HR: 1340h
AN: P23B-1349    [Abstracts]
TI: The north polar lakes of Titan as observed by Cassini Radar
AU: * Mitchell, K L
EM: Karl.L.Mitchell@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 183-601 4800 Oak Grove Dr., Pasadena, CA 91101, United States
AU: Paillou, P
EM: philippe.paillou@obs.u-bordeaux1.fr
AF: Observatoire Aquitain des Sciences de l'Univers, UMR 5804 Observatoire Aquitain des Sciences de l'Univers, Floriac, UMR 5804, France
AU: Kirk, R L
EM: rkirk@usgs.gov
AF: U.S. Geological Survey, Flagstaff, 2255 N Gemini Dr., Flagstaff, AZ 86001, United States
AU: Lunine, J I
EM: jlunine@lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721, United States
AU: Stofan, E R
EM: estofan@starpower.net
AF: Proxemy Research Inc., 20528 Farcroft Lane, Laytonsville, MD 20882, United States
AU: Radebaugh, J
EM: jani.radebaugh@byu.edu
AF: Brigham Young University, Dept. of Geological Sciences, Provo, UT 84602, United States
AU: Wall, S D
EM: Stephen.D.Wall@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 183-601 4800 Oak Grove Dr., Pasadena, CA 91101, United States
AU: Hayes, A G
EM: hayes@gps.caltech.edu
AF: California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA 91125, United States
AU: Lopes, R M
EM: Rosaly.M.Lopes@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 183-601 4800 Oak Grove Dr., Pasadena, CA 91101, United States
AU: Stiles, B W
EM: Bryan.W.Stiles@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 183-601 4800 Oak Grove Dr., Pasadena, CA 91101, United States
AU: Ostro, S J
EM: ostro@reason.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 183-601 4800 Oak Grove Dr., Pasadena, CA 91101, United States
AU: Lorenz, R D
EM: Ralph.Lorenz@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, United States
AU: Wood, C A
EM: chuckwood@cet.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, United States
AU: Wood, C A
EM: chuckwood@cet.edu
AF: Wheeling Jesuit University, 316 Washington Avenue, Wheeling, WV 26003, United States
AU: Cassini Radar Team, T
EM: null@void
AF: Wheeling Jesuit University, 316 Washington Avenue, Wheeling, WV 26003, United States
AB: Over the course of a year, Cassini RADAR obtained Synthetic Aperture Radar images covering 69 percent of Titan's polar region north of 65 degrees; the region being 1.4E6 km3 in extent, greater than double the land area of the USA. We observe several hundred lakes with a range of morphological expression, including areally massive and morphologically distinctive "seas", covering ~15% of the polar region. Lakes are extremely radar dark, consistent with a lossy liquid hydrocarbon. Preliminary laboratory estimates suggest that loss tangents in the range 10E4 to 2x10E3 are reasonable, which implies that one can see through at least a few to many tens of m of liquids before the noise floor is reached, consistent with observed brightening towards many lake shores. North polar lake volumes are most likely in the 8E3 - 1.4E6 km3 range. Uncertainties will be reduced as more data, both image-based and experimental, are obtained but we can conclude with a high degree of confidence that hydrocarbon lakes on Titan are more voluminous than known terrestrial oil reserves; current estimates range from 2248 - 3896 billion barrels of oil (J. Hakes, 2000, Long Term World Oil Supply, Meeting of the Am. Ass. Pet. Geol., 18th April 2000, New Orleans, LA, http://www.eia.doe.gov/pub/oil_gas/petroleum/presentations/2000/long_term_supply.), hence 357 - 619 km3 . Small lakes often occupy steep-sided depressions, and although thermal and cryovolcanic origins cannot be completely ruled out, we are seeing growing geomorphologic evidence for dissolution chemistry, indicative of karst-like geology. The dichotomy between small lakes over slightly more than one half of the region, and seas on the other half, may be best explained by a topographic anomaly causing sub-surface flow of materials from the lakes to the seas. This may also explain observations by the Cassini ISS team (E. Turtle et al., in prep.) of a putative massive sea extending considerably further south than other observed north polar lakes.
DE: 2400 IONOSPHERE (6929)
DE: 2419 Ion chemistry and composition (0335)
DE: 9345 Large bodies of water (e.g., lakes and inland seas) (0746)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting