Evidence of submarine groundwater discharge (SGD) along the northern Persian Gulf: Insights from physicochemical profiles and structural geology

Submarine groundwater discharge (SGD) plays a significant role in the hydrological and environmental balance of arid coastal systems like the Persian Gulf. This study investigates the presence of SGD signals along the northern coastline of the Persian Gulf using seawater physicochemical data from the ۱۹۹۲ Mt. Mitchell oceanographic survey—prior to major anthropogenic impacts such as desalination activities. A total of ۷۴ vertical seawater profiles were analyzed, each containing high-resolution measurements of salinity (۳۶.۵۹–۴۳.۹۳ psu), temperature, and dissolved oxygen (۱.۳۱–۵.۸۵ ppm) from the surface to seabed. The results reveal unusual stratification patterns—such as freshening near the seabed and increased oxygen levels—particularly near the Kazerun-Qatar (KQF), Hendijan-Bahregansar (HBF), and Karehbas (KMF) fault zones. These anomalies strongly suggest offshore freshwater inflow, likely controlled by deep fault systems extending from the Zagros Mountains. By using historical, pre-desalination datasets, this study minimizes confounding from modern effluents and introduces a novel, regional-scale approach for detecting SGD in the Persian Gulf. The findings highlight the possible influence of deep-seated fault zones in offshore SGD, especially in the western basin. These insights offer a novel approach to water resource assessment and SGD monitoring across the Zagros domain.

کلیدواژه ها:

submarine groundwater discharge ، SGD ، fault zone ، ROPME ، Persian Gulf