Determination of intrinsic attenuation in the oceanic lithosphere-asthenosphere system

Determining damping of our plates For plate tectonics to operate, a weaker layer called the asthenosphere must underlie the rigid lithospheric plates. Quantifying the difference in strength comes down to how much each layer attenuates energy. Takeuchi et al. exploited an ocean-bottom seismic network and seismic energy from the 2011 Japanese Tohoku-oki earthquake to quantify the attenuation in each layer (see the Perspective by Dalton). The attenuation of energy in the asthenosphere lined up with previous estimates, but the lithospheric attenuation was roughly one-fifth as strong as that predicted by some previous models. Science , this issue p. 1593 ; see also p. 1536