Lineament Extraction In Olkaria Geothermal Field Using Sentinel-1A imagery (Kenya).

Abstract

Subsurface processes are displayed as observable ground deformations. Their identification and monitoring provide insight about Earth’s dynamics and processes triggering these conditions. This paper aims to show the application of remote sensing technique in obtaining preliminary information about the subsurface through extraction of geological lineaments in the middle fault zone of the Olkaria geothermal field. The Olkaria West Field (OWF) and East fields are separated by a low-temperature zone; waters from the west field fracture have lower enthalpy. Further, the wells on either side show different reservoir fluid characteristics. In this study, Sentinel-1 Synthetic Aperture Radar (SAR) imagery was used. Image analysis techniques used were Gray Level Co-occurrence Matrix (GLCM) for texture analysis and Line module algorithms for edge detection to obtain the tectonic lineaments. The rose diagrams were used to display the lineaments' orientation. The main trends observed in the lineament map for the zone between East and West fields could be recognized as showing a major trend in S-N, this orientation might be correlated with the fractured volcanic system of Olkaria Geothermal field. Detection of geologic lineaments using free Sentiel-1 data presents a great advantage for future geological surveys.