The foundations of the Patagonian icefields
Johannes J. Fürst, David Farías-Barahona, N. Blindow, Gino Casassa, Guisella Gacitúa, Michèle Koppes, Emanuele Lodolo, Romain Millan, Masahiro Minowa, J. Mouginot, Michał Pętlicki, Eric Rignot, Andrés Rivera, Pedro Skvarca, Martin Stuefer, Shin Sugiyama, José Uribe, Rodrigo Zamora, Matthias Braun, Fabien Gillet‐Chaulet, Philipp Malz, Wolfgang Jens-Henrik Meier, Marius Schaefer
Abstract
Abstract The two vast Patagonian icefields are a global hotspot for ice-loss. However, not much is known about the total ice volume they store - let alone its spatial distribution. One reason is that the abundant record of direct thickness measurements has never been systematically exploited. Here, this record is combined with remotely-sensed information on past ice thickness mapped from glacier retreat. Both datasets are incorporated in a state-of-the-art, mass-conservation approach to produce a well-informed map of the basal topography beneath the icefields. Its major asset is the reliability increase of thicknesses values along the many marine- and lake-terminating glaciers. For these, frontal ice-discharge is notably lower than previously reported. This finding implies that direct climatic control was more influential for past ice loss. We redact a total volume for both icefields in 2000 of 5351 km 3 . Despite the wealth of observations used in this assessment, relative volume uncertainties remain elevated.