Lombok earthquakes using DInSAR techniques based on Sentinel 1A data (case study: Lombok, West Nusa Tenggara)

Abstract

On July 29th, 2018 there was an earthquake of 6.4 magnitude occurred in Lombok Island, West Nusa Tenggara. The repercussions of the earthquake cause the area to deform. Deformation refers to any changes in the shape and size of an object. Hence the purpose of this research is to measure the deformation cause by the aforementioned earthquake in Lombok. The deformation calculation is conduct by using the SAR data from Sentinel-1A Satellite Imagery (Interferometric Wide Swath (IW)) using DInSAR method. The effect of deformation cause by an earthquake in Lombok based on DInSAR method is -0.001 m up to -0.134 m with the average -0.026 m and the image coherence is 0.32, with the range for coherence is 0 to 1. The small value of coherence cause by the vegetation density within the research area. The vegetation density will affect the imagery coherence value due to its movement and development thus effecting the backscatter. Hence, the deformation data situate within the vegetation density area will result less accurate data.