Fractal analysis of topography and structure across the Appalachian foreland of West Virginia

Ashley Shannon Burns Douds, West Virginia University

Abstract

Fractal analysis was conducted on topographic relief and seismic reflection travel time data in the state of West Virginia to determine the potential influence of subsurface structure on surface topography. Seismic travel-times digitized from two east-west seismic profiles and topographic relief extracted in north-south and west-east directions from a 1:250,000 Digital Elevation Model (DEM) for the entire state were used in the analysis. A limited local study was also conducted of hand-drawn topographic profiles extracted from U.S.G.S. 1:24,000 topographic quadrangles over the Cottageville gas field in western West Virginia. This study also incorporated extraction of profiles in the same location from 1:24,000 DEMs of Cottageville and comparison of the fractal dimensions calculated from the two sources.;A mixture of positive and negative results were obtained from the analysis. No correlation was obtained between the fractal characteristics of the shallowest reflection event observed in the seismic lines and those of surface topography. In northern West Virginia there is relatively high correlation between the fractal dimension of topographic relief and the average fractal dimension of detached intervals above the Martinsburg shale. A short distance to the south this correlation drops to insignificant levels.;A weak but statistically significant negative correlation is observed between the fractal dimension of topographic relief and the average fractal dimension of deeper, sub-detachment, reflection events. In this case, the fractal dimension of topographic relief increases as those of deep reflection events decrease from east-to-west across the Appalachian Plateau Province.