A Complete Map of Greenland Ice Velocity Derived from Satellite Data Collected over 20 Years

• Published in: Journal of Glaciology
• Main Authors: Joughin, Ian, Smith, Ben E., Howat, Ian M.
• Format: Text
• Language: English
• Published: 2017
• Subjects: Article; Greenland; Ice Sheet
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6582972/; https://doi.org/10.1017/jog.2017.73

While numerous maps of Greenland ice flow velocity exist, most have gaps in coverage and/or accuracy is limited. We processed a large volume of synthetic aperture radar (SAR) and Landsat 8 imagery collected between 1995 and 2015 to produce a nearly complete map of ice flow velocity for Greenland at a far greater accuracy than most prior products. We evaluated the accuracy of this map by comparing it with a variety of measured and estimated velocities. For the slow-moving interior of the ice sheet, where estimates are determined from interferometric phase, the errors are ~2 m a(−1) or better. For coastal areas, where estimates are determined entirely from speckle- or feature-tracking methods, errors are 2–3 m a(−1), which is in good agreement with the estimated formal errors. Especially for the slow-moving majority of the ice sheet, this map provides an important source of data for numerous types of glaciological studies.