Forte, Alessandro M.; Peltier, W. Richard; Dziewonski, Adam M.; Woodward, Robert L.; Forte, Alessandro M.; Dept. Earth & Planet. Sci., Harvard University; Peltier, W. Richard; Physics Dept., University of Toronto; Dziewonski, Adam M.; Dept. Earth & Planet. Sci., Harvard University; Woodward, Robert L.; U.S.G.S., Albuquerque Seismological Lab., New Mexico