Significance of biogeochemical processes in mud volcanoes

Abstract

Mud volcanoes are formed by the upward intrusion of deformable, low-density material as mud diapirs. Most mud volcanoes are located near continental margins. Recent studies have revealed the biogeochemical and microbiological characteristics of the deep sediment found in mud volcanoes.

In the submarine mud volcanoes off Tanegashima island, sediment-inhabiting Atribacteria have been found in methane plumes in the overlying water column. This observation suggests that microbes are dispersed from the deep sedimentary biosphere to the overlying hydrosphere through submarine mud-volcanic activity. Scientific drilling conducted at the submarine mud volcano in the Kumano basin has revealed that the production and migration of fluids in an oceanic subduction zone is closely related to the production of natural gas by microorganisms living in deep sediments at mud volcanoes.