Examination of Land Surface Deformation in the Eastern Tennessee Seismic Zone (ETSZ) Using Persistent Scatterers Interferometric Synthetic Aperture Radar (PSInSAR)

Abstract

Aims: The purpose of this study is to detect land surface deformation in the Eastern Tennessee Seismic Zone using persistent scatterers interferometric synthetic aperture radar technique. Study Design: This study employed persistent scatterers interferometric synthetic aperture radar technique to analyze a series of ESA SAR images and derive surface deformation velocity along the slant range direction in Eastern Tennessee Seismic Zone which is the second most active seismic zone in the eastern United States. Place and Duration of Study: Department of Environmental, Earth and Geospatial Sciences, North Carolina Central University, Services between June 2012 and July 2014. Methodology: In this study, forty six ESR ½ SAR (SLC format) images covering two study areas with different seismic activity were inputted to ENVI/SARscape/Persistent Scatterers Stacking Interferometry Module with DEM (10-meter resolution) acquired from USGS. These SAR images cover a part of the ETSZ, with spatial extent between 35.118 and 36.824 degrees north in latitude, and between 83.707 and 84.871 degrees west in longitude and were acquired between 1992 and 1999. After interferometric SAR analysis, ArcGIS 10.2 software was used to conduct spatial statistics of surface deformation velocity along line of sight in both study areas and to examine the land surface deformation in cities located in the west and east of the New York-Alabama lineament. Results: It was found that average uplift/subsidence velocity was higher in the study area which was more seismically active. Results also show that there was no significant difference in average uplift, subsidence and overall velocity between two sides of New York-Alabama lineament in ETSZ. Conclusion: Our findings indicate that there is no direct association between the land surface deformation and the position relative to the NY-AL lineament in the study areas. However, interpretation of results from this study needs to be cautious since there are many factors, in addition to seismotectonic processes, that contribute to land surface deformation. Geodetic measurements such as ground leveling measurements are highly suggested in the ETSZ to verify finding from this study and to identify the deformation sources.