A significant consequence of an earthquake is the generation of horizontal and vertical displacements on the Earth's surface. These displacements can lead to substantial human and financial losses, varying according to the earthquake's intensity and location. Given Iran's position along the seismically active belt and the presence of the vast Alborz and Zagros mountain ranges, it is crucial to monitor the movements of numerous faults in regions adjacent to these mountains. Over the past two decades, remote sensing techniques utilizing satellite radar imagery have been vital for forecasting and assessing ground movements. In this article, we used InSAR technique and Sentinel-1 radar images to investigate the surface displacement caused by the February 17, 2021 earthquake in Sisakht, Iran. Four images from the Sentinel-1A sensor, captured before and after the earthquake in both ascending and descending modes, were processed in the SNAP software. The results indicate that the maximum displacement in Sisakht is approximately 10 cm along the line of sight (LOS). Decomposing the LOS displacement revealed estimated values of -161 mm for the east-west component and 6 mm for the up-down component.
Considering the extent of the Iran and its location on the main earthquake belt, as well as the presence of many faults with high seismicity in most regions of the country - especially in the areas adjacent to the Zagros and Alborz mountain- the use of classical mapping techniques, due to time-consuming mapping methods and high labor costs, it is almost impossible to measure and monitor deformation. For this purpose, in recent years, remote sensing and radar imaging-based technologies have been widely used to monitor large areas in short periods of time. Among these technologies, the radar interferometry method is combined with the aperture radar, which is called the InSAR method for short. One of the most important effects of an earthquake is the creation of horizontal and vertical displacements on the earth's surface, as a result of which - according to the intensity and the region of the earth-quake- many human and financial losses may occur. Considering Iran's location on the earthquake belt and the presence of two huge mountain ranges, Alborz and Zagros, monitoring the movements of many faults in the areas adjacent to these mountain ranges is very important. The use of remote sensing method based on the use of satellite radar images has played a very important role in predicting and measuring earth movements in the last two decades. In this article, in order to investigate the ground displacement caused by Sisakht earthquake, the technique of radar interferometry (InSAR) has been used. For this purpose, by using the four images obtained from the Sentinel-1A sensor before and after the earthquake in the ascending and descending states of the satellite orbit and processing these images in the SNAP software, the ground displacement map due to the occurrence of this earthquake was created. The results showed that the maximum displacement in Sisakht city is about 10 cm along the line of sight of the satellite. By dividing the displacement obtained along the line of sight into two displacement components in the east-west (x component) and up-down (z component) displacement map was prepared in both x and z directions. These maps provide basic information required for earthquake engineering processes.