M.J. Hoffman, M. Perego, L.A. Andrews, S.A. Price, T.A. Neumann, J. Johnson, G.A. Catania, M.P. Lüthi
Widespread moulin formation during supraglacial lake drainages in Greenland.
Geophysical Research Letters
http://dx.doi.org/10.1002/2017GL075659A great model analysis of GPS measurements. Make sure you check out the movies (supplementary material), they are quite instructive.