I-AIM Interdisciplinary Seminar
(Institute for Applied and Interdisciplinary Mathematics)

3:10 PM Monday Oct. 1 in room SS 5017A

Professor Stephen Morris (University of Toronto Department of Physics)
"Some pattern formation experiments with a geophysical flavour"

I will present an overview of some recent Physics experiments which concerned dirty water, chemical plumes and cracking mud. If time permits, I will show some pleasant images of icicles.

Under "dirty water", we studied the front morphology of a turbidity current as it intruded into clean water. The front was unstable to a "lobe and cleft" pattern, which we were able to compare to recent theory and simulations. In the "chemical plume" experiment, we are studying rising plumes of buoyant solution in which the density change derives from a chemical reaction. The reaction occurs at a sharp, propagating front that converts the ambient solution into a lighter product without much temperature change. These plumes may have some analogy to chemically differentiated mantle plumes. Finally, under "cracking mud", we have been studying shrinkage fracture patterns in drying cornstarch slurries. These cracks mature into a roughly hexagonal columnar pattern that is closely analogous to the "columnar joints" observed in some lava flows.

Refreshments to follow in the Mathematics Lounge. All are welcome.