DI51A-2618
Estimating the Buoyancy Field for Earth's Mantle Using Seismic and Mineralogical Models
Friday, 18 December 2015
Poster Hall (Moscone South)
Siavash Ghelichkhan1, Lorenzo Colli1, Thomas Chust2, Bernhard S. A. Schuberth3 and Nathan A Simmons4, (1)Ludwig Maximilians University of Munich, Munich, Germany, (2)Bayerisches Geoinstitut, Universitaet Bayreuth, Bayreuth, Germany, (3)Ludwig Maximilian University of Munich, Munich, Germany, (4)Lawrence Livermore National Laboratory, Atmospheric, Earth and Energy Division, Livermore, CA, United States
Abstract:
Many geophysical phenomena, such as mantle convection, dynamic topography, geoid undulations, and plate motions, arise as a balance between driving gravitational forces and resisting viscous stresses within the Earth's mantle. A good characterization of the present-day buoyancy field of the mantle would allow for tighter constraints on its viscosity. It is possible to derive an estimate for the present-day buoyancy field of the mantle using seismically-derived global tomographic models together with thermodynamically self-consistent models of mantle mineralogy. However, given the uncertainties affecting both seismic and mineralogical models, different choices can be made, which lead to different estimates. Here we explore some of the possible endmembers, looking at the different buoyancy structure they produce and the different implications they have for the dynamic Earth.
