Land Subsidence Monitoring in Cepu Block Area Using PS-Insar Technique

Abstract

Land subsidence can be caused by many factors, from natural through anthropogenic processes. Land subsidence due to anthropogenic factors results from such as fluid withdrawal, like oil and gas extraction. Cepu block is one of the oil and gas extraction areas that become Indonesia’s largest oil producer. This paper employs the Permanent Scatterers Interferometry Synthetic Aperture Radar (PS-InSAR) with C-Band Sentinel-1A imagery data to monitor the land subsidence phenomena. The PS-InSAR method is chosen because it can measure small movements in an area over time with millimeters DEM accuracy. The processing result showed deformation in the form of land subsidence in almost all of the blocks, except for Block D, with the mean velocity ranging from -27,75 to -9,78 mm/yr. An uplift phenomenon is also achieved in the eastern part of Block E. These PS-InSAR results are in the form of Line Of Sight (LOS). This paper correlates the land subsidence with geological maps to better understand the phenomena’ causes.