The M112 campaign of the German research vessel Meteor, in which OGS is involved, has observed gas emissions from seabed mud volcanoes in Italian waters. The gas bubbles are rising into the ocean from a structure known as Venere Mud Volcanoes, a pair of extrusive cones up to 100 m high that lie in 1500 m water depth in the Ionian Sea, some 30 km south of the Calabrian coast.
Mud volcanoes were first identified in the eastern Mediterranean Sea over 35 years ago, but it is only in the last 15 years that systematic seabed mapping using multibeam acoustic systems has revealed the true extent of the phenomena. The mud volcanoes south of Calabria were first identified in 2005 during a campaign of the OGS Explora for the EC project HERMES, and have subsequently been the objects of several European research campaigns.
The aim of the M112 campaign, led by Prof. Gerhard Bohrmann of MARUM (University of Bremen), is to investigate active mud volcanoes, which are characterized by recent mud flows and by emissions of fluids and gases. Of particular interest is the presence of methane hydrates, ice-like compounds of water and gas that form within seabed sediments under certain conditions of temperature and pressure, and provide a concentrated reservoir of methane that is used by chemosynthetic organisms living at and below the seabed.
Since leaving Catania on 6 November, the M112 campaign has surveyed over 30 mud volcanoes, using hull-mounted acoustic systems to detect anomalies in the water column due to streams of gas bubbles. The gas bubbles observed at Venere mud volcanoes are now being investigated in detail using a range of techniques: a microbathymetric survey using the MARUM SEAL, an AUV (Autonomous Underwater Vehicle) that flies 80 m above the seabed; seabed observations using the MARUM Quest, an ROV (Remotely Operated Vehicle) equipped with video cameras, robotic arms and sampling equipment; and the acquisition from the ship of sediment cores and water column samples.
The location of the R/V Meteor can be found here: http://www.sailwx.info/shiptrack/shipposition.phtml?call=DBBH
More information on the campaign (in German) can be found here: www.marum.de/Binaries/Binary28892/M112-W31-English.pdf and www.nationalgeographic.de/meteor