The influence of climate and tectonics on topography in the Hayes Range and its foothills

Abstract

Complex feedback exists among climate, tectonics, and glacial erosion in the creation of topography: climate influences glaciation; tectonics and glacial erosion modify topography; topography influences climate. The objectives of this study are to determine elevation distribution in the Hayes Range area of the central Alaska Range and to identify evidence for structural or erosional controls. I have used geospatial information systems (GIS) software to map mean elevation, calculate geomorphic indices from a digital elevation model (DEM), and characterize climatic, tectonic, and topographic patterns. Deformation, elevation, and erosion all increase southward within the range. In the northern part of the range, Quaternary doubly plunging anticlines and thrust faults uplift and deform a relict landscape. Despite the dominance of fluvial erosion, these elliptical topographic highs are tectonically controlled. Similar larger elliptical topographic highs are present farther into the range to the south, but Quaternary structures are more difficult to identify because of greater glaciation and erosion. The study area is one of high mean elevation, summits, slope, and relief. Topography in the Hayes Range exceeds what would be expected if glacial erosion kept pace with rock uplift. A young antiform in the Hayes Range can account for the rapid rock uplift needed.