• Title/Summary/Keyword: geomagnetic survey

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A Study on The Geomagnetic Survey in Korea (우리나라 지자기측량에 관한 연구)

  • 최재화;조규전;김세걸;최윤수;윤홍식
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.9 no.1
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    • pp.1-15
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    • 1991
  • This paper is to aim to review the basic theory of geomagnetic survey and analize the field observation data (1980-1989) measured by Korea G S I. The magnetic Chart of Korea is mapped with use of the analized results and the principal scheme about Korea geomagnetic survey is furthermore proposed

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The Health Hazard of Geomagnetic Field in Dwellings (주거에서 지자기장의 위해성에 관한 기초연구)

  • Han, Jong-Koo;Park, Tong-So
    • KIEAE Journal
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    • v.5 no.1
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    • pp.43-49
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    • 2005
  • People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. One of the properties of the earth is that the earth has a magnetic field associated with it- the Geomagnetic field. The geomagnetic field is produced by a combination of crustal rocks, external electric current systems that surround the earth that surround the earth and currents induced in the outer layers of the earth by magnetic field variations. Human beings have evolved with the background of magnetic field, they are accustomed to living in its presence. Geopathic stress occurs at geopathic zones where the geomagnetic field is disturbed. Geopathic zones exhibit magnetic charges. Geopathic zones are characterized by variations in geomagnetism, for the geomagnetic field is not uniform but exhibits many highly localized distortions, some random, some fairly regular. These occur in geological faults, caves and underground water channel. Many research papers and experiments of the western countries indicates that the geomagnetic field affects the people and living organism in dwellings. Therefore, it is necessary to investigate the geomagnetic field and people's response in living space. In this study the Health Hazard of geomagneic field in dwelling are studied through literature survey of related science field.

The Evaluation of Geomagnetic Field of Detached Houses and It's effect on Residence (단독주택의 지자기장평가와 거주자에 미치는 건강에 관한 연구)

  • Han, Jong-Koo;Lee, Kyung-Hoi
    • KIEAE Journal
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    • v.1 no.1
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    • pp.27-33
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    • 2001
  • There are many research Papers and experiments indicating that the geomagnetic field affects the people and living organism. People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. Therefore. it is necessary to investigate the geomagnetic field and people's response in living space. In this study the vertical component(Z value) of geomagnetic field in detached houses was measured, evaluated by related evaluation criteria, compared with interview survey.

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The Importance and Effect of Geomagnetic Field in Dwelling Space (주공간에서 지자기장 중요성과 그 영향)

  • 한종구;장동민
    • Journal of the Korean housing association
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    • v.14 no.6
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    • pp.79-86
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    • 2003
  • People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. Many research papers and experiments indicates that the geomagnetic field affects the people and living organism. Therefore, it is necessary to investigate the geomagnetic field and people's response in dwelling space. In this study the Importance and Effect of Geomagnetic Field in dwelling space are studied through literature survey of related science field.

Effects of Underground Empty Spaces on the Geomagnetic Flux Density Distribution (지하의 빈 공간에 의한 지자기의 자속밀도분포)

  • Lee, Moon-Ho
    • Journal of the Korean Magnetics Society
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    • v.19 no.2
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    • pp.67-73
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    • 2009
  • The changes of geomagnetic flux density distribution on the ground surface by underground empty spaces had been investigated through the variations of the soil density and measuring heights. The geomagnetic flux density distributions were monitored for the surfaces of different density, sink-hole and tunnel by fluxgate-type magnetometer. The underground empty space and low soil density decreased the geomagnetic flux densities, which were decreased from the boundary of raw and low-density (empty) grounds, and showed the lowest value at the center of low-density (empty) ground. The decreases of geomagnetic flux density by underground empty spaces could be found at the surface with the tunnel located at 80 m underground. And, the underground defects of empty spaces, low density zone, fracture zone and sink holes could be monitored by the phenomena of this decreasing flux density.

A study on the Difference Arrow of GDS (Geomagnetic Depth Sounding) Survey using 2-D MT (Magneto-Telluric) Modeling (2차원 MT(Magneto-Telluric)모델링을 이용한 지자기 수직탐사(Geomagnetic Depth Sounding)에서의 차이 지시자의 연구)

  • 양준모;오석훈;이덕기;윤용훈
    • Economic and Environmental Geology
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    • v.35 no.6
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    • pp.567-573
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    • 2002
  • Two-dimensional MT (Magneto-Telluric) modeling is performed to verify the validity of difference arrow for GDS(Geomagnetic Depth Sounding) survey. The electromagnetic mutual coupling between the sea and in-land conductor is used as a criterion that judges the validity of difference arrow. In this study, the mutual coupling between them is examined according to the spatial distance between them and the period of magnetic variations. The difference arrow is valid for conductors located at surface which are far from the sea or when the long period is used, but the mutual coupling is weak for buried conductor in all the periods. However, when a conductor extends vertically down to the deep part, the validity of difference arrow is in doubt, since the strong mutual coupling influences up to the long period. Therefore, to remove the known conductor effect such as sea effect from the observed induction arrow, the mutual coupling between them must be examined and the caution must be exercised in interpreting the resultant difference arrow if mutual coupling between them is strong.

Magnetic anomaly in the southern part of the Yellow Sea (서해남부해역의 지자기 이상대 해석)

  • Kim, Sung-Bae;Choi, Sung-Ho;Suh, Man-Cheol
    • 한국지구물리탐사학회:학술대회논문집
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    • 2008.10a
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    • pp.85-92
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    • 2008
  • National Oceanographic Research Institute is carrying out an oceanographic survey for the entire sea areas around Korean Peninsula annually starting with the East Sea from 1996 by establishing a national oceanographic basic map survey plan for the sea areas under the jurisdiction of Korea, so this paper used the oceanographic geomagnetism data measured at the southern area of the Yellow Sea using 'Hae Yang 2000' in 1999, aiming at clarifying the cause of geomagnetic abnormality zone during the course of treating and analyzing the geomagnetic data. For treatment of magnetic data, we obtained electromagnetic force values and geomagnetic abnormality values around the investigated sea area through a process of searching and removal of bad data, correction of sensor positions, correction of magnetic field effects around the hull, correction of diurnal variation, normal correction, correction of cross point errors, etc. The electromagnetic force distribution around the investigated sea area was $49000\;{\sim}\;51600\;nT$, which is judged to be within the normal electromagnetic force intensity distribution range around the Yellow Sea. The isodynamic lines are distributed in Northeast-Southwest direction, and electromagnetic force values are increasing toward the northwest. The result of comparing the magnetic abnormality around the sea area among $124^{\circ}$ 49' 48" E, $35^{\circ}$ 10' 48" N $\sim$ $125^{\circ}$ 7' 48" E, and $35^{\circ}$ 33' 00" N sections with the elastic wave cross section and the result of modeling coincide well with the underground geological structure clarified from the existing elastic wave survey cross section. Therefore, it is judged that the distribution of magnetic force abnormality generally shows the effect pursuant to the distribution of the sedimentary basins in the Tertiary period and the bedrocks in the Cretaceous period which are well developed in the bottom of the sea.

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Geomagnetic Anomalies by Underground Fracture Zones and Vacant Spaces (파쇄대와 지하의 빈 공간에 의한 지자기이상)

  • Lee, Moon-Ho
    • Journal of the Korean Magnetics Society
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    • v.20 no.2
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    • pp.52-60
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    • 2010
  • The changes of magnetic flux density distribution and the degree of magnetic anomaly on the ground surface by underground fracture zones and empty spaces had been investigated through the variations of the measuring heights. The magnetic flux density distributions were monitored for the ground surfaces of fracture zones, empty spaces and tunnels by fluxgate-type magnetometer. The fracture zones showed the magnetic anomaly with (+) and (-) peak-pairs in the magnetic flux distribution measured at 0.15 m height from the ground surface, and this anomaly disappeared at the height of 1.15 m. The underground empty spaces and tunnels showed the decrease of magnetic flux densities, where the degree of this density decrease diminished with the increase of the underground depth. And, the existence and size of underground empty spaces, such as tunnels and sink holes, could be monitored by the phenomena of this decreasing flux density.

Electromagnetic Survey in Korea (한국의 전자탐사 현황)

  • Cho, Dong-Heng
    • Economic and Environmental Geology
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    • v.39 no.4 s.179
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    • pp.427-440
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    • 2006
  • Electromagnetic(EM) survey has been in use for over a half century as a standard routine for, mineral exploration in many parts of the world. But EM survey work and serious research effort were initiated in Korea only as late as in early 1980s, largely inspired by four pioneers who did their graduate studies in the U.S.A. in 1970s. Nevertheless domestic achievements in the field of EM survey are remarkable in the last two decades: the field operations and related interpretational skills appear to have reached a global standard, even compared with the most advanced in other countries, virtually in a whole spectrum of the method which includes magneto-tellurics(MT), Controlled Source Audio-frequency Magneto-tellurics(CSAMT), geomagnetic sounding, small loop survey systems, Very Low Frequency(VLF), Ground Penetrating Radar(GPR), time domain surveys, and noise analysis. Besides mineral exploration, EM survey has been applied in Korea to hydrogeology, geotechnical engineering, non-destructive investigation of structures, unexplored ordnance(UXO) investigation, environmental monitoring, and archaeological investigation as well. Now that original contributions of several Korean geophysicists are found even in new frontiers such as high-frequency EM survey, investigation in time-domain EM field for buried metal objects and structures, and also modem data inversion scheme, it is duly hoped that they make some technical breakthrough to unravel still entangled knots of EM survey method in a forseeable future.

Subsurface Geological Structure of the Southwestern Part of the Ogcheon Zone by Gravity and Magnetic Surveys (중력 및 자력탐사에 의한 옥천대 남서부의 지하 지질구조)

  • 김성균;오진용;안건상;김용준
    • The Journal of Engineering Geology
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    • v.8 no.3
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    • pp.285-296
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    • 1998
  • As a part of the study for understanding the deep geological structure of the Ogcheon Zone, both gravity and geomagnetic surveys are performed. A 70km survey line of which direction is nearly perpendicular to major faults in the southern tip of the Zone. The observed data are corrected and transformed into Bouguer and total magnetic intensity anomalies, respectively. Recent studies for petrology and geochemistry in the southwestern Ogcheon Zone in the vicinity of the survey line are reviewed for better interpretation. Both gravity and geomagnetic anomalies abruptly change around Janghung area, the southern boundary of the, Ogcheon Zone. This rapid increase of Bouguer anomaly around Janghung area can be explained by a deep seated normal fault with fairy large displacement between Precambrian gneisses and the denser intermediate plutonic rocks. It is believed that the fault acted an important role for the formation and evolution of the Ogcheon Zone. A pseudomagnetic intensity anomaly is calculated from the Bouguer anomaly assuming that the both anomalies are associated with the common source. From the origin of the survey line to the 50km point, the calculated anomaly coincides with observed magnetic anomaly. Whereas both anomalies show negative correlation in the outside 50km. From the residual Bouguer anomalies, the subterranean geological structure is provided through the iterative forward method. The initial model is obtained from informations about the surface geology as well as the results of the inverse method.

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