• Economic and Environmental Geology
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• v.28 no.4
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• pp.395-404
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• 1995

The geologic structure of the Cheju volcanic island has been investigated by analyzing the gravity and magnetic data. Bouguer gravity map shows apparent circular low anomalies at the central volacanic edifice, and the maximum difference of the anomaly values on the island appears to be 30 mgal. The subsurface structure of the island is modeled by three-dimensional depth inversion of gravity data by assuming the model consists of a stacked grid of rectangular prisms of volcanic rocks bounded below by basement rocks. The gravity modeling reveals that the interface between upper volvanic rocks and underlying basement warps downward under Mt. Halla with the maximum depth of 5 km. Magnetic data involve aeromagnetic and surface magnetic survey data. Both magnetic anomaly maps show characteristic features which resemble the typical pattern of total magnetic anomalies caused by a magnetic body magnetized in the direction of the geomagnetic field in the middle latitude region, though details of two maps are somewhat different. The reduced-to-pole magnetic anomaly maps reveal that main magnetic sources in the island are rift zones and the Halla volcanic edifice. The apparent magnetic boundaries inferred by the method of Cordell and Grauch (1985) are relatively well matched with known geologic boundaries such as that of Pyosunri basalt and Sihungri basalt which form the latest erupted masses. Inversion of aeromagnetic data was conducted with two variables: depth and susceptibility. The inversion results show high susceptibility bodies in rift zones along the long axis of the island, and at the central volcano. Depths to the basement are 1.5~3 km under the major axis, 1~1.5 km under the lava plateau and culminates at about 5 km under Mt. Halla. The prominent anomalies showing N-S trending appear in the eastern part of both gravity and magnetic maps. It is speculated that this trend may be associated with an undefined fault developed across the rift zones.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.219-225
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• 2022

1950-meter-tall goddess is Seolmundae Grandmother with the head of the 1950m Hallasan Mountain Baengnokdam and the body of the mountain ridgeline. Seolmundae Grandmother in Jeju is a folk belief that has been passed down from generation to generation in Jeju. Unlike inland, Seolmundae Grandmother, which had femininity in the customs of Jeju, which was a matrilineal society, developed into an absolute faith in Jeju, metaphorizing that in some way it was inevitable. Seolmundae Grandmother was the only subject that could mentally solve the biggest problem for Jeju residents, even if they were disconnected from the mainland. In other words, Seolmundae Grandmother was unable to make underwear for Seolmundae Grandmother because it was short of 100 bottles of silk, the god of Hallasan, a huge being and a physical symbol. Therefore, Semyungju Grandmother gave up the bridge connecting the mainland and Jeju. In this paper, focusing on the fact that Mt. Halla, covered with snow in winter, is like a skein of silk thread that we usually use in our daily lives, the etymology of Seolmundae has been changed to Saengmyeongju, - Semyungju, which is a skein of fine silk. As a basis for this, there is a custom of tying a thread of silk in 'Semyungju', a shrine to Semyeongju in Halmangdang, 'Hanmosal' along the coast of Pyoseon-myeon. The silk thread is the core of the Packing DNA gene. The summit of Mt. Halla, Ninety-Nine Valleys, and five hundred generals, found in Seolmundae Grandmother or White Silk, expressed the symbols of Jeju. The Packing DNA gene was found to originate in the Jeongnang

• Geophysics and Geophysical Exploration
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• v.17 no.1
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• pp.28-33
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• 2014

We investigate the spatial distribution of highly conductive layer using the one-dimensional inversions of the new magnetotelluric (MT) measurements obtained at the mid-mountain (400 ~ 900 m in elevation) western area of Jeju Island and the previous MT data over Jeju Island, Korea. The conductive layer indicates the sedimentary layer comprised of Seoguipo Fomation and U Formation. There is a definite positive correlation between the top of conductive layer and the earth surface in elevation. On the contrary, the bottom of conductive layer has a negative correlation with the surface elevation. In other words, the conductive layer has a shape of convex lens, which is thickest in the central part. The basement beneath the conductive layer could be concave in the central part of Jeju Island. A kriging considering the correlation between the layer boundary and the surface elevation provides a reliable geoelectric structure model of Jeju Island. However, further studies, i.e. three-dimensional modeling and interpretation integrated with other geophysical or logging data, are required to reveal the possible presence of three-dimensional conductive body near the subsurface vent of Mt. Halla and the causes of the bias in the depths of layer estimated from MT and core log data.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.236-245
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• 2021

This study aimed to characterize the morphological variations in the vegetative and floral traits of 73 wild Lilium amabile plants from six habitats in Korea. It was observed that L. amabile is distributed nationwide at any altitude from 300 m (Mt Mangdaeam) to 1550 m (Mt Halla). The majority of the natural habitats of L. amabile were found on mountain slopes, and some were found in rugged mountain regions. The down-facing flowers of this species not only had many blotches but also dense trichomes, and the flowering time was found to be from mid-June to mid-July. ANOVA revealed significant variations in vegetative and floral traits among the six habitats, indicating that the environment has substantial influences on the various growth parameters of L. amabile, such as plant height; number of leaves, bracts, papillae, and flowers; leaf angle; and lengths of the anther, longest blotch, and nectary of the petiole. In addition, the vegetative and floral traits were found closely correlated with each other under the direct impact of the environment. These findings will facilitate to find the appropriate environmental conditions for the conservation and development of L. amabile population as future lily-breeding materials.

• Korean Journal of Plant Taxonomy
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• v.42 no.3
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• pp.211-214
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• 2012

Platanthera brevicalcarata Hayata (Orchidaceae), previously known to be distributed from Taiwan to southern Japan, was found in the Jeju-do, Korea. This species is distinguished from the related taxon Platanthera chlorantha by its small plant size, white sepal with distinct one green vein, and short-cylindrical spur. The local name Young-ju-je-bi-ran is originated from the local name of Mt. Halla. The morphological characters and illustration of the species are provided with line drawing and photograph from the natural habitat.

• Proceedings of the Speleological Society Conference
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• 1993.07a
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• pp.163-172
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• 1993

Cheju island is situated at about 90km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80$\times$40$km^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla (1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition ($SiO_2 = 53.07Wt% Fe_2 O_3=11.34Wt%, MgO=6.48Wt%, Na_2 O=3.07Wt%, K_2 O=1.05Wt%$), this rocks may belong to non alkalic basalt. K-Ar ages of two rocks samples from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

• Mycobiology
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• v.39 no.1
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• pp.1-6
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• 2011

Isolates of Ophiocordyceps heteropoda (Kobayasi) collected from Mt. Halla on Jeju-do, Korea were tested for mycelial growth on different agar media and in the presence of different carbon and nitrogen sources. Similarly, isolates were also incubated at different temperatures as well as under continuous light and dark conditions. Growth was better on Hamada agar, basal medium, and malt-yeast agar, but poor on Czapek-Dox agar. Different carbon sources such as dextrin, saccharose, starch, lactose, maltose, fructose, and dextrose resulted in better growth. Complex organic nitrogen sources such as yeast extract and peptone revealed the most effective growth. Mycelial growth was best at $25^{\circ}C$. The growth rate was faster in the dark than the light, but mycelial density was less compact in the dark.

• The Korean Journal of Ecology
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• v.14 no.3
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• pp.257-271
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• 1991

Two types in the species-importance, one type of carpinus laxiflora, carpinus tschonoskii, quercus serrata, quercus grosseserrata and pnus densiflora community and another type of abeies koreana community classified by zurich-montpellier method, were recognized based on the data from 81 sample plots. The forme species sequence-importance curves were coincidred with the ideal curve calculated by preston's lognormal-distribution theory(1948), with small variations among five communities, and the latter with that of motomura's niche pre-emption hypothesis(1932). It seems that plant community classified by phytosociological method based on the unit concept coincide with the vegetation type recognized by species population analyse based on the continuum concept and the dominance-diversity reflrcts on the difference in the coenocline among their plant communities.

• Mycobiology
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• v.40 no.4
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• pp.225-230
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• 2012

This study illustrates the status of thelotremoid Graphidaceae in South Korea. The taxonomy and systematics of thelotremoid lichens in the country have recently advanced greatly. Following the earlier known taxa from the group, four new records of the genus Thelotrema are reported and described briefly. An artificial key for all known species under thelotremoid group of Graphidaceae from South Korea is also provided.

• Proceedings of the Speleological Society Conference
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• 1994.11a
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• pp.108-109
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• 1994

Cheju island is situated at about 90km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80$\times$$40km^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla (1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition ($SiO_2=53.07Wt% Fe_2O_3=11.34Wt%, MgO=6.48Wt%, Na_2O=3.07Wt%, K_2O=1.05Wt%$), this rocks may belong to non alkalic basalt. K-Ar ages of two rocks samples from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.