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Gray, Harrison J ¹

¹ University of Colorado - Boulder

Obtaining quantitative sediment transport information, such as transport rates, virtual velocity, and characteristic scales, is an important goal of the hydrologic and geomorphic sciences. This information is useful for improving river infrastructure such as reservoirs and understanding the pace of landscape evolution as sediment loads change in response to environmental change. However, there are few means to obtain this information, either through resource-intensive field campaigns or in the rare case where a tracer such as mercury spills or radioisotope fallout, can be used to obtain this information. We explore the use of mineral luminescence as a means to obtain this sediment transport information via its use as a tracer. Luminescence is a property of minerals where electrons become trapped in crystal lattice defects when exposed to natural background radiation. These electrons escape when the crystal lattice is exposed to sunlight, heat, or high pressures. These physics have been used by the geoscience community for geochronology over the past 30 years. Here, I show that luminescence can potentially be used to extract sediment transport information by treating luminescence as an Eulerian quantity that can be treated with a statement of conservation of energy and a conservation of mass for sediment. My model satisfactorily reproduces the patterns of luminescence observed in rivers and produces sediment transport information on the same orders of magnitudes as other river systems. In this presentation, I show results from my current work measuring and modeling luminescence in systems where sediment transport information is already well known as a test of this potential new method. Initial results show that the basic predictions of the model are fulfilled in that theoretical spatial patterns are reproduced. Experiments to quantify luminescence removal rates is ongoing.