HR: 0800h
AN: P11B-0547    [Abstracts]
TI: Radar Stratigraphy of Ice on Earth and Mars: What are we Missing? An Evaluation of Multiple Radars and Processing Techniques.
AU: * Holt, J W
EM: jack@ig.utexas.edu
AF: Institute for Geophysics, Jackson School of Geosciences, University of Texas, 10100 Burnet Rd., Austin, TX 78758, United States
AU: Blankenship, D D
EM: blank@ig.utexas.edu
AF: Institute for Geophysics, Jackson School of Geosciences, University of Texas, 10100 Burnet Rd., Austin, TX 78758, United States
AU: Corr, H F
EM: HFJC@bas.ac.uk
AF: British Antarctic Survey, High Cross, Maddingly Road, Cambridge, CB3OET, United Kingdom
AU: Plaut, J J
EM: plaut@mail.jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AU: Safaeinili, A
EM: ali.safaeinili@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AB: Radar sounding has been used for decades on Earth to map sub-ice topography, yet we are only beginning to fully make use of the information contained within the radar-detected, ice-internal layering. This internal layering serves as a guide to estimate accumulation rates and flow reorganization, to detect geothermal anomalies and to extrapolate ice core results over large regions. Radar layering in snow and ice on Earth is generally caused by variations in acidity due to deposits from volcanic eruptions, changes in ice crystal fabric, or variations in density (near the surface). Radar studies in Antarctica have been undertaken by a variety of means, most commonly airborne systems operating at 60 or 150 MHz, typically with 10 – 15 MHz bandwidths, but also sled-mounted systems generally operating in the 1 – 10 MHz range. The stratigraphy of icy deposits on Mars is also thought to hold important information about past climatic variations there and radar sounding has started to reveal new stratigraphic information to complement optical and spectral studies. Two orbital radar sounders are currently operating at Mars. MARSIS on Mars Express operates at 2 – 5 MHz, while SHARAD on Mars Reconnaissance Orbiter operates in the 15 – 25 MHz band. This is a tremendous advance over our ability to probe the subsurface of Mars just a few years ago; however, we don't know how much information we may be missing due to limited over-ice data at these frequencies on Earth. We therefore examine the impact of different wavelengths, bandwidths, and pulse types on the reconstruction of ice stratigraphy on both Earth and Mars by comparing data obtained from different radar systems over the same locations. Simulated results are also compared, as are the effects of data reduction schemes such as unfocused and focused synthetic aperture radar (SAR) processing.
DE: 0726 Ice sheets
DE: 0794 Instruments and techniques
DE: 6225 Mars
DE: 9310 Antarctica (4207)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting