The Cobb hotspot is a volcanic hotspot located off the Oregon/Washington coast of the United States. The hotspot is at the Juan de Fuca Ridge, and has made the Cobb-Eickelberg Seamount chain. The Axial Seamount is the hotspot's most recent eruptive center, which last erupted in 1998.[1]
The central ridge is thicker than the surrounding crust by one to two km and may be accumulated buildup from the hotspot, which is essentially an underwater volcano with a root twenty to forty kilometers in diameter reaching a depth of 11 kilometres (6.8 mi) beneath the volcano. The magma flows at rate of 0.3 to 0.8 m³/s. The caldera is 1,450 metres (4,760 ft) below sea level.[2][3]