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

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


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

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.<br><br>

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.<br><br>


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