Geological consequences of super-sized Earths
Article first published online: 11 OCT 2007
Copyright 2007 by the American Geophysical Union.
Geophysical Research Letters
Volume 34, Issue 19, October 2007
How to Cite
2007), Geological consequences of super-sized Earths, Geophys. Res. Lett., 34, L19204, doi:10.1029/2007GL030598., and (
- Issue published online: 11 OCT 2007
- Article first published online: 11 OCT 2007
- Manuscript Accepted: 22 AUG 2007
- Manuscript Revised: 20 JUL 2007
- Manuscript Received: 6 MAY 2007
- planetary evolution;
- plate tectonics
 The discovery of terrestrial-scale extrasolar planets, and their calculated abundance in the galaxy, has prompted speculation on their surface conditions and thermal structure. Both are dependent on the tectonic regime of a planet, which is itself a function of the balance between driving forces, and the resistive strength of the lithosphere. Here we use mantle convection simulations to show that simply increasing planetary radius acts to decrease the ratio of driving to resisting stresses, and thus super-sized Earths are likely to be in an episodic or stagnant lid regime. This effect is robust when associated increases in gravity are included, as the more dominant effect is increased fault strength rather than greater buoyancy forces. The thermo-tectonic evolution of large terrestrial planets is more complex than often assumed, and this has implications for the surface and conditions habitability of such worlds.