Induced seismicity effect in Morocco caused by the reduced volume of underwater according to stacking-insar and gravimetric data

Using Sentinel-1 satellite radio interferometry data, the geodynamics in the area of the epicenter of the destructive Mw = 6.8 earthquake that occurred in Morocco on September 8, 2023, were studied using the Stacking-InSAR method applied to 801 interferograms. Over the period from January 2019 to September 2023, local surface subsidence with an average speed of 1.5 cm/year was discovered, and the maximum speed was identified in 2023 and amounted to 24 cm/year, for areas with a developed melioration system located above aquifers. Based on an integrated analysis of changes in the water equivalent thickness, measured from satellite gravimetric data for 2000–2023, and the amount of precipitation, it was found that the surface subsidence was due to a huge irrigation draft. Assuming the similarity of shapes of isoseists of earthquakes with close epicenters, a comparison of the isoseists of earthquakes that occurred in 2014 and 2023 was carried out, which made it possible to identify the expansion of the contours of the isoseists towards the descending surface areas for the earthquake from 2023. This process, along with the tectonic movements of the Eurasian and Nubian plates, is believed to increase the stress-strain state between two aquifers, what caused the Mw = 6.8 earthquake in Morocco on September 8, 2023.