Australia: The Land Where Time Began

A biography of the Australian continent 

Greenland Ice Flow for the international Polar Year 2008-2009

According to Rignot & Mouginot for a variety of glaciological and geophysical analyses and modelling, a digital representation of the ice surface velocity is essential. In this Paper Rignot & Mouginot present a new, reference, comprehensive, high-resolution, digital mosaic of the motion of ice in Greenland that was assembled from satellite radar interferometry data that had been acquired by the Envisat Advanced Synthetic Aperture Radar (ASAR) during the International Polar Year 2008-2009, the Advanced Land Observation System (ALOS)’s Phase-Array L-band SAR (PALSAR) and the RADASAT-1 SAR that covers an area of 99 % of the ice sheet. The ALOS PALSAR date produced the best mapping performance as a result of higher levels of temporal coherence at the L-band frequency; but C-band frequency SAR data are affected less by the ionosphere. Various flow regimes are revealed that range from patterned enhanced flow in a few large glaciers in cold, low-precipitation areas of north Greenland; to diffuse, enhanced flow into many, narrow glaciers that are moving rapidly, in the warmer, high-precipitation sectors of northwest and southeast Greenland,  are revealed by the ice motion map. The 100 fastest glaciers, greater than 800 m/yr, drain an area of 66 % of the ice sheet, marine-terminating glaciers drain 88 % of Greenland, and the internal deformation over more than 50 % of the ice sheet is dominated by basal-sliding motion. Significant new constraints on ice flow modelling are provided by this view of ice sheet motion.

Sources & Further reading

1. Rignot, E. and J. Mouginot (2012). "Ice flow in Greenland for the International Polar Year 2008–2009." Geophysical Research Letters 39(11): n/a-n/a.