HR: 1340h
AN: ED13A-0716    [Abstracts]
TI: Rate Processes in Ocean Climate, Volcanoes, Earthquakes, and Glaciers: Their role in Multiple equilibria and Oscillations
AU: * Whitehead, J A
EM: jwhitehead@whoi.edu
AF: Woods Hole Oceanographic Institution, MS21, Department of Physical Oceanography, Woods Hole, MA 02543 United States
AB: Models of ocean circulation driven by temperature and salinity driving exhibit multiple equilibria. The temperature and salinity response times along with advection are factors in the simplest (classic) example of this. A laboratory model will be illustrated. Oscillations arise when a layer of fresh water is cooled faster than it can be replaced. Mixing of salty water is a factor. Laboratory examples and the simple mechanics of such a temperature to salinity oscillation will be showed. Volcanoes are unsteady because of many factors, but the simplest factor is probably that flow resistance increases as flow decreases due to cooling. This arises because the cooling time is smaller than the excursion time of a material parcel, so that magma stiffens before escaping. Oscillations arising from this feature are illustrated and a laboratory example described. Likewise, earthquakes and glacial surges exhibit such oscillations. Time scales are associated with temperature changes, grain size alterations, fluid migration etc. Again a simplified laboratory model will be described.
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 6605 Education
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 1030 Geochemical cycles (0330)
DE: 1620 Climate dynamics (3309)
SC: Education and Human Resourcese [ED]
MN: 2004 AGU Fall Meeting