Seismic imaging from ambient seismic noise.

123 Pages·2008·21.53 MB·French

by  Nikolai Shapiro

1965-30
9th Workshop on Three-Dimensional Modelling of Seismic Waves
Generation, Propagation and their Inversion
22 September - 4 October, 2008
Seismic imaging from ambient seismic noise
Nikolai Shapiro
Institut de Physique du Globe de Paris
France
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[email protected]
Studying the Earth's interior based on
Studying the Earth's interior based on
correlations of ambient seismic noise
correlations of ambient seismic noise
Nikolai Shapiro
Institut de Physique du Globe de Paris, France
“9th Workshop on Three-Dimensional Modeling of Seismic
Wave Generation, Propagation and their Inversion”
ICTP, Trieste, Italy, September 26, 2008.
Collaborators:
Michel Campillo, Florent
Brenguier, Mike Ritzwoller,
Laurent Stehly, Matthieu
Landes, Anatoly Levshin,
Yingjie Yang, Morgan
Moschetti, Misha Barmin,
Greg Bensen, Fan-Chi Lin
More information in publications at: http://www.ipgp.jussieu.fr/~nshapiro
Recommendations for reading
Bensen, G.D., M. H. Ritzwoller, M. P. Barmin, A. L. Levshin, F. Lin, M. P. Moschetti, N. M. Shapiroand Y. Yang, 2007. Processing seismic ambient
noise data to obtain reliable broad-band surface wave dispersion measurements, Geophys. J. Int., 169, 1239–1260 doi: 10.1111/j.1365-
246X.2007.03374.x.
Brenguier, F, M. Campillo, C. Hadziioannou, N. M. Shapiro, R. M. Nadeau, E. Larose, 2008. Postseismic Relaxation Along the San Andreas Fault at
ParkfieldfromContinuous Seismological Observations, Science, 321, 1478-1481.
Brenguier, F., N.M. Shapiro, M. Campillo,V. Ferrazzini, Z. Duputel, O. Coutant, and A. Nercessian, 2008. Towards forecasting volcanic eruptions
using seismic noise, Nature Geosciences, 1, doi:10.1038/ngeo104, 126-130.
Campillo, M. & Paul, A., 2003. Long-range correlations in the diffuse seismic coda,Science,299,547–549.
Derode, A., Larose, E., Tanter, M., de Rosny, J., Tourim, A., Campillo, M. & Fink, M., 2003. Recovering the Green’s function from field-field cor
relations in an open scattering medium,J. acoust. Soc. Am.,113,2973–2976.
Gouédard, P., L. Stehly, F. Brenguier, M. Campillo, Y. Colin de Verdière, E. Larose, L. Margerin, P. Roux, F. J. Sánchez-Sesma, N. M. Shapiro, and
R. L. Weaver, 2008. Cross-correlation of random fields: mathematical approach and applications, Geophysical Prospecting, 56, 375–393,
doi:10.1111/j.1365-2478.2007.00684.
Larose, E., Derode, A., Campillo, M. & Fink, M., 2004. Imaging from one- bit correlations of wideband diffuse wavefields, J. Appl. Phys., 95, 8393–
8399.88–105.
Sabra, K.G., Gerstoft, P., Roux, P., Kuperman, W.A. & Fehler, M.C., 2005a. Extracting time-domain Green’s function estimates from ambient seismic
noise,Geophys. Res. Lett.,32,L03310, doi:10.1029/2004GL021862.
Sabra, K.G., Gerstoft, P., Roux, P., Kuperman, W.A. & Fehler, M.C., 2005b. Surface wave tomography from microseism in southern California,
Geophys. Res. Lett.,32,L14311, doi:10.1029/2005GL023155.
Shapiro, N.M. & Campillo, M., 2004. Emergence of broadband Rayleigh waves from cor relations of the ambient seismic noise, Geophys. Res. Lett.,
31,L07614, doi:10.1029/2004GL019491.
Shapiro, N.M., Campillo, M., Stehly, L. & Ritzwoller, M.H., 2005. High resolution surface wave tomography from ambient seismic noise, Science,
307,1615–1618.
Shapiro, N.M., Ritzwoller, M.H. & Bensen, G.D., 2006. Source location of the 26 sec microseism from cross cor relations of ambient seismic noise,
Geophys. Res. Lett.,33,L18310, doi:10.1029/2006GL027010.
Snieder, R., 2004. Extracting the Green’s function from the cor relation of coda waves: a derivation based on stationary phase, Phys. Rev. E, 69,
046610.
Wapenaar, K., 2004. Retrieving the elastodynamic Green’s function of anarbitrary inhomogeneous medium by cross cor relation, Phys. Rev. Lett., 93,
254301, doi:10.1103/PhysRevLett.93.254301.
Weaver, R.L. & Lobkis, O.I., 2001a, Ultrasonics without a source: Thermal fluctuation cor relation at MHz frequencies, Phys. Rev. Lett., 87,
doi:10.1103/PhysRevLett.87.134301.
Weaver, R.L. & Lobkis, O.I., 2001b. On the emergence of the Green’s function in the cor relations of a diffuse field, J. acoust. Soc. Am., 110, 3011–
3017.
Weaver, R.L. & Lobkis, O.I., 2004. Diffuse fieldsin open systems and theemergence of the Green’s function,J. acoust. Soc. Am.,116,2731–2734.
Outline
1. Introduction
2. Extraction of surface waves from correlations of random wavefields
1. How it works
2. Regional seismic coda
3. Teleseismic coda
4. Ambient seismic noise
3. Noise based surface-wave tomography
1. Reminder of earthquake based surface-wave tomography
2. Noise data processing and noise-based dispersion
measurements
3. Examples: California, Western US, Europe
4. Noise based seismic monitoring
5. Origin of low-frequency seismic noise
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“traditional” seismological methods are based on point-like “deterministic” sources
(earthquakes, explosions)
continuous background seismic oscillations excited atmosphere, ocean and/or
human activity are generally categorized as “seismic noise” and ignored
“traditional” sources are either not optimally distributed in space and time
(earthquakes) either expensive (explosions)
deterministic seismic waves can be extracted from ambient seismic noise:
• empirical synthesis of seismic waves in absence of earthquakes and explosions
• seismic imaging
• continuous monitoring
Evolution of seismological observations
Traditional approach:
analogical seismology
• no high quality continuous records
• principal products:
bulletins and catalogs of seismic
events
• remaining records are considered as
“noise”
Travel-time measurements and inversions
Evolution of seismological observations
Modern reality:
digital seismology: continuous records
high quality