The first Physics Colloquium of the spring semester will be held on Thursday, January 31st at Noon in Tome 115.  Dr. Michelle Selvans from the National Air & Space Museum will present "Sleuthing on the Smallest Planet: What is the Relationship Between Tectonics and Crustal Thickness on Mercury?" Free pizza and everyone is welcome to attend!

Abstract:  Better understanding the tectonic history of the smallest terrestrial planet in our Solar System gives us insight into the full range of possibility for what solid planet surfaces are like, including 'Earth-like' exoplanets. Interior cooling and the resultant radial contraction of Mercury dominated the contribution to the contractional strain expressed by lobate scarps and high-relief ridges. The underlying large thrust faults should be randomly distributed over the surface if their formation was purely the result of global contraction, but instead these features appear to be concentrated in some regions and relatively deficient in others. I therefore ask the questions: What combination of stresses caused lobate scarps and high-relief ridges to form at the observed locations? Was mantle convection partly responsible for concentrating tectonic features? In this talk, I address the latter question in particular, using data from the MESSENGER mission.