Characterization of a Giant Pockmark Field in the Gulf of Oman: A New Contributor to the Arabian Sea Carbon Flux

Recent discoveries of marine gas seeps and pockmarks along the northeastern Arabian continental margin in the Gulf of Oman indicate a significant carbon flux into the Arabian Sea and atmosphere. However, detailed statistical analyses of these pockmarks and the volumes of gases released into seawater or the atmosphere remain unexplored. This study addresses these gaps using newly acquired high-resolution multibeam bathymetry and wideband echosounding data. Active seeps are detected through wideband echosounding, while semiautomated picking identifies the number, diameters, depths, and trends of existing pockmarks. The volumes of circular pockmarks are calculated, and for pockmarks eroded by bottom currents (e.g., crescent-shaped and elongated ones), initial volumes are estimated based on the smallest circular pockmarks, representing the most recent formations. The total volume of all pockmarks provides an estimate of the gases released into the sea, thereby assessing the contribution of this pockmark field to the global carbon reservoir and present/paleo-climate changes.