Investigation of Active Fault Movements in the Shanul GAS Basin Based on Micro Geodesic Studies, Fars Province, Iran

The Shanul gas field and its surrounding lands in southern Iran have drawn significant attention due to the presence of abundant gas resources and the numerous earthquakes that shook the region between 2018 and 2020. Over the past three years, more than 900 earthquakes have been recorded, many of them destructive. The most severe event, a Mw 5.7 earthquake, was part of a seismic sequence occurring within an area of approximately 200 km2, causing widespread panic among local residents and nearby villages. Despite the high level of seismic activity, no significant fault had previously been identified on regional geological maps to explain these events. To delineate the boundaries of a possible fault or fault zone based on the aftershock distribution, geodetic and micro-geodetic monitoring methods were employed. The interpretation of the collected data revealed the presence of a latent strike-slip fault with an approximately north–south orientation, which had not been documented in earlier geological surveys. The discovery of this previously unknown fault in an area containing several major gas fields has important implications for the exploration, extraction, and management of hydrocarbon resources.