Definition(s)
Mud Volcanoes
Diapiric intrusion of plastic clay causing high pressure gas-water seepages which carry mud, fragments of rock (and occasionally oil) to the surface.
NOTE The surface expression of a mud volcano is a cone of mud with continuous or intermittent gas escaping through the mud.
Source:API RP 2EQ, Seismic Design Procedures and Criteria for Offshore Structures, First Edition, November 2014. Global Standards