Campuses:

Morphological Instabilities, Oscillations, Fingers, Channels, and Multiple Equilibria in Mantle Upwelling, Volcanoes, Glaciers, and Oceans

Thursday, September 27, 2001 - 11:00am - 12:00pm
Keller 3-180
Jack Whitehead (Woods Hole Oceanographic Institution)
We review convections rolls, cells, patches of cells, and contrast them with global tectonic plates. This introduces the instability of temperature-dependent viscous flow as it enters a cold region. For one-dimensional flow, multiple equilibrium is found. With elasticity, oscillations are present. Laboratory experiments show oscillatory instability. Glacial surges and some earthquakes have similarities. Volatile presence also produces oscillations. Fingers form in channels and perhaps networks form in porous igneous flows. Multiple equilibrium flows and oscillations are found in models and in laboratory experiments with temperature and salinity. The chimney problem, hydraulic jumps and inertia. Mixing rate has an important and perhaps fundamental effect on global thermohaline transitions.