HR: 08:50h
AN: S11C-04    [Abstracts]
TI: Approaches for the Detection of Microseism Generating Regions from Space
AU: * Rodriguez, E
EM: ernesto.rodriguez@jpl.nasa.gov
AF: Jet Propulsion Laboratory/California Institute of Technology, MS: 300-319 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Kedar, S
EM: sharon.kedar@jpl.nasa.gov
AF: Jet Propulsion Laboratory/California Institute of Technology, MS: 300-319 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: Ocean microseisms have been suggested as a potential source for tomographic imaging of the Earth. An optimal tomographic approach requires that the source regions for ocean microseism generation be known. Longuet-Higgins (Philos. trans. R. Soc. London, 1950) has suggested that standing waves in the ocean are responsible for the generation of microseisms, so that a potential way of determining the regions responsible for microseism generation is the determination of which regions of the ocean exhibit standing wave activity. Although ocean standing waves have been observed and modeled in a laboratory setting, there is currently no remote sensing instrument capable of providing direct observations. In this paper, we consider remote sensing or modeling measurements which might provide observations indicative of potential standing wave activity. The first option, radar altimetry, provides a measurement of the significant wave height and, at lower resolutions, sea surface skewness. It is expected that non-linear interactions will result in a spatial modulation of the wave field and an increase of surface skewness. We review the accuracy of current ocean altimeters and conclude that, while these type of observations might be possible in the future, current altimeters do not have sufficient accuracy to retrieve the expected signals. An alternate approach is to use wave directional spectra to estimate the standing wave energy which might be observed. There are two potential sources for the estimation of directional wave spectra: wave action models (WAM's) or synthetic aperture radar (SAR). We review the capabilities of each of these measurements and conclude that they present a useful potential source for estimating regions of microseism generation. To test this conclusion, we present results of comparisons between SAR data collected off the California and WAM data with seismic data.
DE: 7294 Instruments and techniques
SC: Seismology [S]
MN: 2004 AGU Fall Meeting