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Abstract

Summary

Earthquakes are a source of vibration of the Earth that cause high-frequency variations (normal modes) of the geophysical fields such as Earth's gravity field and magnetic field. 0S2 is called the football mode as the deformed shape alternates between that of an American football and a pumpkin. For the spheroidal normal mode 0S2, we have five singlets. We investigate splitting of the fundamental spheroidal mode 0S2 based on analysis of geomagnetic variations during periods of strong earthquakes. In periods of 15 days after major earthquakes, in the absence of strong magnetic disturbances, it is possible to distinguish the fine structure of the basic spheroidal mode of the earth 0S2 in the geomagnetic variations. The estimated singlet frequencies of 0S2 are good agreement with theoretical ones computed for the Earth model 1066A. This indicates that the Earth's magnetic field is very sensitive to mechanical processes occurring in the Earth. Moreover, the received data confirm the fact that the Earth, for all the complexity of its structure, and the presence of geospheres that are very different in their properties, represents a single geophysical system consisting of constantly interacting geospheres and geophysical fields.

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/content/papers/10.3997/2214-4609.201901054
2019-06-03
2024-04-25

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References

  1. Suda, N., Nawa, K. and Fukao, Y.
    [1998] Earth's background oscillations. Science, 279, 2089–2091.
     [Google Scholar]
  2. Tanimoto, T.
    [2001] Continuous free oscillations: atmosphere-solid Earth coupling. Annual Review of Earth and Planetary Sciences, 29, 563–584.
     [Google Scholar]
  3. Bobova, V.P., Osypov, K.S., Savina, N.G., Vladimirsky, B.M. and Pudovkin, M.I.
    [1990] Probability of the seismic origin of long-period T = 1 - 4h variations of geomagnetic disturbances. Geomagnetism and Aeronomy, 30, 492–494.
     [Google Scholar]
  4. Alsop, L.E., Sutton, G.H., and Ewing, M.
    [1961] Free oscillations of the Earth observed on strain and pendulum seismographs. Journal of Geophysical Research, 66, 631–641.
     [Google Scholar]
  5. Benioff, H.V., Press, F. and Smith, S.W.
    [1961] Excitation of free oscillations of the Earth by earthquakes. Journal of Geophysical Research, 66, 605–619.
     [Google Scholar]
  6. Bolt, B.A., and Marussi, A.
    [1962] Eigenvibrations of the Earth observed at Trieste. Geophysical Journal of the Royal Astronomical Society, 6, 299–311
     [Google Scholar]
  7. Connes, J., Blum, P.A., Jobert, G. and Jobert, N.
    [1962] Observation des oscillations propres de la Terre, Annales Geophysicae, 18, 260–268.
     [Google Scholar]
  8. Ness, N.F., Harrison, J.C., and Slichter, L.B.
    [1961] Observations of free oscillations of the Earth. Journal of Geophysical Research, 66, 621–629.
     [Google Scholar]
  9. Marple, S. and Lawrence, Jr.
    [1987] Digital spectral analysis with applications, Prentice-Hall, Englewood Cliffs, New Jersey.
     [Google Scholar]
  10. Widrow, B. and Stearns, S.D.
    [1985] Adaptive signal processing, Prentice Hall, Englewood Cliffs, New Jersey.
     [Google Scholar]
  11. Dahlen, F.A. and Sailor, R.V.
    [1979] Rotational and elliptical splitting of the free oscillations of the Earth, Geophysical Journal of the Royal Astronomical Society, 58, 609–623.
     [Google Scholar]
  12. Dahlen, F.A. and Tromp, J.
    [1998] Theoretical global seismology. Princeton University Press, Princeton.
     [Google Scholar]
  13. Gilbert, F. and Dziewonski, A.M.
    [1975] An application of normal mode theory to the retrieval of structural parameters and source mechanism from seismic spectra. Philosophical Transactions of the Royal Society A, 278, 187–269.
     [Google Scholar]
  14. Crossley, D.J. and XuS.
    [1998] Analysis of superconducting gravimeter data from Table Mountain, Colorado. Geophysical Journal International, 135, 835–844.
     [Google Scholar]
  15. Van Camp, M.
    [1999] Measuring seismic normal modes with the GWR C021 superconducting gravimeterPhysics of the Earth and Planetary Interiors, 116, 81–92.
     [Google Scholar]
  16. Kennet, B.L. and Woodhouse, J.H.
    [1978] On high-frequency spheroidal modes and the structure of upper mantle. Geophysical Journal of the Royal Astronomical Society, 55, 441–455.
     [Google Scholar]
  17. Woodhous, J.H.D., Gardini, D. and Li, X.D.
    [1986] Evidence for inner core anisotropy from free oscillations. Geophysical Research Letters, 13, 1549–1552.
     [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201901054
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Study of the Splitting of the Football Mode 0S2 in Geomagnetic Variations
Conference Proceedings 2019, 1 (2019); https://doi.org/10.3997/2214-4609.201901054
/content/papers/10.3997/2214-4609.201901054
/content/papers/10.3997/2214-4609.201901054
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