Skip to main content

A study of annual variations in the geomagnetic total intensity with special attention to detecting volcanomagnetic signals

Abstract

This paper investigates the cause of annual variations in the geomagnetic total intensity that are often seen especially in the volcanic areas. As a hypothesis of the cause, a model was proposed, in which such a change is produced by changes in the inhomogeneous magnetization of near-surface rocks due to temporal changes of the atmospheric temperature. This hypothesis was tested by field and laboratory experiments. First, amplitude and phase difference of annual variations in the total intensity and ground temperature data were determined by time series analyses. Considering thermal diffusion from the surface into the ground, the phase difference between the total intensity and temperature was converted to a characteristic depth, and then the amplitude of annual temperature variation at the depth was estimated. Finally, the observed total intensity variations were compared with the expected change on the basis of the temperature dependence of rock’s magnetization obtained by a laboratory experiment and the local magnetic anomaly obtained by a magnetic survey at each magnetometer site. A good agreement between the observed and expected changes was obtained, which strongly suggests that the hypothesis is correct. It was also shown that a correction of annual variations by using temperature data will enable us more accurate detection of volcanomagnetic signals.

References

  • Campbell, W. H., Introduction to Geomagnetic Fields, 290 pp., Cambridge Univ. Press, 1997.

  • Carslaw, H. S. and J. C. Jaeger, Conduction of heat in solids, 66 pp., Oxford Press, 1959.

  • Dampney, C. N. G., The equivalent source technique, Geophysics, 34, 39–53, 1969.

    Article  Google Scholar 

  • Davis, P. M., D. D. Jackson, C. A. Searls, and R. L. McPherron, Detection of tectonomagnetic events using multichannel predictive filtering, J. Geophys. Res., 86, 1731–1737, 1981.

    Article  Google Scholar 

  • Del Negro, C., F. Ferrucci, and R. Napoli, Retrieval of large volcanomagnetic effects observed during the 1981 eruption of Mt. Etna, Annali di Geofisica, 40, 547–562, 1997.

    Google Scholar 

  • Fukushima, H., T. Uwai, and M. Kuwashima, Magnetic observation in Aso volcano, Kak. Mag. Obs. Tec. Rep., 29, 127–134, 1990 (in Japanese).

    Google Scholar 

  • Hamano, Y., H. Utada, T. Shimomura, Y. Tanaka, Y. Sasai, I. Nakagawa, Y. Yokoyama, M. Ohno, T. Yoshino, S. Koyama, T. Yukutake, and H. Watanabe, Geomagnetic variations observed after the 1986 eruption of Izu-Oshima Volcano, J. Geomag. Geoelectr., 42, 319–336, 1990.

    Article  Google Scholar 

  • Imura, R., Geology of Kirishima volcano, Bull. Earthq. Res. Inst., Univ. Tokyo, 69, 189–209, 1994 (in Japanese with English abstract).

    Google Scholar 

  • Kagiyama, T., H. Utada, F. Masutani, M. Yamaguchi, Y. Sasai, Y. Tanaka, and T. Hashimoto, A geomagnetic investigation of the 1991–1992 eruption of Shinmoe-dake crater of Kirishima volcano, Proc. CA Symp., 279–296, 1992 (in Japanese).

    Google Scholar 

  • Masutani, F. and T. Kagiyama, Geomagnetic observations in Kirishima volcano, Tech. Res. Rep. Earthq. Res. Inst., Univ. Tokyo, 1, 18–22, 1996 (in Japanese).

    Google Scholar 

  • Merrill, R. T., M. W. McElehinny, and P. L. McFadden, The magnetic field of the Earth: paleomagnetism, the core, and the deep mantle, pp. 531, Academic Press, 1996.

  • Mueller. R. J. and M. J. S. Johnston, Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974–1995, Phys. Earth Planet. Inter, 105, 131–144, 1998.

    Article  Google Scholar 

  • Neki, M., A study on annual variations in the geomagnetic total intensity data observed in volcanic areas, M.Sc. Thesis, Univ. Tokyo, pp. 59, 1999 (in Japanese).

  • Neki, M., T. Kagiyama, F. Masutani, N. Osada, and H. Munekane, Observation of volcanic activity by ARGOS system, Bull. Volcanol. Soc. Japan, 43, 167–172, 1998 (in Japanese).

    Google Scholar 

  • Neel, L., Some theoretical aspects of rock magnetism, Adv. Phys., 4, 191–243, 1949.

    Article  Google Scholar 

  • Ohno, M., Paleomagnetic study of volcanic rocks of Younger Izu-Oshima Group, M. Sc. Thesis, Univ. Tokyo, 85 pp., 1988 (in Japanese).

  • Ozima, M., T. Owada, and K. Toya, An investigation on seasonal changes in the site difference of the geomagnetic total intensity in volcanic areas, Kak. Mag. Obs. Tec. Rep., 29, 64–76, 1996 (in Japanese).

    Google Scholar 

  • Pozzi, J. P., J. L. Le Mouël, J. C. Rossignol, and J. Zlotnicki, Magnetic observations made on la Soufrier volcano (Guadeloupe) during the 1976–1977 crisis, J. Volcanol. Geotherm. Res., 5, 217–237, 1979.

    Article  Google Scholar 

  • Rikitake, T., A five-year plan for earthquake prediction research in Japan, Tectonophysics, 3, 1–15, 1966.

    Article  Google Scholar 

  • Sasai, Y., T. Shimomura, Y. Hamano, H. Utada, T. Yoshino, S. Koyama, Y. Ishikawa, I. Nakagawa, Y. Yokoyama, M. Ohno, H. Watanabe, T. Yukutake, Y. Tanaka, T. Yamamoto, K. Nakaya, S. Tsunomura, F. Muromatsu, and R. Murakami, Volcanomagnetic effect observed during the 1986 eruption of Izu-Oshima Volcano, J. Geomag. Geoelectr., 42, 291–318, 1990.

    Article  Google Scholar 

  • Tanaka, Y., Eruption mechanism as inferred from geomagnetic changes with special attention to the 1989–1990 activity of Aso volcano, J. Volcanol. Geotherm. Res., 56, 319–338, 1993.

    Article  Google Scholar 

  • Tanaka, Y., Volcanomagnetic effects on the Unzen volcano (1990–1992), J. Geomag. Geoelectr., 47, 325–336, 1995.

    Article  Google Scholar 

  • Tanaka, Y, H. Masuda, M. Kawamura, K. Ohchi, S. Kato, H. Baba, and T. Yoshino, Surveys of the geomagnetic total intensity with proton magnetometers on Aso volcano (1977), in Report of Joint Observations of Aso volcano, edited A. Kubotera, pp. 31–39, 1977 (in Japanese).

  • Yukutake, T., H. Utada, T. Yoshino, H. Watanabe, Y. Hamano, Y. Sasai, E. Kimoto, K. Otani, and T. Shimomura, Changes in the geomagnetic total intensity observed before the eruption of Oshima volcano in 1986, J. Geomag. Geoelectr, 42, 277–290, 1990a.

    Article  Google Scholar 

  • Yukutake, T., H. Utada, T. Yoshino, E. Kimoto, K. Otani, and T. Shimomura, Regional secular change in the geomagnetic field in the Oshima island area during a tectonically active period, J. Geomag. Geoelectr., 42, 257–275, 1990b.

    Article  Google Scholar 

  • Zlotnicki, J. and J. L. Le Mouel, Possible electrokinetic origin of large magnetic variations at LaFournaise volcano, Nature, 343, 633–636, 1990.

    Article  Google Scholar 

  • Zlotnicki, J., R. Verhille, J. P. Viode, J. C. Delmond, G. Simeon, and P. Guillement, Magnetic network on the Montagne Pelée volcano (Martinique, Lesser Antilles): A trial to discriminate volcanomagnetic signal, J. Geomag. Geoelectr, 38, 151–164, 1986.

    Article  Google Scholar 

  • Zlotnicki, J., J. L. Le Mouël, J. C. Delmond, C. Pambrun, and H. Delorme, Magnetic variations on Piton de la Fournaise volcano: volcanomagnetic signals associated with the November 6 and 30, 1987, eruptions, J. Volcanol. Geotherm. Res., 56, 281–296, 1993.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hisashi Utada.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Utada, H., Neki, M. & Kagiyama, T. A study of annual variations in the geomagnetic total intensity with special attention to detecting volcanomagnetic signals. Earth Planet Sp 52, 91–103 (2000). https://doi.org/10.1186/BF03351617

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03351617

Keywords

  • Annual Variation
  • Magnetic Anomaly
  • Swarm Activity
  • Unzen Volcano
  • Proton Magnetometer