Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4685478 | Geomorphology | 2011 | 10 Pages |
Granule ripples at Great Sand Dunes National Park and Preserve (GSDNPP) were observed using inexpensive digital timelapse cameras over a 70-day period in winter 2010–2011. The ripples migrated during a handful of discrete events — visible ripple movement occurred on only 11 days during the observation period. The movement conditions are documented with hourly and 15-minute records from two nearby weather stations, and by a cup anemometer at the site itself. During the most prominent movement episode, when local winds averaged ~ 10 m/s, ripples of several sizes were observed simultaneously and a reciprocal relationship of ripple size and propagation speed was seen, with small (~ 10 cm) ripples moving at ~ 1.4 cm/min, and larger (~ 80 cm) ripples at ~ 0.15 cm/min. Ripple sizes and morphologies evolve throughout the observation period.
Research highlights► Timelapse imagery shows wind ripple migration in action over several weeks. ► Instrumentation is inexpensive and simple to set up. ► Movement rates of several different sized ripples are measured at the same time. ► Wind statistics for the Great Sand Dunes site are presented.