Powering Mercury's dynamo
- Creators
- Williams, J.-P.
- Aharonson, O.
- Nimmo, F.
Abstract
The presence of the global magnetic field of Mercury has implications for the interior structure of the planet and its thermal evolution. We use a thermal evolution model to explore the conditions under which excess entropy is available to drive a convective dynamo. The current state of the core is strongly affected by its sulfur concentration and the viscosity of the overlying mantle. A present-day dynamo is difficult to achieve. The minimum rate of entropy production required to drive a dynamo is attained in only the most optimistic models, and requires present-day mantle convection. An additional entropy source such as the addition of a radiogenic heat source in the core increases the probability of a present-day dynamo. Given the uncertainty, more specific characterization of the planet's interior and magnetic field is required to alleviate ambiguities in the original Mariner 10 observations.
Additional Information
© 2007 by the American Geophysical Union. Received 6 July 2007; revised 22 August 2007; accepted 8 October 2007; published 6 November 2007. We thank two anonymous reviewers for their comments. This work was supported by the California Institute of Technology through the O. K. Earl Postdoctoral Fellowship and the National Science Foundations Division of Earth Sciences (EAR) and the Astronomy and Astrophysics Research Grants program (AST-0709151).Attached Files
Published - grl23643.pdf
Supplemental Material - TableS1.pdf
Supplemental Material - TableS1.txt
Supplemental Material - grl23643-sup-0001-readme.txt
Files
Additional details
- Eprint ID
- 36936
- Resolver ID
- CaltechAUTHORS:20130215-080545476
- O. K. Earl Postdoctoral Fellowship
- AST-0709151
- NSF
- Created
-
2013-02-15Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field