Deep-subaqueous implosive volcanism at West Mata seamount, Tonga

Deep subaqueous volcanic eruptions (>500 m below sea level (mbsl)) remain enigmatic due to a lack of visual observations and difficulty recreating ambient conditions in the lab. Eruptive activity at West Mata seamount May 2009 remains one two deep have ever been filmed. A distinct low-intensity eruptive style, termed bubble escape activity, was observed Hades vent (1200 mbsl) characterized by ascent implosion 0.2 - 1 diameter volatile-filled vapor bubbles (Resing et al., 2011). Video this is used constrain simple numerical models produce first eruption actualistic model driven observations. Bubble occurs three stages defined changing exsolved volatile lava behavior. During Stage 1, magma filled conduit drives either ductile or brittle deformation surface vent, depending on timescale cooling prior activity. Fragmentation during 2 culminates with coming into direct contact water. At point, 3, implode through rapid condensation contraction phase, heat loss from Numerical modeling expansion vents across ocean depth range has identified transition characteristics 5 MPa. This would fundamental change processes, which shallow end members are defined. highlights implosive behavior underpressure that develops as key, but often overlooked, component both pyroclastic effusive volcanism entire range. stands contrast overpressure driving subaerial explosive eruptions. The fact volatiles can expand, contract, maintain an approximately constant volume also calls for careful application terminology (e.g. explosive) describe processes.