_:b1218678 "GEMINA:ag"^^ . _:b1218678 . _:b1218678 "Wikipedia:Pockmark"^^ . _:b1218678 "A pockmark field is an undersea feature formed by shallow seabed depressions, typically several tens of metres across and a few metres deep. Generally, they are formed in soft, fine-grained seabed sediments by the escape of fluids (gas or water, but mainly methane) into the water column."^^ . _:b1218678 . _:b1218678 .