Routine Monitoring of Changes in the Columbia Glacier, Alaska, with Synthetic Aperture Radar

Abstract

This study focuses on the use of spaceborne Synthetic Aperture Radar (SAR) from the European Remote Sensing Satellite (ERS-1) and the Canadian RADARSAT satellite to monitor retreating glaciers, specifically the Columbia Glacier, and the hazards caused by their recession on a routine basis. The Columbia Glacier is an important tidewater glacier to monitor because of its present rapid retreat, its generation of icebergs, and its vicinity to oil-tanker traffic in and out of the Port of Valdez, Alaska. We have established routine monitoring of the Prince William Sound area using SAR aboard the Canadian RADARSAT on a semi-weekly basis. To demonstrate the use of this data, four ERS-1 and seven RADARSAT SAR images from 1992 to 1998 are used in this study to monitor the long-term retreat of the Columbia Glacier. A loss of 17.7±0.2 square kilometers is measured from 1992 to 1997, with 38.4% of this change occurring from 1993 to 1994. Also, hazards such as icebergs are monitored in near real-time. SAR is an efficient and cost-effective means of monitoring glaciers, where cloud cover and logistical costs and difficulties hamper other data-collection efforts. These data are available to U.S. Government users and would be of benefit to the Prince William Sound region if used operationally.