Journal de télédétection et SIG

Abstrait

Determination of Crustal Deformation around Afar (Erta Ale) using Sentinel 1 SAR Interferometry

Andnet N, Daniele Perissin and Tulu Besha

This study is conducted to analyze the crustal deformation pattern at a locality in the Afar region which is geographically located in northern part of east African rift valley between 13° 20‘N to 13° 50‘N latitudes and 40°30‘E to 41°00‘E longitudes, within the triple junction that is formed by the Arabian, Nubian and Somalian diverging plates. The region is one of the active volcanic areas in the world, where the episode of plate movement resulted in seafloor spreading that causes the earth’s surface to deform in the form of surface cracking, sliding, subsiding and faulting. Presently this dynamic process of earth’s deformation in space and time can be accurately detected by satellite space geodetic observations. Using SARPROZ software we applied PSInSAR technique to estimate crustal deformation in the study area based on the analysis of geodetic data. Sentinel-1A SAR image datasets from October 2014 to December 2019 were used to make multi- temporal analysis and we obtained the corresponding subsidence map over the Afar area (Erta Ale). The land deformation analysis showed that the investigation is suffering a severe land movement in most of the area of interest (AOI) which varies approximately from −29.61mm/year (subsidence) to 4.31 mm/year (uplift), and the cumulative displacement from -153.32mm to 24.29mm respectively. The highest value was observed around Erta Ale. This indicates that magma flow and volcano-tectonic activities are still a primary mechanism of deformation.