thumbnail

Variation of the 3-??m absorption feature on Mars: Observations over eastern Valles Marineris by the mariner 6 infrared spectrometer

Journal of Geophysical Research E: Planets

By:

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

A new approach for calibration of the shortest wavelength channel (1.8 to 6.0 ??m) of the Mariner 6 infrared spectrometer was derived. This calibration provides a new description of the instrument response function from 1.8 to 3.7 ??m and accounts for the thermal contribution to the signal at longer wavelengths. This allows the two segments from 1.8 to 6 ??m to be merged into a single spectrum. The broad water of hydration absorption spans these two segments and is examined in these merged spectra using a method of band integration. Unlike previous analyses which rely on ratios at two wavelengths, the integration method can assess the band strength independently from the albedo in the near infrared. Spectra taken over the eastern end of the Valles Marineris are examined for variations of the band-integrated value, and three distinct clusters are found. Within the estimated uncertainty, two clusters (both low and high albedo) have approximately the same integrated band depth. The third cluster (medium albedo) has an integrated band depth about 10% higher. This difference cannot be systematically attributed to either surface or atmospheric parameters and suggests variation in the amount of water either chemically or physically bound in surface materials. Approximately one-half of the high integrated band depth cluster is associated with chaotic terrain at the source of outflow channels, the other half occurs over lower inertia plains adjacent to chasmata. This suggests both surface physical properties and mineralogy as well as water in exchange with the atmosphere contribute to the 3-??m bound water absorption. copyright. Published in 1997 by the American Geophysical Union.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Variation of the 3-??m absorption feature on Mars: Observations over eastern Valles Marineris by the mariner 6 infrared spectrometer
Series title:
Journal of Geophysical Research E: Planets
Volume
102
Issue:
E4
Year Published:
1997
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Geophysical Research E: Planets
First page:
9097
Last page:
9107
Number of Pages:
11