The manual release of a dam in Texas in 2002 caused a large-scale flood event that carved a seven-metre-deep canyon, Lake Canyon Gorge, in just three days, according to a paper published online this week in Nature Geoscience. This contrasts with previous understanding that deep canyons, such as the Grand Canyon, USA, formed slowly, carved by rivers over millions of years.
Michael Lamb and colleague used this rare opportunity to analyse rapid formation of a deep river canyon. Using aerial photographs, topographic analyses and measurements of the rate and volume of flood discharge, the scientists documented the erosion processes involved.
These results provide useful insight into the processes that occurred during ancient megaflood events that may have formed deep canyons on both Earth and Mars.