East Diamante Volcano — United States

The dacitic East Diamante submarine volcano contains an elongated NE-SW-trending caldera with a pronounced rim on the NE side. A large post-caldera cone lies on the SW caldera rim, and a complex of lava domes was constructed in the center of the caldera. Several areas of hydrothermal activity including "black smoker" sulfide chimneys at the Black Forest site were detected on the central dome complex at depths of only a few hundred meters. The summit extends to within 127 m of the ocean surface. West Diamante seamount lies 28 km W, with the much smaller Middle Diamante about 15 km W.