HR: 0800h
AN: S31A-0266    [Abstracts]
TI: Lunar subsurface investigated from correlation of seismic noise
AU: * LAROSE, E
EM: eric.larose@ujf-grenoble.fr
AF: Laboratoire de Géophysique Interne et Tectonophysique (LGIT), BP 53, GRENOBLE, 38041 France
AU: KHAN, A
EM: amir@gfy.ku.dk
AF: Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, COPENHAGEN, 2100 Denmark
AU: NAKAMURA, Y
EM: yosio@utig.ig.utexas.edu
AF: Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Rd., AUSTIN, TX 78759-8500 United States
AU: Campillo, M
EM: Michel.Campillo@ujf-grenoble.fr
AF: Laboratoire de Géophysique Interne et Tectonophysique (LGIT), BP 53, GRENOBLE, 38041 France
AB: Correlation of Earth's seismic noise is an emerging and promising technique to image the subsurface. It was recently and successfully applied to surface wave tomography in California [Shapiro et al. Science (2005), Sabra et al. GRL (2005)], where the ocean and the atmosphere were found to be the most energetic sources of seismic noise. Is this technique applicable to other planets where such sources are not present? What kinds of information could this technique provide? This will be answered by carefully looking at the data collected on the moon by the Apollo 17 mission [Larose et al., GRL (2005)]. By correlating seismic noise recorded by four sensors placed on the Moon during the Apollo 17 mission, we have retrieved a well-defined dispersed Rayleigh wave pulse. Inversion of its group velocity provides a vertical velocity profile for the first 10m. The estimated 'signal-to-noise' ratio (SNR) of the retrieved Rayleigh wave train is strongly dependent on solar illumination, effectively making solar heating a source of seismic noise on the Moon. Finally, an original array technique was applied to determine the preferential direction of propagation of the seismic noise. This result suggests that in future planetary missions (Mars for instance) it is feasible to extract information on the internal structure of extraterrestrial objects by correlating seismic noise even when natural quakes are absent.
DE: 6094 Instruments and techniques
DE: 6250 Moon (1221)
DE: 7255 Surface waves and free oscillations
DE: 7260 Theory
SC: Seismology [S]
MN: Fall Meeting 2005