Plate Recycling Driving Forces in Comparison on Terrestrial, Venusian and Martian Environments

Author(s)
Maria Gertrude Firneis, Johannes Leitner
Abstract

In this paper we report on our theoretical calculations of the driving forces of plate recycling (trench pull and ridge push) for Venusian, Martian and Terrestrial environments. The application of a 2D model of a thermal convection cell in a fluid heated from below and with the restriction to very large Prandtl numbers [1] and by neglecting inertia-terms in the momentum equations and further by neglecting the heating of the descending lithosphere by friction in the terrestrial planets have resulted in discrete values for the two forces. On Earth the ratio between ridge push and trench pull is 1:13, which means that trench pull is about 13 times as potent as ridge push and therefore forms the dominant driving force. On Venus this ratio has been calculated to be 0.7:1, so that in contrast to Earth trench pull is not able to be a potent power for active plate-tectonics [2], a result which corresponds well with the MAGELLAN radar data set. For planet Mars the recent surface investigations point out that at present plate-tectonics is not operative, but it seems to be reasonable that in earlier times episodes of plate-recycling have occurred. Our model calculations have confirmed this assumption. They show that when presuming liquid surface water to be present, a plate-tectonics-driving-force-scenario is working. For the present Martian environment the inbalance of trench pull and ridge push is a very good indicator for the lack of active plate-tectonics.

Organisation(s)
Department of Astrophysics
Journal
Bulletin of the American Astronomical Society
Volume
37
No. of pages
749
ISSN
0002-7537
Publication date
2005
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/e98b86bf-61df-4dc6-a824-a57f229a869f