Reconciling mantle attenuation-temperature relationships from seismology, petrology, and laboratory measurements

Reconciling mantle attenuation-temperature relationships from seismology, petrology, and laboratory measurements

Seismic attenuation measurements provide a powerful tool for sampling mantle properties. Laboratory experiments provide calibrations at seismic frequencies and mantle temperatures for dry meltfree rocks, but require 10210 extrapolations in grain size to mantle conditions; also, the effects of water and melt are not well understood. At the same time, body wave attenuation measured from dense bro...

From Global Mantle Wave Attenuation Measurements

We present the results of an analysis of global lateral variations in anelasticity of the upper mantle, as measured from very long period Rayleigh waves observed on the GEOSCOPE network. Four consecutive wave trains are used on each record to eliminate uncertainty on the amplitude at the source and to take into account, in a linear manner, focussing effects due to lateral variations in elastic ...

Constraints on Mantle Electrical Conductivity from Field and Laboratory Measurements

A global geomagnetic response function, sensitive to the average radial electrical conductivity structure of Earth’s mantle to depths of at least 1800 km, is obtained by averaging published, single-site response functions estimated at periods between 10 – 10 seconds from magnetic observatory records. Although the error bars on the global response function are mostly smaller than 5%, Parker’s D ...

Reconciling coulomb dissociation and radiative capture measurements.

We calculate the energy spectrum for 8B dissociation on a Pb target to all orders in the Coulomb and nuclear fields, and show that the slope of S17(E) obtained in previous analyses of Coulomb dissociation data is too steep, due to deficiencies in the conventional first-order analysis that was used. With a more complete theory that avoids the far-field approximation and includes E2, nuclear and ...

The lunar magma ocean: Reconciling the solidification process with lunar petrology and geochronology