a r t i c l e i n f o The rapid expansion of high-spatial resolution optical sensors and imagery over the last decade presents exceptional opportunities for quantifying visible attributes of geomorphic systems. In this study, we detail a simple, robust methodology (ChanGeom) to extract continuous channel width and centerline datasets for single-thread channels using freely available high-spatia...

Analyses of lithology, organic-matter content, magnetic susceptibility, and pollen in a sediment core from Okpilak Lake, located in the northeastern Brooks Range, provide new insights into the history of climate, landscape processes, and vegetation in northern Alaska since 14,500 cal year BP. The late-glacial interval ([11,600 cal year BP) featured sparse vegetation cover and the erosion of min...

In fluvial systems, organismic exposure to nonpoint source pollutants will fluctuate in frequency (exposure events), intensity (concentration), and duration. The reliance on lethal concentrations and static exposure in many laboratory studies does not adequately represent nor address exposure to in situ chemical plumes of fluvial habitats. To adequately address field exposure in a laboratory se...

because it is not possible to recognize the mechanism of cantilever failure in field studies, this type of common failure in riverbanks is investigated in the laboratory. for this purpose, two samples of susceptible soil that forms an overhanging block in riverbanks are used for physical model tests to determine their physical, chemical and mechanical characteristics. soil blocks of different d...

Introduction: The latitude dependent distribution [1-3] and non-uniform orientations [4-8] of young gullies on Mars suggest that their formation and modification are controlled by the activity of volatiles at or near the surface. Given the relative abundance of gullies and Mars' current thermal environment, CO 2 and H 2 O are the most likely candidates for contributing to gully evolution. Conte...

An estimated 229,000 m(3) of coal fly ash remains in the river system after dredging to clean-up the 2008 Tennessee Valley Authority (TVA) spill in Kingston, Tennessee. The ash is heterogeneous with clear, orange and black spheres and non-spherical amorphous particles. Combustion produces iron oxides that allow low field magnetic susceptibility (χ(LF)) and percent frequency dependent susceptibi...