Computer Science – Sound
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008jgre..11312010c&link_type=abstract
Journal of Geophysical Research, Volume 113, Issue E12, CiteID E12010
Computer Science
Sound
11
Planetary Sciences: Solid Surface Planets: Remote Sensing, Planetary Sciences: Solid Surface Planets: Volcanism (6063, 8148, 8450), Planetary Sciences: Solar System Objects: Mars
Scientific paper
Amazonis Planitia has undergone alternating episodes of sedimentary and volcanic infilling, forming an interleaved sequence with an upper surface that is very smooth at the kilometer scale. Earlier work interprets the near-surface materials as either young, rough lava flows or ice-rich sediment layers, overlying a basement comprising the Vastitas Borealis Formation and earlier Hesperian plains. Sounding radar profiles across Amazonis Planitia from the Shallow Radar (SHARAD) instrument on the Mars Reconnaissance Orbiter reveal a subsurface dielectric interface that increases in depth toward the north along most orbital tracks. The maximum depth of detection is 100-170 m, depending upon the real dielectric permittivity of the materials, but the interface may persist at greater depth to the north if the reflected energy is attenuated below the SHARAD noise floor. The dielectric horizon likely marks the boundary between sedimentary material of the Vastitas Borealis Formation and underlying Hesperian volcanic plains. The SHARAD-detected interface follows the surface topography across at least one of the large wrinkle ridges in north central Amazonis Planitia. This conformality suggests that Vastitas Borealis sediments, at least in this region, were emplaced prior to compressional tectonic deformation. The change in radar echo strength with time delay is consistent with a loss tangent of 0.005-0.012 for the column of material between the surface and the reflector. These values are consistent with dry, moderate-density sediments or the lower end of the range of values measured for basalts. While a component of distributed ice in a higher-loss matrix cannot be ruled out, we do not find evidence for a dielectric horizon within the Vastitas Borealis Formation that might suggest an abrupt change from an upper dry layer to an ice-rich lower deposit.
Biccari Daniela
Campbell Bruce
Carter Lynn
Egan Anthony
Orosei Roberto
No associations
LandOfFree
SHARAD radar sounding of the Vastitas Borealis Formation in Amazonis Planitia does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with SHARAD radar sounding of the Vastitas Borealis Formation in Amazonis Planitia, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and SHARAD radar sounding of the Vastitas Borealis Formation in Amazonis Planitia will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-969265