Provided by David Mohrig, Massachusetts Institute of Technology
Total Time = 1:12 (3.7 MB)
This movie is a time lapse of bar migration shot from a stationary balloon tethered over the river. Still photographs were not taken at regular intervals, so the movements of dune crests are not smooth. We show the video three times at increasing speed. It might be best to focus in on one of the crests and follow its movement through time.
At 39 seconds (10:41 AM), two people can be seen near the center of the picture (useful for scale).
REFERENCE: Mohrig, D., and Smith, J.D., 1996, Predicting the migration rates of subaqueous dunes: Water Resources Research, v. 32, no. 10, p. 3207-3217.