Horizontal displacement of ice in the Mer de Glace Glacier (Southern French Alps) between 08/23/2003 and 09/18/2003. The displacement field was obtained from two SPOT 5 satellite images, each with 2.5 m resolution. Arrows show the flow direction. Displacements below 2.5 m (the pixel size) are in blue. Displacements as high as 55 m (about 800 m/yr) are recorded over this 26-day period.