MAPPING ESKERS WITH LIDAR IN BUTLER AND LAWRENCE COUNTIES, PENNSYLAVANIA

The Jacksville esker in Butler County, PA is over a kilometer long and recognized as the best preserved esker in the state. It is located within the Wisconsinan terminal moraine complex. This study intended to map the disconnected segments of the esker over the area of two quadrangles with false color composite imagery. We suspect that esker vegetation contains lower amounts of chlorophyll than that of the vegetation surrounding the esker, based upon an apparent affinity of conifers for eskers, and hoped to use this differential reflection to map landforms. Results from this comparison, however, were inconclusive. Previous applications of this technique are reported to have been successful in Finland and Estonia. Failure of the technique in this instance may be related to greater fluvial incision of the landscape, since deglaciation, than that which has occurred in eastern Europe. Another outcome of the study, however, has been the successful use of LiDAR imagery to identify additional eskers. With meter scale resolution, LiDAR allowed the identification of four additional eskers that have likely never been mapped. These eskers range in relief from 2-6 meters high and tens to a hundred meters long. Ground-truthing demonstrated that the mapped landforms are indeed eskers. We will present the esker imagery, which reveals that the detailed resolution of LiDAR presents new opportunities for landscape investigations.