• The Journal of the Petrological Society of Korea
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• v.26 no.1
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• pp.93-98
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• 2017

In this paper, we propose a lava flow simulation program to predict the range of lava flows area and thickness of lava flows during volcanic eruptions. The map information is represented as a 'cell' with observed values per fixed area such as DEM and a lava flow prediction algorithm using a cellular automata model is performed to predict the flow of lava flows. To obtain quantitative data of lava flows, fluid properties of lava flows are defined as Bingham plastic fluid and derived equation is applied to the rules of cellular automata. To verify the program, we use a 30m resolution DEM provided by USGS. We compared simulation results with real lava flows for the Pu'u'O'o crater area in Hawaii, which has erupted since May 24, 2016.

• The Journal of the Petrological Society of Korea
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• v.5 no.1
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• pp.66-83
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• 1996

We report petrography, mineral chemistry, and major and trace element chemistry for rare tholeiites in Cheju island where alkalic rocks predominate. Available age data indicate that the tholeiitic magmatism was younger than 0.49Ma, possibly younger than 0.17 Ma. The tholeiites are generally fine-grained, porphyritic rock and show intergranular texture with lath-shaped plagioclase ($An_{61-46}$), orthopyroxene (bronzite) and olivine ($Fo_{78-67}$). Characteristically, two kinds of clinopyroxene (pigeonite and augite) occur only in groundmass. The tholeiites have normative quartz and show limited compositional variations ($SiO_2$=51.0-52.5 wt%; Mg＃=54-60). Major and transitional metal element variations of tholeiites are distinct from those of alkaline rocks in MgO diagram, suggestingthat the two rock types cannot be simply related to differentiation process from the same magma. The ratios among $K_2O$, Rb, Ba, Nb and La are similar for both tholeiites and alkali basalts, however the ratios between the elements (P, Y and Yb) having an affinity with garnet and the above elements are higher for tholeiites than for alkali basalts. These trace element ratios suggest that the tholeiites and alkali basalts were produced by different degrees of partial melting from a similar sources material (garnet lherzolite mantle).

• Horticultural Science & Technology
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• v.31 no.4
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• pp.512-516
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• 2013

Pear cultivar 'Sinhwa' (Pyrus pyrifolia var. culta Nakai) was originated from a cross between 'Niitaka' and Whasan' with the aims of improving the fruit quality and the traits of cultivation and of early maturing more than 'Whasan' cultivar at Pear Research Station of National Institute of Horticultural & Herbal Science, Rural Development Administration in 1995. 'Sinhwa' was preliminarily selected in 2004 and named in 2009. The tree shows vigorous growth habit and semi-spread characters like 'Niitaka'. Furthermore, it has a sufficient and well upkeep of the flower bud, so it can be more easily cultivated in orchards. In the flower characteristics, flowering time of 'Sinhwa' is $11^{th}$ April like as maternal parent 'Niitaka'. Also 'Sinhwa' has short of pollen grains, so it is need above two pollinizer cultivars. 'Sinhwa' is highly resistant to black leaf spot (Alternaria kikuchiana) and relatively strong to pear scab (Venturia nashicola) in field condition. The optimum harvest time is around Sep. $15^{th}$ in Naju, which is ahead of 'Whasan' about 10 days in the harvest period. The fruit shape is oblate and fruit skin color is yellowish-brown during harvesting time. The average weight of fruit is 627 g, and the soluble solids content is $13.0^{\circ}Brix$. The flesh is very soft and juicy, and renders good eating quality. Shelf life is about 30 days under the room temperature condition.

• The Korean Journal of Quaternary Research
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• v.15 no.1
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• pp.37-45
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• 2001

Morphometric parameters such as cone height, cone height/width ratio($H_{co}$/$W_{co}$), cone height/difference between cone width and crater width ratio($H_{co}$/$W_{co-cr}$) and slope angle are measured to investigate the rates of slope development of scoria cones in Cheju Island. The parameters systematically decrease with increasing age of scoria cones, suggesting that comparative morphology of scoria cones is a useful age indicator. Cone age is most highly correlated with $H_{co}$/($W_{co-cr}$ or average slope angle because summit craters are infilled and eventually removed by erosional processes. The average slope angle is estimated as $\theta_{ave}$= $tan^{-1}$/〔2.$H_{co}$/$W_{co-cr}$〕. Cheju Island was formed through four eruptive stages during Pleistocene. The youngest cones of stage 4(0.1~0.025Ma) have a mean average slope angle of 23.6$\pm$1.7$^{\circ}$, whereas stage 3(0.3~0.1Ma) and stage 2(0.6~0.3Ma) cones have mean values of 18.9$\pm$$1.7^{\circ}C$and 12.6$\pm$$1.9^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.475-486
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• 2009

The geological survey of the Mokdo island is for the fist time conduted in Korea history. The island had erupted before $70{\sim}80$ million years as a strato-volcano. The original volcano had been dissected for long periods up to the skeletal stage through the planeze stage. If the island area is surveyed afterwrds in detail, the position of crater is available to be found, either. The coastal terrace is found at 50m level in Mokdo island which is correlated to its fourth plane. The microgeomorphological features as coastal terrace, cliff, sea cave, wave-cut bench, sea stacks, notch, and tafoni, etc. were described. The Mogdo island is located off Molundae at the extension of Nagdong Jeongmaeg(낙동정맥 洛東正脈) showing a "floating turtle". The name of Mogdo island is needed to change to the "Yoo-goo-do" which means the swimming turtle. The Mokdo island is as suitable tourist attraction for if has enough touism sesouccesein sea. The deuelopsment of coartal sightseeing anound lighthoure and uninhabited islands will hare an impontant effect upon construction of the oceanic capitol city of Busan Haabor. The master plan built up an arboretum on the island, a coastal oceanarium, a seaweeds garden under sea coast, and other oceanic culture-spaces is completed in the study.

• Journal of the Speleological Society of Korea
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• no.67
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• pp.81-89
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• 2005

It tries to introduce it enough here searching for a lot of documents because it is a region to which we cannot go because there is not a lot of material though it searches the Internet searching for a lot of material to investisate the current state of the cave in the Changbaek Mountain and the Gillim region and it saw. The snow is covered on the white head top of a mountain by one during names 'the told white head mountain', and the Changbaek Mountain puts a white snow on the head if it sees from a long distance and is metaphor in elderly person's gray hair, various documents. Because the white snow between longtime periods is coveted, it is said that it was called the Changbaek Mountain. And, it tries to introduce material concerning the Chansbaek Mountain and the Gillim region here and to explain material concerning the cave.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.23-23
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• 2010

스발바드 서측에 위치하는 스피츠버겐 하부의 암석권맨틀의 분화시기를 규명하기 위하여, 두 개의 독립적인 방사성동위원소 시스템인 Lu-Hf과 Re-Os 시스템을 스피넬 페리도타이트(spinel peridotite)에 활용하였다. 전암에 대한 Re-Os 계통(Re-Os 에러크론, 알루미노크론, Re-결핍연대 등)은 연구지역의 페리도타이트가 대류하는 맨틀로부터 고기원생대/후기시생대에 분리되었음을 지시한다. 흥미롭게도 이런 연대는 페리도타이트내 단사휘석 결정들에 대하여 얻어진 Lu-Hf 에러크론 연대와 일치한다. 또한 시료 내에 지구화학적으로 기록된 현무암질 액의 결핍정도 역시 계통적으로 위의 연대를 지지한다. 위 연대는 스피츠버겐 서측부에 보고된 가장 오래된 지각의 연대와 일치한다. 따라서 연구지역의 암석권맨틀이 연약권으로부터 분리된 것은 접촉하고 있는 지각과 동시기적으로 이루어진 사건임을 알 수 있다. 연구지역은 팔레오세 이래로 복잡한 지구조적 응력장 변화(압축에서 신장환경으로의 변화)를 겪었다. 그럼에도 불구하고 지각과 커플링된 암석권맨틀이 현존한다는 것은 연구지역내 응력장변화가 대규모의 암석권 디라미네이션(delamination)을 유발하지는 않았다는 것을 의미한다. 그러므로 북극권의 화산활동을 설명하기 위하여 북극권 상부맨틀에 존재한다고 알려진 듀팔(DUPAL) 같은 부화된 물질의 성인으로 일부의 연구자들이 주장하여 온 디라미네이션된 암석권맨틀의 존재는 설득력이 없다고 판단된다.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.681-692
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• 2013

We aimed to evaluate the effectiveness of the Giggenbach bottle method and develop the related pretreatment and analytical methods using artificial fumarolic gases. The artificial fumarolic gases were generated by mixing $CO_2$, CO, $H_2S$, $SO_2$, $H_2$, and $CH_4$ gas streams with a $N_2$ stream sparged through an acidic medium containing HCl and HF, with their compositions varied by adjusting the gas flow rates. The resultant fumarolic gases were collected into an evacuated bottle partially filled with a NaOH absorption solution. While non-condensible gases such as CO, $H_2S$, and $CH_4$ accumulated in the headspace of the bottle, acidic components including $CO_2$, $SO_2$, HCl, and HF that were dissolved into the alkaline solution. Like other acidic components, $H_2S$ also dissolved into the solution, but it reacted with dissolved $Cd^{2+}$ to precipitate as CdS when $Cd(CH_3COO)_2$ was added. The non-condensible gases were analyzed on a gas chromatography. Then, CdS precipitates were separated from the alkaline solution by filtration, and they were pretreated with $H_2O_2$ to oxidize CdS-bound sulfide into sulfate. In addition, a portion of the solution was also pretreated with $H_2O_2$ to oxidize sulfite to sulfate. Following the pretreatment, the resultant samples were analyzed for $SO_4^{2-}$, $Cl^-$ and $F^-$ on an ion chromatography. In the meanwhile, dissolved $CO_2$ was analyzed on a total organic carbon-inorganic carbon analyzer without such pretreatment. According to our experimental results, the measured concentrations of the fumarolic gases were shown to be proportional to the gas flow rates, indicating that the Giggenbach bottle method is adequate for monitoring volcanic gas. The pretreatment and analytical methods employed in this study may also enhance the accuracy and reproducibility of the Giggenbach bottle method.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.201-219
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• 2017

The Jinan Basin which includes Maisan locates in the central part of the northern boundary of the Yeongnam Massif. The basement rocks of the Jinan Basin and surrounding area are Precambrian gneiss and Mesozoic granite which were exposed on the surface before Cretaceous. The Jinan Basin, one of the Cretaceous pull-apart basins in South Korea, formed along the Yongdong-Gwangju fault system. Maisan is composed of conglomerate deposited in the eastern slope of the Jinan Basin showing the shape of horse ears and the unusual topography where many tafonies were developed. The strike slip fault that caused the Jinan Basin was connected to the deep depth so that the magma formed at 200 km depth could have extruded on the surface causing active volcanic activity in and around the Jinan basin. As a result, Cheonbansan composed of pyroclastic rocks, Gubongsan consisting of volcanic neck and WoonilamBanilam formed by the lava flow, appear around Maisan forming a specific terrain. After the formation of the Jinan Basin and surrounding volcanic rocks, they uplifted to form mountains including Masian; the uplifting time may be ca. 69-38 Ma. At this time, the Noryeong mountain range may be formed in the regions which extended from Chugaryeong through Muju and Jinan to Hampyeong dividing the Geumgang and Seomjingang water systems. Due to the ecological barrier, the Noryeong mountain range, Coreoleuciscus splendidus living in the Geumgang water systems was differentiated from that in the Soemjingang water system. In addition, the Geumgang and Mangyeong-Dongjingang water systems were separated by the Unjangsan, which developed in the NNW direction. As a result, diverse ecosystem have been established in and around Maisan and at the same time, diverse cultural and historical resources related to Maisan's unique petrological features, were also established. Therefore, Maisan and surrounding area can be regarded as a place where a geotourism can be successfully established by combining the ecological, cultural and historical resources with a geological heritage. Therefore Maisan and surrounding areas have a high possibility to be a National Geopark and UNESCO Global Geopark.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.67-80
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• 2000

We studied petrological and geochemical characteristics of the Mesozoic volcanic rocks in the Da Hinggan Ling area northeast China, and discussed tectonic settings and origin of the Mesozoic volcanic rocks in northeast Asia. Volcanic rocks in Da Hinggan Ling area are composed of alkaline to subalkaline basalt-basaltic andesite-andesite-dacite-rhyolite, showing typical BAR(basalt-andesite-rhyolite) association. However, most of the volcanic rocks are basaltic and rhyolitic in composition, and andesitic rocks are relatively rare, which shows bimodal characteristics. Rb, Ba, Th and other incompatible element contents in the volcanic rocks are enriched, but the contents decrease with increasing the compatibility. REEs are fractionated and REE patterns of volcanic rocks are characterized by a high LILE/HFSE. On the tectonomagmatic discriminant diagram of Hf-Th-Nb, they fall into the fields for subduction-related destructive plate margin basalts and its differentiates. We suggest that the tectonomagmatic setting of Da Hinggan Ling area was located at the continental margin arc related with subduction environment during the Mesozoic time or may be derived from mantle plume contaminated geochemically from subducting slabs, although it is, at present within the Asia continent.