Rapid changes in ice discharge from Greenland outlet glaciers

• Main Authors: Ian M. Howat, Ian R. Joughin, Ted A. Scambos
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: Greenland; glacier; Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.1108; http://cirrus.unbc.ca/454/lec/Howat2007.pdf

Using satellite-derived surface elevation and velocity data, we find major short-term variations in recent ice discharge and mass-loss at two of Greenland’s largest outlet glaciers. Their combined rate of mass-loss doubled in less than a year in 2004 and then decreased in 2006 to near the previous rates, likely due to fast re-equilibration of calving front geometry following retreat. Total massloss is a fraction of concurrent gravity-derived estimates, pointing to an alternative source of loss and the need for high-resolution observations of outlet dynamics and glacier geometry for sea-level rise predictions. The recent, dramatic increase in ice discharge from many of Greenland’s large outlet glaciers has upended the conventional view that variations in ice-sheet mass-balance are dominated on short timescales by variations in surface