Magnetic Signature of Active Hydrothermal Systems in a Volcanic‐Evaporitic Environment in the Danakil Depression

Abstract Hydrothermal systems in volcanic‐evaporitic environments provide unique insights into subsurface geological processes, yet their magnetic signature remains poorly understood. Here we suggest that hydrothermal activity in the Dallol area of Ethiopia produces distinct magnetic patterns that may reflect both physical and chemical modifications of the subsurface. Through high‐resolution near‐surface magnetic surveys, we identify weak positive anomalies associated with reddish brine mud layer and negative amplitude anomalies (∼20 nT) over active hydrothermal features. These patterns suggest that hydrothermalism consistently results in weakening magnetization through mechanical destruction and chemical alteration of substrates, providing insights into fluid circulation and their relationship with tectonic processes. Our findings support that near‐surface magnetic surveys can effectively map active hydrothermal systems across diverse geological settings from volcanic‐evaporitic environments to mid‐ocean ridges with important implications for understanding geothermal exploration, and the evolution of divergent plate boundaries.