Backwater Control of the Morphodynamics of Delta Growth

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Dr. John Shaw has been granted an NSF Earth Sciences postdoctoral fellowship to determine the effect of backwater flow on the depositional environment of river deltas. This research and education plan will take place at the University of Wyoming. The investigation will include laboratory-scale experiments which facilitate detailed measurement of delta properties, and outcrop study of ancient delta deposits exposed in Wyoming and Utah. By forcing experimental deltas to build under a rigid lid rather than a free surface, experiments will more closely resemble the low-slope deltas found at the mouth of the Mississippi River, as opposed than steeper-slope commonly realized in delta experiments. Dr. Shaw and interested undergraduate and graduate students will take morphologic and stratigraphic relationships drawn from the experimental analysis and apply them to rock outcrops of river deltas, with the goal of quantifying the size and shape of ancient delta systems. As part of the educational component of the plan, Dr. Shaw will create an river delta exhibit for the University of Wyoming Geological Museum, using ancient delta formations found in Wyoming and specifically in nearby Native American Reservations.River deltas support large human populations that benefit from productive ecosystems and transportation corridors, but are at risk from the hazards of storms and land loss associated with relative sea level rise. By investigating the effect of important variables (channel depth and slope) on delta morphology and stratigraphy, we will gain further knowledge regarding the depositional architecture of deltas, and better insight into how they will change in the future.