Mud volcanoes revealed and sampled on the Western Moroccan continental margin

We surveyed and sampled two active and 3 inactive mud volcanoes on the Atla ntic continental margin of Morocco. The active mud volcanoes (named Yuma an d Ginsburg) are each about 4 km in diameter, rise between 150-250 meters ab ove the seafloor and are the first active methane-related mud volcanoes to be identified in this region. The inactive volcanoes range in diameter from 1 - 3 km, with relief between 50 and 80 meters. Gravity cores from the cre st of the active mud volcanoes yielded methane hydrates and mud breccia dep osits. Chemosynthetic communities of Pogonophora worms and the bivalve Sole mya were found on the surface of the active mud volcanoes. Sediment cores f rom the inactive volcanoes contained hemipelagic sediments, rich in foramin ifera and ahermatypic coral debris, overlying mud breccia.