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Surface Deformation and Behavior of Magma Activity Using EDM

EDM을 활용한 지표변화율과 마그마 활동 양상 변화 연구

  • Yun, Sung-Hyo (Department of Earth Science Education, Pusan National University) ;
  • Lee, Jeong-Hyun (Institute of Environmental Studies, Pusan National University)
  • 윤성효 (부산대학교 지구과학교육과) ;
  • 이정현 (부산대학교 환경연구원)
  • Received : 2012.12.17
  • Accepted : 2013.01.31
  • Published : 2013.03.31

Abstract

Measuring the distance between benchmarks placed on a volcano tens to thousands of meters apart can sometimes pinpoint where and when magma is rising toward the surface. Rising magma will sometimes push overlying rocks upward or shove them aside. In either case, one part of the volcano may actually move horizontally relative to another part from as little as a few millimeters to as much as several tens of meters. The challenge in measuring such changes with an electronic distance meter is putting benchmarks in the right places and making frequent measurements between pairs of benchmarks. An electronic distance meter is an instrument that both sends and receives an electromagnetic signal. Depending on the distance between the EDM and reflector, the wavelength of the returned signal will be out of phase with the transmitted signal. The instrument compares the phase of the transmitted and received signals and measures the phase difference electronically. There is a wide range of EDM capabilities in range and precision, but for volcano monitoring purposes, short-range (less than 10 km) to medium-range (less than 50 km) EDM's are typically used. Short-range EDM's transmit and receive the near visible infrared part of the electromagnetic spectrum for measuring distances with an accuracy of about 5 mm.

화산체 위에서 수 km 또는 십 수 km 떨어진 거리에 위치한 수준점 사이의 거리 측정은 때때로 마그마가 지표로 상승할 때, 그 시기와 장소를 정확하게 나타낼 수 있다. 지표로 상승하는 마그마는 그 상부 암층을 상방으로 밀어 올리거나 또는 화산체의 정상부를 옆으로 밀어내기도 하다. 어떤 경우이든 화산체의 특정한 한 지점이 다른 지점에 비교하여 수 mm에서 수 십 m 이상으로 수평으로 움직일 수 있다. 전자거리측정장치인 광파측거의(EDM)를 통한 이러한 변화의 측정에 대한 시도는 적절한 장소에서 수준점들을 설정하고 이들 수준점들을 짝을 이루어 수시로 측정하는 것이다. 광파측거의는 전자기파 신호를 보내고 수신하는 장비이다. 광파측거의와 반사경 사이의 거리에 따라 되돌아오는 신호의 주파수는 전송된 신호와 위상차를 나타낼 것이다. 전송된 신호와 수신된 신호의 위상을 비교하여 전자적으로 위상차로부터 거리를 측정한다. 측정범위와 정밀도에 따라 광파측거의의 종류는 다양하다. 화산모니터링의 목적으로 단거리(10 km 이내) 광파측거의와 중거리(50 km 이내) 광파측거의가 일반적으로 사용되고 있다. 단거리 광파측거의는 전자기 스펙트럼의 가시 적외선에 가까운 영역을 전송하고 수신하면서 5 mm 이내의 정확도를 가지고 있다. 본 연구에서는 지금까지 알려진 광파측거의의 특성과 작동 원리, 국외 화산지역의 지표 변화율 측정 실례를 알아보고, 백두산에서의 지표면 변형 측정에 활용 가능한 기법을 기술하였다.

Keywords

References

  1. Abidin, H.Z., 1998, Monitoring the volcano deformation using repeated GPS surveys: Experiences and plans. Workshop on Advances in GPS Deformation Monitoring, Perth, Australia, 24-25 September, 18, 29p.
  2. Akimichi, T., Keiichi, F., Toshiki, S. and Sei, I., 2010, Atmospheric correction in EDM by using the JMA numerical weather model: Application to measurement at Asamayama volcano. The volcanological society of Japan, 55, 41-51.
  3. Brantley, S.R. and Topinka, L., 1984, Volcanic studies at the U.S. Geological Survey's David A. Johnston Cascades Volcano Observatory, Vancouver, Washington. Earthquake Information Bulletin, 16, 41-120.
  4. Chadwick, W.W., Iwatsubo, E.Y., Swanson, D.A. and Ewert, J.W., 1985, Measurements of slope distances and vertical angles at Mount Baker and Mount Rainier, Washington, Mount Hood and Crater Lake, Oregon, and Mount Shasta and Lassen Peak, California, 1980-1984. U.S. Geological Survey Open-File Report 85-205, 96p.
  5. Heliker, C.H., Griggs, J.D., Takahashi, T.J. and Wright, T.L., 1986, Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory. Earthquakes and Volcanoes, 18, 3-69.
  6. Iwatsubo, E.Y. and Swanson, D.A., 1992a, Methods used to monitor deformation of the crater floor and lava dome at Mount St. Helens, Washington. U.S. Geological Survey Bulletin, 1966, 53-68.
  7. Iwatsubo, E.Y. and Swanson, D.A., 1992b, Trilateration and Distance-Measuring Techniques Used at Cascades and Other Volcanoes. U.S. Geological Survey Bulletin, 1966, 103-114.
  8. Iwatsubo, E.Y., Topinka, L. and Swanson, D.A., 1992, Slope-Distance Measurements to the Flanks of Mount St. Helens, Late 1980 through 1989. U.S. Geological Survey Bulletin, 1966, 85-94.
  9. Jackson, P., Shepherd, J.B., Robertson, R.E.A. and Skerritt, G., 2012, Ground deformation studies at Soufriere Hills Volcano, Montserrat I: Electronic distance meter studies. Geophysical Research Letters, 25, 3387-3541.
  10. Lipman, P.W., Moore, J.G. and Swanson, D.A., 1981, Bulging of the north flank before the May 18 eruption; Geodetic data. U.S. Geological Survey Professional Paper, 1250, 143-156.
  11. Lockwood, J.P., Dvorak, J.J., English, T.T., Koyanagi, R.Y., Okamura, A.T., Summers, M.L. and Tanigawa, W.R., 1987, Mauna Loa 1974-1984; A decade of intrusive and extrusive activity. U.S. Geological Survey Professional Paper, 1350, 537-570.
  12. Mogi, K., 1958, Relations between the eruptions of various volcanoes and the deformations of the ground surfaces around them. Bulletin of Earthquake Research Institute, 36, 99-134.
  13. Murakami, M., 2005, Magma plumbing system of the Asama volcano inferred from continuous measurements of GPS. The volcanological society of Japan, 50, 347-361.
  14. Pingue, F., Troise, C., De Luca G., Grassi, V. and Scarpa. R., 1998, Geodetic monitoring of Mt. Vesuvius Volcano, Italy, based on EDM and GPS surveys. Journal of Volcanology and Geothermal Research, 82, 151-160. https://doi.org/10.1016/S0377-0273(97)00062-0
  15. Reger, J.M., 1996, Electronic distance measurement; An Introduction (Fourth Edition). Springer publication, 276p.
  16. Saito, E., Suto, S., Soya, T., Kazahaya, K., Kawanabe, I., Hoshizumi, H., Watanabe, K. and Endo, H., 1993, Geodetic monitoring using EDM before and during the 1991-1992 lava extrusion of Fugen-dake, Unzen Volcano, Kyushu, Japan. Bulletin of Geological Survey Japan, 44, 639-647.
  17. Suda, A., 1994, The Electromagnetic distance measuring instrument (Revised version). Morikita publication, 242p.
  18. Takagi, A., Fukui, K., Fujiwara, K., Ueda, Y., Iijima, S., Yamamoto, T., Takayuki, S., Kanno, T. and Hiroaki, K., 2005, Magma supply system of the 2004 eruption at Asama volcano estimated by crustal deformation data. The Volcanological Society of Japan, 50, 363-375.
  19. Takagi, A., Fukui, K., Shimbori, T. and Iijima, S., 2010, Atmospheric Correction in EDM by Using the JMA Numerical Weather Model: Application to Measurement at Asamayama Volcano. The Volcanological Society of Japan, 55, 41-51.
  20. Xu, J., Liu, G., Wu, J., Ming, Y., Wang, Q., Cui, D., Shangguan, Z., Pan, B., Lin, X. and Liu, J., 2012, Recent unrest of Changbaishan volcano, northeast China: A precursor of a future eruption? Geophysical Research Letters, 39, L16305, 7. doi:10.1029/ 2012GL052600.

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