Siegler, Matthew and Aharonson, Oded and Carey, Elizabeth and Choukroun, Mathieu and Hudson, Troy and Schorghofer, Norbert and Xu, Steven (2012) Measurements of thermal properties of icy Mars regolith analogs. Journal of Geophysical Research E, 117 (E3). Art. No. E03001. ISSN 0148-0227 http://resolver.caltech.edu/CaltechAUTHORS:20120411-103559909
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20120411-103559909
In a series of laboratory experiments, we measure thermal diffusivity, thermal conductivity, and heat capacity of icy regolith created by vapor deposition of water below its triple point and in a low pressure atmosphere. We find that an ice-regolith mixture prepared in this manner, which may be common on Mars, and potentially also present on the Moon, Mercury, comets and other bodies, has a thermal conductivity that increases approximately linearly with ice content. This trend differs substantially from thermal property models based of preferential formation of ice at grain contacts previously applied to both terrestrial and non-terrestrial subsurface ice. We describe the observed microphysical structure of ice responsible for these thermal properties, which displaces interstitial gases, traps bubbles, exhibits anisotropic growth, and bridges non-neighboring grains. We also consider the applicability of these measurements to subsurface ice on Mars and other solar system bodies.
|Additional Information:||© 2012 by the American Geophysical Union. Received 18 August 2011; revised 20 December 2011; accepted 20 December 2011; published 7 March 2012. We thank Julie Castillo, Doug Cobos, Michael Hecht, Gerard Kluitenberg, Kenneth Libbrecht, Michael Mellon, David Paige, Marsha Presley, Al Slavin, and Steven Wood for their useful discussions and Axel Schmidt for aid in measuring grain surface roughness, Karen Wacker for the construction of and insightful discussion in designing our thermal properties probe, and Hermann Engelhardt, Liz Carey, and Kenny Oslund for years of guidance and dedication in the lab. This work was supported by the Mars Fundamental Research Program. Part of this work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.|
|Subject Keywords:||Mars; ice; permafrost; regolith; thermal conductivity; thermal properties|
|Official Citation:||Siegler, M., O. Aharonson, E. Carey, M. Choukroun, T. Hudson, N. Schorghofer, and S. Xu (2012), Measurements of thermal properties of icy Mars regolith analogs, J. Geophys. Res., 117, E03001, doi:10.1029/2011JE003938|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||11 Apr 2012 20:23|
|Last Modified:||26 Dec 2012 15:03|
Repository Staff Only: item control page