• Title/Summary/Keyword: geological differences

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Modeling the Impacts of Increased Urbanization on Local Meteorology in the Greater Seoul Area (수도권지역 도시화가 국지기상에 미치는 영향 모델링)

  • Kang, Yoon-Hee;Kim, Yoo-Keun;Oh, In-Bo;Hwang, Mi-Kyoung;Song, Sang-Keun
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1361-1374
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    • 2010
  • The impact of urbanization on local meteorology (e.g., surface temperature, PBL height, wind speed, etc.) in the Greater Seoul Area (GSA) was quantitatively evaluated based on a numerical modeling approach during a 1-month period of 2001 (9 Sep. through 8 Oct. 2001). The analysis was carried out by two sets of simulation scenarios: (1) with the global land use and topographic data from the U.S. Geological Survey (USGS) in 1990s (i.e., LU-USGS case) and (2) with the land use data from the Environmental Geographic Information System (EGIS) along with the 3 sec elevation data from the Shuttle Radar Topography Mission (SRTM) in 2000s (i.e., LU-EGIS case). The extension of urban areas in the GSA (especially, the southern parts of Seoul) accounted for 1.8% in the LU-USGS case and 6.2% in the LU-EGIS case. For the simulations, the surface temperature and PBL height due to urbanization in the LU-EGIS case was higher (the differences of up to $0.1^{\circ}C$ and 36 m, respectively) than those in the LU-USGS case, whereas the wind speed (up to 0.3 $ms^{-1}$) in the former was lower than that in the latter at 1500 LST. The increase in surface temperature due to urbanization in the GSA (especially, the southern parts of Seoul) was led to the strong convergence of air masses, causing the early sea breeze and its rapid propagation to inland locations. In addition, the vertical mixing motion in the extended urban areas for the LU-EGIS case was predicted to be stronger than that for the LU-USGS case and vice versa for the original urban areas.

Geological Characteristics of Kyongju-Ulsan Area : Palaeomagnetism and Magnetic Susceptibility of the Granitic Rocks in the Ulsan Fault Area (경주-울산일원에 대한 지역지질 특성연구 : 울산단층주변 화강암류의 잔류자기와 대자율)

  • Kim, In-Soo;Son, Moon;Jung, Hyun-Jung;Lee, Joon-Dong;Kim, Jeong-Jin;Paik, In Sung
    • Economic and Environmental Geology
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    • v.31 no.1
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    • pp.31-43
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    • 1998
  • A total of 469 granitic samples were collected from 44 sites in the Ulsan fault area, southeast Korea. According to the previous petrographic studies, the granitic rocks have been divided into four groups (Hornblende biotite granodiorite, Hornblende granite, Biotite granite and Alkali-feldspar granite). NRM intensities, values of low field magnetic susceptibility, and magnetic behaviors during stepwise demagnetization experiments suggest rather a three-fold classification: In this scheme, Hornblende granite and Biotite granite are grouped together, as they did not show any significant differences in magnetic characteristics. Based on the Ishihara (1979)'s criterion, Alkali-feldspar granite is classified as ilmenite-series granite, whereas others are classified as magnetite-series granite. In the eastern part of the study area including the Tertiary basin area, declinations of site-mean characteristic remanent magnetizations (ChRMs) show clockwise deflection of more than 30 from the reference direction of east Asia. Both along and in the adjacent region of the Ulsan fault-line, however, no deflection of remanent direction was observed. A boundary line between the deflected and undeflected site-mean ChRMs is defined in this study, which runs roughly parallel to the Ulsan fault-line at the distance of about 6km eastward from the fault-line. We suggest that this newly found boundary line, which we call Yonil tectonic line, released dextral simple shear stress acted in the southeastern part of the Korean peninsula during the opening stage of the East Sea in the Early Cenozoic.

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A Study of Coarse Bed Materials in Small Streams in Rocky Mountains (로키 산맥 소하천의 조립질 하상 퇴적물에 관한 연구)

  • Kim, Jong-Wook
    • Journal of the Korean Geographical Society
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    • v.33 no.1
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    • pp.1-16
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    • 1998
  • This study surveyed intensively the relationships between grain size of coarse bed materials and some principal factors in channel system, drainage area and channel slope, in Rocky Mountains. The result of this research shows that there are statistically significant relationships between these factors. Generally, the grain size and the channel slope exponentially decreased in the study area with the increase in drainage area. However, there are great differences in grain size and channel slope between upstream and downstream channels. The boundary lines are commonly located at near the mouth of canyon. From these results, it can be concluded that the bed material characteristics and the channel slope are strongly influenced by the geological and geomorphological background of the drainage basin in this study area.

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Soil organic carbon characteristics relating to geomorphology near Vestre Lovénbreen moraine in Svalbard

  • Jung, Ji Young;Lee, Kyoo;Lim, Hyoun Soo;Kim, Hyun-Cheol;Lee, Eun Ju;Lee, Yoo Kyung
    • Journal of Ecology and Environment
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    • v.37 no.2
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    • pp.69-79
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    • 2014
  • Soil organic carbon (SOC) in the Arctic is vulnerable to climate change. However, research on SOC stored in the high Arctic regions is currently very limited. Thus, this study was aimed at understanding the distribution and characteristics of SOC with respect to geomorphology and vegetation in Svalbard. In August 2011, soil samples were collected near the Vestre Lov$\acute{e}$nbreen moraine. Sampling sites were chosen according to altitude (High, Mid, and Low) and differences in levels of vegetation establishment. Vegetation coverage, aboveground biomass, and SOC contents were measured, and density-size fractionation of SOC was conducted. The SOC content was the highest in the Mid site ($126.9mg\;g^{-1}$) and the lowest in the High site ($32.1mg\;g^{-1}$), although aboveground biomass and vegetation coverage were not different between these two sites. The low SOC content measured at the High site could be related to a slower soil development following glacial retreat. On the other hand, the Low site contained a high amount of SOC despite having low vegetative cover and a high ratio of sand particles. These incompatible relationships between SOC and vegetation in the Low site might be associated with past site disturbances such as runoff from snow/glacier melting. This study showed that geomorphological features combined with glacier retreat or melting snow/glacier effects could have affected the SOC distribution and vegetation establishment in the high Arctic.

A Technical and Economic Evaluation of Cobalt-rich Manganese Crusts (심해저 망간각 개발의 경제성 평가)

  • Park, Se-Hun;Yang, Hee-Cheol
    • Ocean and Polar Research
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    • v.31 no.2
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    • pp.167-176
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    • 2009
  • Cobalt-rich manganese crusts on seamounts have received an increasing amount of attention as future resources for Co, Ni, Cu, and Mn. A dearth of detailed information regarding the relevant distribution characteristics, mining technologies, and ore processing technologies, however, has precluded potential evaluations of the technical and economic advantages of these crusts. In the past 4 years, Korea has undertaken a survey of the cobalt-rich manganese crusts in and around the Magellan Seamount and Mid-Pacific Mountains. This paper introduces the preliminary feasibility study of the distribution features and R&D results centered around the development of the cobalt-rich manganese crusts. The evaluation model was developed by modifying the model for the manganese nodules. In addition to considering the geological and geophysical differences between the manganese nodules and the cobalt-rich manganese crusts, an ore dressing subsystem was installed in the model. The mining subsystem is composed of a self-propelled collector--a pipeline with submersible hydraulic pumps for crust lifting. The smelting and chlorine leach method was selected for metallurgical processing. The production scales were established at 2,500t/y of cobalt metal. The production of three metals--cobalt, nickel, and copper--was considered in terms of metallurgical processing. The economic feasibility analyses demonstrated that the payback period was 11.4 years, the NPV was 36M$, and the IRR was 9.6% with the economic factors in the case of a cobalt price of US$ 25/lb. It was also demonstrated in this study that the payback period was 8.6 years, the NPV was 154M$, and the IRR was 14.0% in the case of a cobalt price of US$ 30/lb. This indicates that the approach under consideration appears to offer greater potential given the predicted metal prices.

Analysis on the sea effect in the Korean Peninsula using 2-D MagnetoTelluric(MT) modeling (2차원 MT 모델링을 이용한 한반도에서의 해양효과 분석)

  • Yang, Jun-Mo;Kwon, Byung-Doo;Lee, Chun-Ki
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.259-264
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    • 2006
  • In MT and GDS survey for probing the deep structure of the Earth, surrounding seas play a critical role to distort the response of in-land geological structure. This study analyzed the sea effect in the Korean Peninsula and investigated the spatial and frequency dependency of it using 2-D MT modeling. Due to conductance difference between the Yellow Sea and the East Sea, the effect of each sea shows the dependence on frequency and spatial distance from each coastline. In general, TM mode responses are more severely affected by surrounding sea than TE mode one and the differences between 1-D model and TM mode responses are in inverse proportion to the frequency. Assuming that the lowest limit of acquired frequency is 0.001Hz for the given 1-D structure, the separation distance, where the sea effect can be negligible, is approximately 100km for the East Sea and 40-50km for the Yellow Sea, respectively. But, this separation distance is a function of the 1-D electrical structure of subsurface and the used frequency.

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Types and Characteristics of Skirts of Minority Races in Yunnan Province (운남 지역 소수민족 치마의 조형적 특성)

  • Kim Hye-Young;Cho Woo-Hyun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.7 no.3
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    • pp.167-179
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    • 2005
  • Skirts hold an important position in dress culture among various dress forms, being worn by more than half of mu. In this study, Chima is defined as garment for lower part of the body without crotch sewing, contrasting with trousers. The authors classify and compare the formation of the skirts of minority races in Yunnan area, based on Korean Chima, understanding the forms of skirts and examining the composition, color, pattern and material. For the study, the authors investigated 57 pieces of skirts among 341 pieces of minority races dresses from Yunn Nationality Museum collection exhibited at Korea Folk Village in May 2003, and referred to customs materials and photos in various literatures. Skirts in Yunnan area are divided into 6 areas, that is, seamless one-piece skirt area, wrapskirt area and mixed type skirt area. Skirt formation factors from the effect of environment such as climate, lifestyle and means of production were studied, and characteristics, differences and similarities were reviewed. Figure of skirts are studied by compostion, color, material, and technique. By composition, they can be classified based on the similarity to Hanbok (traditional Korean dress). By color, worshipped color and preferred color vary by races and by area. Materials vary in kinds and thickness by area with various climate. By technique, national characteristic patterns are inherited through national traditional dyeing and embroidery. It is not easy to conclude based on single item of skirt, but we suggest that national dresses have been settled through the mutual supplements between the effect of social and cultural exchange such as historical inheritance, geological environment, religion and production activity and the various forms of skirts from changes in shape, color, material and wearing form of dresses.

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A Study of Effects on Building for Cracks by Ground Vibration -Pusan Andesite- (지반진동이 건물의 균열에 미치는 영향에 관한 연구 -부산 안산암지역을 대상으로-)

  • 안명석;박종남;이영대
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1173-1179
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    • 1999
  • A study was made on crack developments of the nearly building due to rock blasting for road construction at the 623 Common Block near the rear side of the Gamchun Habor. The gelogy of the study area is composed of andesite, which belongs to the Kyungsang System of the Cretaceous Period. For 3 months of blasting events, the vibration velocity data were measured at the site just in front of the K freezing factory. The data were divided into 4 groups according to the period of blasting(i.e, DATA 1, DATA 2, DATA 3 and DATA 4), for deriving K and n values. As a result, DATA 1 shows that K and n were 83.3756 and -0.848, respectively, and then K and n were progressively increased in absolute values for the follow-up groups and the last DATA 4 shows K and n were 2980.4898 and -1.502, respectively. Such differences in K and n values may be due to partly : 1) variations geological characteristics, from the upper rather weathered, fisssuring soft rocks at the earlier stage less weathered and fissuring hard rocks at the later stage of blasting events, and 2) the geometry between the blasting and detecting points.Among the total count of 225 blasting events, the number exceeding the safety limits of 0.5cm/sec was 20(8.9% of the total), the maximum displacement detected at the crack gage was 0.25mm, the level of which is far less to cause the occurrence and development of any cracks to the K factory. Therefore, it was confirmed that there were no damages such as structural failure or safety problem to the building.

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Benthic Foraminiferal Communities of Surface Sediments in the Southwestern Continental Shelf of the East Sea, Korea (동해 남서대륙붕 표층퇴적물의 살아있는 저서성 유공충 분포)

  • Woo, Han-Jun;Oh, Jae-Kyung;Kim, Hyo-Young;Choi, Dong-Lim;Lee, Chi-Won
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.2 no.1
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    • pp.14-20
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    • 1997
  • The southwestern continental shelf of the East Sea, Korea developed mud deposits as a belt in the inner shelf area from Pusan to Pohang. The general surface sediments consist of very poorly to poorly sorted muddy sediment. The differences of physical, geological and geomorphic conditions in the study area may control and produce distinctive foraminiferal populations. To establish a baseline of environment for the muddy sediments in the southwestern continental shelf of the East Sea, 17 stations were sampled and proved to contain 45 species of living benthic foraminifera. Analysis of the foraminiferal populations in cluster analysis recognized to five habitat zones. These habitat zones contain distinctive cooccurrences of the entire occurring species. Foraminiferal community composition appeared to be closely interrelated of water masses, depths, nutrients and sediment characters.

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Thermal and Mineralogical Characterization of Ca-montmorillonite from Gampo area : Comparison between Jugjeon and Yongdongri deposit (감포지역(甘浦地域) Ca-몬모릴로나이트의 광물학적(鑛物學的) 및 열적특성(熱的特性) : 죽전(竹田) 및 용동리지역(龍洞里地域) 광상(鑛床) 비교연구(比較硏究))

  • Moon, Hi-Soo;Ahn, Jae Yeong;Choi, Sun Kyung;Kim, Moon Young;Morgan, D.J.
    • Economic and Environmental Geology
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    • v.22 no.3
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    • pp.207-219
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    • 1989
  • Eight under 2 micron size fractions of the montmorillonite from Jugjeonri area, Gyeongsanbug-do, were studied and then this result has been compared with data from Yongdongri area. Montmorillonites occurring at the same stratigraphic horizon in each area show limited variation in chemical composition, but shows some degree of differences in exchangeable cation compositions and total layer charges of montmorillonites from Jugjeonri to Yongdongri area. In general, samples from Jugjeonri show higher amount of exchangeable Na and layer charge due to relatively higher substitution of Mg for Al in octahedral sites than those from Yongdongri area. But Their dehydroxylation endothermic peaks of the samples from both areas are abnormal type with a small range of variation of peak temperature. This variation seems to reflect tetrahedral substitution of AI for Si for samples from Yongdongri whereas samples from Jugjeonri do not show shuch a tendency. However, samples from Jugjeonri proved to be relatively higher dehydroxylation peak temperatures than those of the other. DSC data for sample from Jugjeonri also show that divalent-cation saturated montmorillonite have relatively a higher endothermic heat capacities than monovalent-cation saturated one as shown in previous work. Two different morphologies of montmorillonites, honeycomb structure and closely packed intergrowth, by SEM were observed in samples from both areas but the later one is common. The scalloped type is relatively abundant in the sample from Yongdongri than the other. The dominant habit by TEM are irregularly shaped foliated aggregates and platy shaped particles. In general, foliated aggregates which are easy to disperse are relatively abundant in the samples from Jugjeon compared with those from Yongdongri area.

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