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Determining dislocation Love numbers using satellite gravity mission observations
Earth, Planets and Space volume 58, pages 497–503 (2006)
Abstract
This paper presents a new approach to calculate dislocation Love numbers using observations of a satellite gravity mission (e.g. GRACE). The necessary condition is that the co-seismic potential change be sufficiently large to be detected by the gravity mission. Co-seismic deformations for each spherical harmonic degree n are decoupled. Therefore, dislocation Love numbers of degree n can be determined independently. The determinable maximum harmonic degree n depends on the seismic size, source type, magnitude, and the accuracy of a satellite gravity mission. For an arbitrary seismic source, all four types of dislocation Love numbers can be determined using data from only one seismic event because all deformation components are involved together. Only the concerned dislocation Love numbers can be computed for any one of the four types of sources. To prove the validity of the method proposed in this study, a simulation test is carried out by considering a similar case to the 2004 Sumatra earthquake (Mw 9.1). Results show that the method works well and guarantee the accuracy.
References
Ammon, C. J., J. Chen, H. Thio, et al., Rupture process of the 2004 Sumatra-Andaman Earthquake, Science, 308, 1133–1139, 2005.
Chao, B. F., Geodesy is not just for static measurements any more, Eos, Transactions, American Geophysical Union, 84, 145–156, 2003.
Chao, B. F. and R. S. Gross, Changes in the Earth’s rotation and low-degree gravitational field induced by earthquakes, Geophys. J. R. Astr. Soc., 91, 569–596, 1987.
Chao, B. F., V. Dehant, R. S. Gross, R. D. Ray, D. A. Salstein, M. M. Watkins, and C. R. Wilson, Space geodesy monitors mass transports in global geophysical fluids, Eos, Transactions, American Geophysical Union, 81, 247–250, 2000.
Dziewonski, A. M. and D. L. Anderson, Preliminary Reference Earth Model, Phys. Earth Planet. Inter., 25, 297–356, 1981.
Gilbert, F. and A. M. Dziewonski, An application of normal mode theory to the retrieval of structural parameters and source mechanisms from seismic spectra, Phil. Trans. R. Soc. London A, 278, 187–269, 1975.
Gross, R. S. and B. F. Chao, The gravitational signature of earthquakes, in Gravity, Geoid, and Geodynamics 2000, edited by M. G. Sideris, pp. 205–210, IAG Symposia Vol. 123, Springer-Verlag, New York, 2001.
Heiskanen, W. H. and Z. Moritz, Physical Geodesy, Freeman, San Francisco, 1967.
Khan, S. A. and O. Gudmundsson, GPS analyses of the Sumatra-Andaman Earthquake, EOS, Transactions, American Geophysical Union, 86(9), 2005.
National Research Council, NAS, Satellite Gravity and the Geosphere, edited by J. O. Dickey, Washington, D.C., 1997.
Okubo, S., Reciprocity theorem to compute the static deformation due to a point dislocation buried in a spherically symmetric Earth, Geophys. J. Int., 115, 921–928, 1993.
Okubo, S., W. Sun, T. Yoshino, T. Kondo, J. Amagai, H. Kiuchi, Y. Koyama, R. Ichikawa, and M. Sekido, Far-Field Deformation due to Volcanic Activity and Earthquake Swarm, Vistas for Geodesy in the New Millennium, edited by J. Adam and K. P. Schwarz, International Association of Geodesy Symposia, Volume125, 518–522, 2002.
Sun, W. and S. Okubo, Surface potential and gravity changes due to internal dislocations in a spherical earth—I. Theory for a point dislocation, Geophys. J. Int., 114, 569–592, 1993.
Sun, W. and S. Okubo, Co-seismic Deformations Detectable by Satellite Gravity Missions—a Case Study of Alaska (1964, 2002) and Hokkaido (2003) Earthquakes in the Spectral Domain, J. Geophys. Res., 109(B4), B04405, doi:10.1029/2003JB002554, 2004a.
Sun, W. and S. Okubo, Truncated Co-seismic Geoid and Gravity Changes in the Domain of Spherical Harmonic Degree, Earth Planets Space, 56, 881–892, 2004b.
Tamisiea, M. E., E. W. Leuliette, J. L. Davis, and J. X. Mitrovica, Constraining hydrological and cryospheric mass flux in southeastern Alaska using space-based gravity measurements, Geophys. Res. Lett., 32(20), L20501, 10.1029/2005GL023961.
Tapley, B. D., S. Bettadpur, J. C. Ries, P. F. Thompson, and M. M. Watkins, GRACE Measurements of Mass Variability in the Earth System, Science, 305(5683), 503–505, DOI:10.1126/science.1099192, 2004.
Wahr, J., M. Molenaar, and F. Bryan, Time variability of the Earth’s gravity field: Hydrological and oceanic effects and their possible detection using GRACE, J. Geophys. Res., 103, 30205–30230, 1998.
Watkins, M. M., W. M. Folkner, B. F. Chao, and B. D. Tapley, The NASA EX-5 Mission: A laser interferometer follow-on to GRACE, IAG Symp. GGG2000, Banff, July, 2000.
Xu, H. and F. Jiang, Transformation of spherical harmonic expressions of gravity anomaly, ACTA Geodetica et Cartographica Sinica, 7, 252–260, 1964.
Yamanaka, Y., Off west coast of northern Sumatra, Earthquake information centre seismological note No. 161, Earthquake Res. Instit., Univ. Tokyo. (http://www.eri.u-tokyo.ac.jp/sanchu/Seis.Note/2004/EIC161e.html), 2004.
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Sun, W., Okubo, S. & Sugano, T. Determining dislocation Love numbers using satellite gravity mission observations. Earth Planet Sp 58, 497–503 (2006). https://doi.org/10.1186/BF03351946
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DOI: https://doi.org/10.1186/BF03351946