Craig, H.Raynaud, D.Barnola, J.M.Chappellaz, J.Delmas, R.J.Lorius, C.Jouzel, J.Schwander, J.2022-11-232022-11-232022-11-231993-10-2910.1126/science.262.5134.763https://infoscience.epfl.ch/handle/20.500.14299/192640Gravitational separation in polar firntext::journal::journal article::review article