IGPP Seminar Series

Polar Wandering During the Early History of Mars: Paleomagnetic Evidence and Implications

by Dr. Lon Hood
Lunar and Planetary Laboratory, University of Arizona


Major internal redistributions of mass within Mars, especially the formation and growth of the Tharsis gravity and topography anomaly, would have caused significant reorientations of the rotation axis relative to the planet. Recent modelling of martian crustal magnetic anomalies indicates a location for the northern paleopole prior to the cessation of the core dynamo and the formation of Tharsis at 30 to 40 degrees latitude and in a longitude sector centered northwest of what is now Olympus Mons. This result is supported by independent studies of the rotational stability of Mars without Tharsis, which suggest a paleopole location in the same region. If verified, this evidence for true polar wander would have implications for the assignment of basic climatic regimes (polar, temperate, tropical) experienced by ancient terranes during the early history of the planet when conditions were most favorable for the development of micro-organisms. Possible implications for the nature of martian crustal magnetic anomaly sources and the origin of east-west trending anomalies in the Southern Hemisphere are also discussed.
Tuesday, 14 February 2006
3845 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM