ASSESSING THE PREVALENCE OF SEISMICALLY-TRIGGERED MASS WASTING IN THE SOUTHERN APPALACHIAN MOUNTAINS, ALABAMA, USA

Recent geologic mapping in northeastern Alabama by the Geological Survey of Alabama has identified large rock block slides located downslope of areas where the ridge is parallel to the orientation of regional fractures. Given the proximity of the eastern Tennessee seismic zone, these landslides may record ancient earthquake activity. We present 3,500 joint orientations and structural data collected along the length of the eastern Tennessee seismic zone that were measured along strike from Giles County, Virginia to Birmingham, Alabama. The discordance between joint orientations and local strike of ridges is used to (a) identify high- and low-risk rock block slide zones and (b) focus searches for unmapped, ancient landslides in both the field and using high resolution digital elevation models, including Shuttle Radar Topography Mission (SRTM) and light detection and ranging (LiDAR) based data. Potential landslides zones are further compared to known seismically active areas and basement faults within the eastern Tennessee seismic zone.