• Title/Summary/Keyword: Integrated geology

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Investigation of Water Leakage in Seosan A-Region Sea Wall using Integrated Analysis of Remote Sensing, Electrical Resistivity Survey, Electromagnetic Survey, and Borehole Survey (원격탐사, 전기탐사, 전자기탐사 및 시추공영상의 융합적 분석을 통한 서산지역 방조제 누수구역 판별)

  • Hong, Seong-In;Lee, Dongik;Baek, Gwanghyun;Yoo, Youngcheol;Lim, Kookmook;Yu, Jaehyung
    • Economic and Environmental Geology
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    • v.46 no.2
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    • pp.105-121
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    • 2013
  • This study introduces integrated approach on detection of a leakage in a sea wall based on remote sensing, electric resistivity survey, electromagnetic survey, and borehole survey for the Seosan A-Region sea wall. The satellite temperature distribution from Landsat ETM+ data identifies water leakage distribution and period by analyzing temperature mixing patterns between sea water and fresh water. Electric resistivity survey provides both horizontal and vertical anomaly distributions over the sea wall showing below average electric resistivity. Electromagnetic survey(electrical conductivity survey) reveals the potential possible leakage areas with minimal background impact by comparing electrical conductivity values between high and low tides. Borehole image processing system confirmed the locations of anomalies identified from the other survey methods and distributions of vertical fracture zones. The integrated approach identified 41.7% of the sea wall being the most probable area vulnerable to water leakage and effectively approximated both horizontal and vertical distribution of water leakage. The integrated analysis of remote sensing, electric resistivity survey, electromagnetic survey and borehole survey is considered to be an optimal method in identifying water leakage distribution, period, and extent of fractures knowledged from the boreholes.

Case Study on the Mitigation of Dangerous Slope Considering the Value of Geoheritage (지질유산 가치를 고려한 위험비탈면 보존 방안 사례 연구)

  • Jeong, Jun-Ho;Kim, Seung-Hyun;Park, Byung-suk;Woo, Yong-Hoon;Kang, Yun-seok;Koo, Ho-bon;Son, Moon
    • The Journal of Engineering Geology
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    • v.30 no.1
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    • pp.71-84
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    • 2020
  • Various geological structures are found on the slope of Bangnim district in Pyeongchang, Gangwon-do, based on the Paleozoic Joseon Supergroup Limestone. The recumbent fold observed on the slope is a very rare geological structure that has not been found in Korea, and has important academic value in exploring the formation process of the Paleozoic geological structures in the Gangwon region. In this study, discussed the geological value of the geological structure observed on the slope of the road, and studied the management method of rockfall problem slopes. The state of development of recumbent folds has conservation value in geological scarcity and specificity. Preservation management measures should be prepared through the protection of slopes and measures to reduce of rockfall risks as geoheritage with an important value in geology science and education. Furthermore, it is expected to be preserved and utilized as a geopark.

P-Impedance Inversion in the Shallow Sediment of the Korea Strait by Integrating Core Laboratory Data and the Seismic Section (심부 시추코어 실험실 분석자료와 탄성파 탐사자료 통합 분석을 통한 대한해협 천부 퇴적층 임피던스 도출)

  • Snons Cheong;Gwang Soo Lee;Woohyun Son;Gil Young Kim;Dong Geun Yoo;Yunseok Choi
    • Geophysics and Geophysical Exploration
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    • v.26 no.3
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    • pp.138-149
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    • 2023
  • In geoscience and engineering the geological characteristics of sediment strata is crucial and possible if reliable borehole logging and seismic data are available. To investigate the characteristics of the shallow strata in the Korea Strait, laboratory sonic logs were obtained from deep borehole data and seismic section. In this study, we integrated and analyzed the sonic log data obtained from the drilling core (down to a depth of 200 m below the seabed) and multichannel seismic section. The correlation value was increased from 15% to 45% through time-depth conversion. An initial model of P-wave impedance was set, and the results were compared by performing model-based, band-limited, and sparse-spike inversions. The derived P-impedance distributions exhibited differences between sediment-dominant and unconsolidated layers. The P-impedance inversion process can be used as a framework for an integrated analysis of additional core logs and seismic data in the future. Furthermore, the derived P-impedance can be used to detect shallow gas-saturated regions or faults in the shallow sediment. As domestic deep drilling is being performed continuously for identifying the characteristics of carbon dioxide storage candidates and evaluating resources, the applicability of the integrated inversion will increase in the future.

Integrated Application Strategies for Natural Disaster Information (자연재해정보의 통합적 활용방안 연구)

  • Yeon, Young-Kwang;Han, Jong-Gyu;Chi, Kwang-Hoon;Ryu, Kun-Ho
    • Economic and Environmental Geology
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    • v.40 no.6
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    • pp.785-795
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    • 2007
  • Recently, the knowledge and use of information production and service in integrated information has been changing from intra-organizational to inter-organizational and even international. In particular, since natural disasters are complexly related, it is increasingly important to use integrated information from related areas in the reduction and prevention of such events. In this study, we suggest strategies for the use of integrated information from natural disasters based on that expanding need. This study analyzes information user surveys, the interrelated information technologies, trends, and case studies to determine user access to the information, the status of the information used, and the supply and distribution of that information. From the survey results, we can draw conclusions about the effectiveness of the strategies of integrated information used in domestic natural disaster information.

Tectonics, sedimentation, and magmatism of the Cretaceous Gyeongsang (Kyongsang) Basin, Korea: Integrated approach to defining basin history and event mineralization

  • Chang, Ryu-In;Park, Seon-Gyu;Meen, Wee-Soo;Lee, Sang-Yeol
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.27-31
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    • 2003
  • During the past decade, integrated stratigraphy has been effectively applied to many sedimentary basins to analyze stratigraphic response to tectonic evolution. This application has been beneficial to hydrocarbon exploration in the basins because it provides a better understanding of temporal and spatial relationships of hydrocarbon source and reservoir rocks as a function of basin evolution. Like the maturation, migration, and trapping of hydrocarbons, ore-forming processes in hydrothermal deposits may be causally linked to particular phases of basin evolution. Consequently, applying integrated stratigraphy to mineral exploration may be a logical and helpful approach to understanding ore-forming processes and predicting their occurrence, location, and origin. (omitted)

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Analysis of Rock Slope Stability by Using GIS in Mt. Keumsu Area (지구정보시스템을 이용한 금수산일대의 암반사면 안정성 평가)

  • 배현철
    • Economic and Environmental Geology
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    • v.33 no.1
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    • pp.77-88
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    • 2000
  • The goal of this study is to assess the spatial distribution of natural slopes and cutting slopes under would-be development. For this goal, a quantitative slope stability analysis method using GIS integrated with a computer program was developed. Through field investigations, the discontinuity parameters were collected such as orientation of discontinuity, persistence, spacing, JRC, JCS, and water depth. The distributions were interpolated from the ordinary kriging method in ARC/INFO GIS after variogram analysis. The layers showing all parameters needed for limit equilibrium analysis were constructed. The final layer using GIS works composed of 162,352 polygons, that is, unit slopes. The rock slope stability analysis program was coded by C++ language. This program can calculate geometrical vectors related to rock block failures using input orientation data and direction and dimension of strength to occur failure. Also, this can calculate shear strength of joints through empirical equations and quantitative factors of safety. This methodology was applied to the study area which is located in Jaecheon city and Danyang-gun of the northeastern Keumsu is about 135$km^2$. As a result, the study area was entirely stable but unstable, that is, factor of safety less than 1.0dominantly at the slopes near Keumsil, Daejangri, Keumsungmyun and Sojugol, Mt. Dongsan, Juksongmyun by the natural slope stability analysis. Assuming the cutting slope showing the same direction immediate, and quantitative analysis of factors of safety for a regional area could be conducted through GIS integrated with a computer program of limit equilibrium.

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제주 분지 올리고세층의 층서 및 퇴적환경

  • 김재호;이용일
    • 한국석유지질학회:학술대회논문집
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    • autumn
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    • pp.29-37
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    • 1999
  • Stratigraphic subdivision, correlation and depositional environments of Oligocene strata in the Cheju basin are studied using microfossils, wireline-log, trace elements from Geobuk-1, Okdom-1 and JDZ V-2 exploratory wells as well as seismic attributes. Application of these Integrated approaches is becoming increasingly an important tool in sedimentary and petroleum geology. The purpose of this study is to provide an integrated sequence-stratigraphic interpretation for petroleum system in the Cheju basin. During the last several years the Cheju basin has been studied for petroleum potential in terms of sequence stratigraphy. The strata assigned to be of the Early Miocene in the previous studies are reinterpreted to be of Oligocene in age. Depositional environments of these strata are also reinterpreted to have been influenced significantly by marine floodings. This interpretation is supported by the lines of evidence such as occurrences of abundant dinoflagellates and calcareous nannofossils, higher sulfur (1000-10000 ppm), TOC contents $(>1{\~}3{\%})$ and hydrogen index, and specific biomarkers such as dinostrane and $C_{30}$ 4-methyl steranes. Seismic facies, determined as a fairly continuous amplitude reflection, relatively parallel uniform strata, also provides a clue for recognizing marine transgressions during the Oligocene. Two 2nd--order stratigraphic cycles are observed in Oligocene strata based on well-log responses and the presence of microfossils. Each sequence comprises shallow marine deposits in the lower part and inner-outer neritic deposits in the upper part, thus showing a upward-deepening trend. In petroleum exploration point of view, the presence of marine strata would provide a better exploration potential for source rock and reservoir quality in the Cheju basin, offshore Korea.

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Mapping the water table at the Cheongju-Gadeok site of the Korea National Groundwater Monitoring Network using multiple geophysical methods

  • Ju, Hyeon-Tae;Sa, Jin-Hyeon;Kim, Ji-Soo
    • The Journal of Engineering Geology
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    • v.27 no.3
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    • pp.305-312
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    • 2017
  • The most effective way to distinguish subsurface interfaces that produce various geophysical responses is through the integration of multiple geophysical methods, with each method detecting both a complementary and unique set of distinct physical properties relating to the subsurface. In this study, shallow seismic reflection (SSR) and ground penetrating radar (GPR) surveys were conducted at the Cheongju-Gadeok site of the Korea National Groundwater Monitoring Network to map the water table, which was measured at 12 m depth during the geophysical surveys. The water table proved to be a good target reflector in both datasets, as the abrupt transition from the overlying unsaturated weathered rock to the underlying saturated weathered rock yielded large acoustic impedance and dielectric constant contrasts. The two datasets were depth converted and integrated into a single section, with the SSR and GPR surveys conducted to ensure subsurface imaging at approximately the same wavelength. The GPR data provided detailed information on the upper ~15 m of the section, whereas the SSR data imaged structures at depths of 10-45 m. The integrated section thus captured the full depth coverage of the sandy clay, water table, weathered rock, soft rock, and hard rock structures, which correlated well with local drillcore and water table observations. Incorporation of these two geophysical datasets yielded a synthetic section that resembled a simplified aquifer model, with the best-fitting seismic velocity, dielectric constant, and porosity of the saturated weathered layer being $v_{seismic}=1000m/s$, ${\varepsilon}_r=16$, and ${\phi}=0.32$, respectively.

Analysis of Slope Stability by Using Remote Sensing and GIS in Ichon Basin (원격탐사와 지구정보시스템 (GIS)을 이용한 이천분지의 사면안정평가)

  • Won, Jong Suck;Lee, Young-Hoon
    • Economic and Environmental Geology
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    • v.30 no.3
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    • pp.241-248
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    • 1997
  • In this study, Ichon basin is selected as study area and regional analysis of geological structure are done by using lineament analysis. The factors which affects slope stability, are chosen, and integrated to database using GIS (Geoscientific Information System). Landsat TM band 4, 5 and 7 are choosen and processed by various image enhancement technique to analyse the regional geological lineaments. Spatial distribution of lineament is analysed through lineament density map and study area can be divided the eight structural domains. Considering environmental geological characteristics of study area, rating and weighting of each factors for slope stability analysis are determined and spatial analysis of regional slope stability is examined through overlaying technique of GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Mt. Buksung, Mt. Daepo, Mt. Songrim and Mt. Yankak.

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