Recent aeolian erosion and deposition in the north polar plateau of Mars.
Citation:
Rodriguez, J.A.P., Tanaka, K., Langevin, Y., Bourke, M.C, Kargel, J., Christensen, P., Sasaki, S., Recent aeolian erosion and deposition in the north polar plateau of Mars., Mars: The International Journal of Mars Science and Exploration, 3, 2007, 29 - 41Download Item:
Abstract:
Background:
Planum Boreum, the north polar plateau of
Mars, displays four extensive low-albedo
regions covered with widespread se
dimentary deposits that are thick enough to partly or completely
suppress the signature of the residual water ice that forms the uppermost zone of the polar layered
deposits. These sedi
mentary deposits appear to
have a source primarily in a buried sedimentary layer
preferentially exposed along the wall
s and floors of some polar troughs.
The deposits extend and drape
over circum-polar dunes.
Method:
The data analyses in this research were conducted with Geographic Information Systems
(GIS) mapping tools. The followin
g data sets have been used:
(1)
Mars Odyssey (MO) Thermal Emission
Imaging System (THEMIS) summer north polar visibl
e light mosaics at 18 m/pixel and 32 m /pixel, as
well as 18 m/pixel visible multiband images (THEMI
S mosaic provided by P.H. Christensen and the
THEMIS Team, Arizona State U.),
(2)
Mars Express (MEX) High Resolution Stereo Camera (HRSC)
images at 10 m/pixel,
(3)
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) narrow-angle (NA;
>1.4 m/pixel) and a wide-angle
image mosaic, 64 pixels/degree,
(4)
Mars Reconnaissance Orbiter
(MRO) High Resolution Imaging Science Experiment (HiRISE) camera images at resolutions that range
from 31.8 cm/pixel (with 1 x 1 binning) to 63.5 cm/pixel (with 2 x 2 binning),
(5)
MGS Mars Orbiter
Laser Altimeter (MOLA) 512 pixels/degree digital elevation models, and
(6)
MEX OMEGA Vis/IR imaging
spectrometer. False color maps have been derived fro
m OMEGA data in which all three color planes are
proportional to albedo (0.1: level 0, 0.45: level 255)
. The red plane scales inversely with the fraction of
the area covered by ice, derived from the band stre
ngth at 1.5 ?m (factor of 0 for 30% fractional ice
coverage within the pixel, factor
of 1 for ice-free pixels). The H
2
O ice spectral signatures have been
observed by OMEGA in November 2004, during early northern summer (Ls 109? to 114?). The incidence
at the time of observations was nearly optimal for such latitude regions (57.6?). Sampling on the
ground was 1.7 to 2 km.
Conclusion:
The most recent history of the north pola
r plateau of Mars includes highly dynamic
sedimentary processes involving large-scale wind-d
riven mass transfer from Planum Boreum towards
its periphery. The proposed polar
processes involved: (I) retreat along undulations within upper layered
deposits (ULD), thereby exposing
underlying dark sedimentary deposi
ts, (II) mobilization of these
deposits to form extensive dark mantles, which are water-ice free and that terminate in circum-polar
terrains, and (III) complete removal of these depo
sits leading to the exhu
mation of pre-existing troughs
Author's Homepage:
http://people.tcd.ie/bourkem4Description:
PUBLISHED
Author: BOURKE, MARY
Type of material:
Journal ArticleCollections
Series/Report no:
Mars: The International Journal of Mars Science and Exploration;3;
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