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The effect of inertial accelerations on the higher frequency components of the signal from spring gravimeters
Author(s)
Language
English
Obiettivo Specifico
1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
2 / 182 (2010)
Publisher
Blackwell Publishing
Pages (printed)
772-780
Issued date
August 2010
Keywords
Abstract
Experimental and theoretical studies have shown that, due to the magma/gas dynamics in the upper part of a volcano’s plumbing system, gravity changes can develop over periods between a few tens of seconds and several hours. The mass transport, implied by certain fast-evolving volcanic processes, also constitute the source mechanism of seismic waves with frequencies over the lower limit of the seismic band. These seismic waves could affect the measuring system of spring gravimeters, that are increasingly used as continuously running devices to monitor and study active volcanoes. As a consequence, under some circumstances, the signal from a continuously running spring gravimeter will be the combination of the gravity field component and the inertial acceleration component, the latter due to the ground motion. In such cases, the inertial acceleration must be separated from the gravity signal to assess the amount of mass redistributed during the studied process. To achieve this separation, the frequency response curve of the spring gravimeter to inertial accelerations must be calculated, since it is not supplied by manufacturers. In this paper, we present a method to retrieve the above curve, using simultaneous recordings during the transit of teleseismic waves, of a LaCoste & Romberg D gravimeter and a Nanometrics Trillium 40 broadband seismometer, whose frequency response curve to ground acceleration is known a-priori. The use of teleseismic waves is particularly useful for our purpose since teleseisms are not associated with a local mass redistribution; the gravimeter will thus be affected only by the ground motion, making the above calculation possible. Our results show that, because of the instrumental damping, the effect of the inertial acceleration is reduced in the output signal from the gravimeter to 0.5 and 0.1 of its original value, at frequencies between 0.02 and 0.07 Hz, respectively. The robustness of the calculated frequency response curve is proven using independent simultaneous signals from gravimeter and broadband seismometer.
References
Achilli, V., Baldi, P., Casula, G., Errani, M., Focardi, S., Guerzoni, M., Palmonari, F. Raguní, G., 1995. A calibration system for superconducting gravimeters, J. Geod., 69 (2), 73-80.
Battaglia, M., Gottsmann, J., Carbone, D. Fernández, J.,2008. 4D volcano gravimetry Geophysics, 73(6), doi:10.1190/1.2977792.
Bormann, P., Liu, R., Xu, Z, Ren, K, Zhang, L Wendt, S, 2009. First Application of the New IASPEI Teleseismic Magnitude Standards to Data of the China National Seismographic Network, Bull. seism. Soc. Am., 99(3), 1868-1891, DOI: 10.1785/0120080010.
Carbone, D., Budetta, G. Greco, F., 2003a. Bulk processes some months before the start of the 2001 Mt Etna eruption, evidenced throughout microgravity studies, J. Geophys. Res., 108(B12) 2556, doi: 10.1029/2003JB002542.
Carbone, D., Budetta, G., Greco, F. Rymer, H., 2003b. Combined discrete and continuous gravity observations at Mt. Etna, J. Volcanol. Geother. Res., 2581, 1-13.
Carbone, D., Zuccarello, L., Saccorotti, G. Greco, F., 2006. Analysis of simultaneous gravity and tremor anomalies observed during the 2002– 2003 Etna eruption, Earth Planet. Sci. Lett., 245, 616- 629.
Carbone, D., Zuccarello, L. Saccorotti, G., 2008. Geophysical indications of magma uprising at Mt Etna during the December 2005 to January 2006 non-eruptive period, Geophys. Res. Lett., 35, L06305, doi:10.1029/2008GL033212.
Carbone, D., Jousset, P. Musumeci, C., 2009. Gravity ‘‘steps’’ at Mt. Etna volcano (Italy): Instrumental effects or evidences of earthquake-triggered magma density changes? Geophys. Res. Lett., 36, L02301, doi:10.1029/2008GL036179.
Chouet, B., 2003. Volcano seismology, Pure Appl. Geophys., 160, 739–788.
Chouet, B., Dawson, P. Martini, M., 2008. Shallow-conduit dynamics at Stromboli Volcano, Italy, imaged from waveform inversions, J. Geol. Soc. Lond., Special Publications, 307, 57-84 doi:10.1144/SP307.5.
Chouet, B., Dawson, P., Ohminato, T., Martini, M., Saccorotti, G., Giudicepietro, F., De Luca, G., Milana, G. Scarpa, R., 2003. Source mechanisms of explosions at Stromboli Volcano, Italy, determined from moment-tensor inversions of very-long-period data, J. Geophys. Res., 108(B1), 2019, doi:10.1029/2002JB001919.
Gadallah, M.R. Fisher, L., 2004. Applied Seismology: A Comprehensive Guide to Seismic Theory and Application, PennWell Corporation.
Gottsmann, J., Carniel, R., Coppo, N., Wooller, L., Hautmann, S. Rymer, H., 2007. Oscillations in hydrothermal systems as a source of periodic unrest at caldera volcanoes: Multiparameter insights from Nisyros, Greece, Geophys. Res. Lett., 34(7) L07307.
Kleusberg, A., 1989, Separation of inertia and gravitation in airborne gravimetry with GPS. In Developments in Four-Dimensional Geodesy, edited by F. K. Brunner and C. Rizos (Berlin: Springer-Verlag) , pp. 47-63.
Krüger, F. Ohrnberger, M., 2005. Tracking / the rupture of the Mw = 9.3 Sumatra earthquake over 1,150 km at teleseismic distance, Nature, 435, 937-939, doi:10.1038nature03696.
Longo, A., Barbato, D., Papale, P., Saccorotti, G. Barsanti, M., 2008. Numerical simulation of the dynamics of fluid oscillations in a gravitationally unstable, compositionally stratified fissure, J. Geol. Soc. Lond., Special Publications, 307, 33-44, doi: 10.1144/SP307.3.
Longo, A., Vassalli, M., Papale, P. Barsanti, M., 2006. Numerical simulation of convection and mixing in magma chambers replenished with CO 2-rich magma, Geophys. Res. Lett., 33, doi: 10.1029/2006GL027760.
Papoulis, A., 1991. Probability, Random Variables, and Stochastic Processes, 3Th edn, McGraw Hill.
Patanè, D., Di Grazia, G., Cannata, A., Montalto, P. Boschi, E., 2008. Shallow magma pathway geometry at Mt. Etna volcano, Geochem. Geophys. Geosys., 9, Q12021, doi:10.1029/2008GC002131.
Rymer, H., Murray, J.B., Brown, G.C., Ferrucci, F. McGuire, J., 1993. Mechanisms of magma eruption and emplacement at Mt. Etna between 1989 and 1992, Nature, 361, 439-441.
Saccorotti, G., Lokmer, I, Bean, C.J., Di Grazia, G. Patanè D., 2007. Analysis of sustained long-period activity at Etna Volcano, Italy, J. Volcanol. Geother. Res., 160, 340-354.
Sharma, P.V., 1986. Geophysical Methods in Geology, Elsevier, New York.
Torge, W., 1989. Gravimetry, pp. 465, Walter de Gruyter, Berlin.
VanRuymbeke, M., 1989. A calibration system for gravimeters using a sinusoidal acceleration resulting from a vertical periodic movement, J. Geod., 63(3), 223-236.
Varga, P., Hajósy, A. Csapó, G., 1995. Laboratory calibration of Lacoste–Romberg type gravimeters by using a heavy cylindrical ring, Geoph. J. Int., 120 (3), 745 - 757.
Welsh, P., 1967. The use of Fast Fourier Transform for the estimation of power spectra: a method based on time averaging over sort, modified periodoghrams, pp. 70-73, IEEE Trans. Audio & Electroacoust., AU-15.
Battaglia, M., Gottsmann, J., Carbone, D. Fernández, J.,2008. 4D volcano gravimetry Geophysics, 73(6), doi:10.1190/1.2977792.
Bormann, P., Liu, R., Xu, Z, Ren, K, Zhang, L Wendt, S, 2009. First Application of the New IASPEI Teleseismic Magnitude Standards to Data of the China National Seismographic Network, Bull. seism. Soc. Am., 99(3), 1868-1891, DOI: 10.1785/0120080010.
Carbone, D., Budetta, G. Greco, F., 2003a. Bulk processes some months before the start of the 2001 Mt Etna eruption, evidenced throughout microgravity studies, J. Geophys. Res., 108(B12) 2556, doi: 10.1029/2003JB002542.
Carbone, D., Budetta, G., Greco, F. Rymer, H., 2003b. Combined discrete and continuous gravity observations at Mt. Etna, J. Volcanol. Geother. Res., 2581, 1-13.
Carbone, D., Zuccarello, L., Saccorotti, G. Greco, F., 2006. Analysis of simultaneous gravity and tremor anomalies observed during the 2002– 2003 Etna eruption, Earth Planet. Sci. Lett., 245, 616- 629.
Carbone, D., Zuccarello, L. Saccorotti, G., 2008. Geophysical indications of magma uprising at Mt Etna during the December 2005 to January 2006 non-eruptive period, Geophys. Res. Lett., 35, L06305, doi:10.1029/2008GL033212.
Carbone, D., Jousset, P. Musumeci, C., 2009. Gravity ‘‘steps’’ at Mt. Etna volcano (Italy): Instrumental effects or evidences of earthquake-triggered magma density changes? Geophys. Res. Lett., 36, L02301, doi:10.1029/2008GL036179.
Chouet, B., 2003. Volcano seismology, Pure Appl. Geophys., 160, 739–788.
Chouet, B., Dawson, P. Martini, M., 2008. Shallow-conduit dynamics at Stromboli Volcano, Italy, imaged from waveform inversions, J. Geol. Soc. Lond., Special Publications, 307, 57-84 doi:10.1144/SP307.5.
Chouet, B., Dawson, P., Ohminato, T., Martini, M., Saccorotti, G., Giudicepietro, F., De Luca, G., Milana, G. Scarpa, R., 2003. Source mechanisms of explosions at Stromboli Volcano, Italy, determined from moment-tensor inversions of very-long-period data, J. Geophys. Res., 108(B1), 2019, doi:10.1029/2002JB001919.
Gadallah, M.R. Fisher, L., 2004. Applied Seismology: A Comprehensive Guide to Seismic Theory and Application, PennWell Corporation.
Gottsmann, J., Carniel, R., Coppo, N., Wooller, L., Hautmann, S. Rymer, H., 2007. Oscillations in hydrothermal systems as a source of periodic unrest at caldera volcanoes: Multiparameter insights from Nisyros, Greece, Geophys. Res. Lett., 34(7) L07307.
Kleusberg, A., 1989, Separation of inertia and gravitation in airborne gravimetry with GPS. In Developments in Four-Dimensional Geodesy, edited by F. K. Brunner and C. Rizos (Berlin: Springer-Verlag) , pp. 47-63.
Krüger, F. Ohrnberger, M., 2005. Tracking / the rupture of the Mw = 9.3 Sumatra earthquake over 1,150 km at teleseismic distance, Nature, 435, 937-939, doi:10.1038nature03696.
Longo, A., Barbato, D., Papale, P., Saccorotti, G. Barsanti, M., 2008. Numerical simulation of the dynamics of fluid oscillations in a gravitationally unstable, compositionally stratified fissure, J. Geol. Soc. Lond., Special Publications, 307, 33-44, doi: 10.1144/SP307.3.
Longo, A., Vassalli, M., Papale, P. Barsanti, M., 2006. Numerical simulation of convection and mixing in magma chambers replenished with CO 2-rich magma, Geophys. Res. Lett., 33, doi: 10.1029/2006GL027760.
Papoulis, A., 1991. Probability, Random Variables, and Stochastic Processes, 3Th edn, McGraw Hill.
Patanè, D., Di Grazia, G., Cannata, A., Montalto, P. Boschi, E., 2008. Shallow magma pathway geometry at Mt. Etna volcano, Geochem. Geophys. Geosys., 9, Q12021, doi:10.1029/2008GC002131.
Rymer, H., Murray, J.B., Brown, G.C., Ferrucci, F. McGuire, J., 1993. Mechanisms of magma eruption and emplacement at Mt. Etna between 1989 and 1992, Nature, 361, 439-441.
Saccorotti, G., Lokmer, I, Bean, C.J., Di Grazia, G. Patanè D., 2007. Analysis of sustained long-period activity at Etna Volcano, Italy, J. Volcanol. Geother. Res., 160, 340-354.
Sharma, P.V., 1986. Geophysical Methods in Geology, Elsevier, New York.
Torge, W., 1989. Gravimetry, pp. 465, Walter de Gruyter, Berlin.
VanRuymbeke, M., 1989. A calibration system for gravimeters using a sinusoidal acceleration resulting from a vertical periodic movement, J. Geod., 63(3), 223-236.
Varga, P., Hajósy, A. Csapó, G., 1995. Laboratory calibration of Lacoste–Romberg type gravimeters by using a heavy cylindrical ring, Geoph. J. Int., 120 (3), 745 - 757.
Welsh, P., 1967. The use of Fast Fourier Transform for the estimation of power spectra: a method based on time averaging over sort, modified periodoghrams, pp. 70-73, IEEE Trans. Audio & Electroacoust., AU-15.
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