This research is to extend previous development of preliminary global maps of mantle Rayleigh wave attenuation at different periods, showing evidence for the existence of a strong attenuation in the depth range corresponding to the upper mantle low Q (high attenuation) zone. Data will be taken from 20 Geoscope (French) stations and several IRIS (NSF-sponsored) stations. The inversion will be performed in two ways: attenuation maps alone, and simultaneous inversion of attenuation and velocity maps. The resulting 3-dimensional models will provide new information on upper mantle temperature and viscosity distributions. The goal is to contribute new insight into convective processes in the upper mantle.
