Ice motion of the Patagonian Icefields of South America: 1984-2014

We present the first comprehensive high-resolution mosaic of ice velocity of the Northern (NPI) and Southern Patagonian Icefields (SPI), from multiple synthetic aperture radar and optical data collected between 1984 and 2014. The results reveal that many of the outlet glaciers extend far into the central ice plateaus, which implies that changes in ice dynamics propagate far inside the accumulation area. We report pronounced seasonal to interannual variability of ice motion on Pio XI and Jorge Montt, a doubling in speed of Jorge Montt, a major slow down of O'Higgins, significant fluctuations of Upsala and a deceleration of San Rafael, which illustrate the need for sustained, continuous time series of ice motion to understand the long-term evolution of the rapidly thinning icefields. The velocity product also resolves major ambiguities in glacier drainage in areas of relatively flat topography illustrating the need to combine topography and flow direction to map drainage basins.