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Steady-state flow of solid CO2: preliminary results

Geophysical Research Letters

By:
, , and
DOI: 10.1029/1999GL008373

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Abstract

To help answer the question of how much solid CO2 exists in the Martian south polar cap, we performed a series of laboratory triaxial deformation experiments at constant displacement rate in compression on jacketed cylinders of pure, polycrystalline CO2. Test conditions were temperatures 150 < T < 190 K, hydrostatic confining pressures 5≤ P ≤40 MPa, and strain rates 4.5×10−8 ≤ ε ≤4.3×10−4 s−1. Most of the measurements follow a constitutive law of the form ε = Aσnexp(−Q/RT), where σ is the applied differential stress, R is the gas constant, and the other constants have values as follows: A = 103 86 MPa−ns−1, n = 5.6, and Q = 33 kJ/mol. Solid CO2 is markedly weaker than water ice. Our results suggest that the south polar cap on Mars is unlikely to be predominately solid CO2, because the elevation and estimated age of the cap is difficult to reconcile with the very weak rheology of the material.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Steady-state flow of solid CO2: preliminary results
Series title:
Geophysical Research Letters
DOI:
10.1029/1999GL008373
Volume
26
Issue:
23
Year Published:
1999
Language:
English
Publisher:
American Geophysical Union
Description:
4 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters
First page:
3493
Last page:
3496
Other Geospatial:
Mars