Seismic methods at the long wavelength limit detect the total seismic velocity anomaly X_off ?c where christliche partnervermittlung ?c is the change of the velocity of the recorded wave. If seismic velocity varies linearly with temperature over this range, the total velocity anomaly is proportional to ?T_downX_down. As a caveat, trace amounts of partial melt may well affect seismic velocity in the asthenosphere, so the coefficient to convert temperature variation to seismic velocity variation is not obvious. Linearization may even be inappropriate and the proportionality coefficient may vary with depth as the phase assemblage changes. Till et al. review these issuesplicated relationships between temperature and seismic velocity are beyond the scope of this paper.

van Wijk et al. presented models of downwellings at the edge of rifted thin lithosphere. Their models had T_? of ?57 and ?107 K within the range where stagnant-lid formalism is applicable. Their viscosity increased with depth along an adiabat, increasing by a factor of e per scale depth D_{? Leia mais}