TOPOGRAPHY OF GLACIATED LANDSCAPES: EXPLORING THE SCALE-DEPENDENT INFLUENCE OF GLACIERS, RIVERS, AND TECTONICS IN COASTAL MAINE

Maine landscapes exhibit scale-dependent breaks in topographic form largely generated by combinations of glacial, fluvial, and tectonic processes. We use multi-scale, omni-variogram statistical methods to calculate the directional dependence and scale relevance of topography. Scale-dependent shifts in topographic anisotropy indicate that patterns of tectonism and lithology dominate at large scales, while glacial landforms tend to impose topographic anisotropy at smaller scales and follow an independent orientation pattern associated with the basal conditions of a continental ice sheet. Rivers tend to reflect the patterns associated with tectonics and lithology in the form of high order channels, while small tributaries reflect the directional dependence in glacial landforms, signifying that the fluvial regime in Maine is largely subsequent of other controls on landscape shape. Our findings indicate that the glacial history of Maine plays an important role in river channel morphology, while the tectonic history influences the large scale drainage network, and ultimately both influence the transport efficiency of surface runoff.