songhwa river; Sockpyung river; Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. The mainly issued Baekdu mountain's north-eastern flows can be classified into six different flows by the classifications, it proves that there are various Baekdu mountain north-eastern flows on the old maps. the two streams theory of Tomoon and Doman river explains the perspective of the northern expansion, and the one stream theory expresses it by stating Boongye and Sockpyung river as the same one. However, in the case of the meaning of Boongye river is Haeran river on the middle of one stream theory map, there is no region expanding perspective but the same border perspective that Korean peninsula and China match. Boongye river is expressed into four different meanings. (1) It is the same river with Sockpyung and shows the regional expanding perception. (2) It is the same river with Tomoon and the down stream of Tomoon river.(3) It expresses the current name, Haeran river. (4) It simply means the river shows the boundary.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.602-612
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• 2011

Jeju Island, a volcanic island located in South Korea, has been one of the main targets of geophysical and/or geological studies because of its tectonic importance related to the volcanism and tectonic link to the southern part of the Korean Peninsula. Recently, as a number of broad-band magnetotelluric (MT) measurements were made, we have examined the deep part of the island. In such an insular setting, it is not easy to properly recover the deep structures such as the lower crust and the upper crust using MT data, because their low-frequency components are strongly affected by the surrounding sea of the island. In this study, we apply the sea-effect correction to the existing MT data collected at a total of 102 sites in Jeju Island. The sea-effect correction makes remarkable changes in the observed MT data at frequencies below 1 Hz, clearly indicating the existence of a conductive lower crust. The 2-D inversion results for both Jeju Southern Line (JSL) and Jeju Northern Line (JNL) show that the transition zone separating the resistive upper crust and conductive lower crust exists at a depth of 20 km on average.