Shear-Wave Splitting in Central Europe to Test Mantle-Upwelling Anisotropy Model

Stanford University, Stanford CA

Investigators

Abstract

Abstract for proposal EAR0107080 (PH #20x) Title: Shear-wave splitting in central Europe to test mantle-upwelling anisotropy model PI's: Simon L. Klemperer, Goetz Bokelmann, and Norman Sleep, Stanford University There are a number of unresolved yet fundamental questions about the nature of mantle upwellings or "plumes". Specifically, can we distinguish the plume model, i.e., material upwelling from parts of the deeper mantle, from alternative models as a source for mantle hotspots? To help answer these questions, we will make measurements of shear-wave splitting for seismic waves that travel through the upper mantle. These measurements can illuminate the geometry of flow-related mantle deformation, since such deformation leads to seismic anisotropy--the cause of shear-wave splitting. We will then compare our data to those predicted by several different models of plume/lithosphere interaction. In particular, the "parabolic asthenospheric flow" model, which is consistent with measurements from around Hawaii and Yellowstone, will be critically tested by our data. Although these data may address regional problems such as whether there is a relation between Eifel magmatism and extension in the Rhine Graben, they more fundamentally have the ability to detect the existence of plumes, answering an outstanding question in the geosciences.