Meteor Blog 5. August: Dancing on the mud volcano

Planetearth Blog

Does the biodiversity of deep-sea organisms play a role for the climate on Planet Earth? Questions all about marine research will be answered directly aboard of the German research vessel Meteor by cruise leader Prof. Antje Boetius and her crew. In cooperation with the geoportal planeterde.de from 17.08.08 to 24.08.08 they contribute a Science-Blog of METEOR expedition M76/3 GUINECO – MARUM research of fluid and gas seeps on the Westafrican continental margin. Technical highlight of the cruise is the remote-controlled under water robot QUEST4000 by MARUM that will be deployed for taking fauna and sediments samples and conduction of in situ experiments. Go on a dive down to places no other human being has ever seen before: explore the fascinating deep-sea fauna and watch the scientists’ work at gas and fluid seeps deep down on the ocean bottom.

Expedition M76/3b is a collaboration of MARUM – Center for Marine Environmental Sciences at Bremen University and its associated institutes MPI and AWI as well as the French research institute IFREMER and the University of Paris.

More Informationen of the Meteor-Blog, an overview of all contributions to the blog and expedition M76/3B:

5. August 2008 (Author: Jörn Tonnius)

Present Position

Today’s blog is again contributed by Jörn Tonnius, PhD Student in the Geochemistry Group of the MARUM Bremen. Check out BLOG 18.07.08 for more info about Jörn.

Dancing on the mud volcano

This morning the Meteor set course for a new research area. The mud volcanoes, which Cesar Capacharin had found during one of his long night shifts in the sonar room (link to blog entry 2.8.08) are situated only approximately four hours (41 nautical miles) from our main research area REGAB. This distance was ideal for a day of exploration of the mud volcanoes via multibeam and TV-multicorer. Also, this detour offered a good chance for the ROV crew to complete repair and maintenance and added time for the in situ equipment that we had left on the seafloor at REGAB to finish its measurements.

picture 1. Map of the mud volcanoes of the Congo margin (by Cesar Caparachin)

After some hours of fresh sea breeze, we reached the mud volcano area (picture 1). Here, the water depth is only about 2000 meters deep, but the influence of the nearby river mouth of the Congo still gives the sea surface a very dark blue to black color.
 At first, the ship followed several loops above the area to acquire better multibeam data for the planning of the TV-Multicorer transects. In the afternoon, the big, spiderlike instrument was lowered into the deep (picture 2: The multicorer is deployed). It is connected to the ship via a cable to enable a remote visual monitoring of its journey three meters above the seafloor. More and more people crowded into the small control room that was illuminated only by the faint glow of the monitors.

Wide, empty mud plains passed below the multicorer, intersected only by small chunks of carbonate. Suddenly, a huge carbonate chimney of several meters height loomed out of the dark. Only the quick reaction of the winch driver avoided a potentially fatal collision with the coral encrusted rock. Apart from these remains of former activity, the mud volcano seemed quiescent. Further indications for this finding were the secondary coral and echinoderm fauna inhabiting the carbonates, the absence of mussel beds and bacterial mats, and the very homogeneous sediments without any trace of elevated methane concentrations.

picture 3: Andre is cleaning up after hard work on mud volcano sediments

The investigation of the second mud volcano did not reveal any additional structures despite thorough analysis of sediments (picture 3). The tight expedition schedule will most likely not leave any time for further investigations. Nevertheless, the discovery of these structures, formerly unknown for this region of the Congo margin already is a small sensation and will most likely prompt further research in the future.

picture 4: A mussel-and-tubeworm-impersonation of our chief steward Jan

While waiting for the last sediment samples, the scientific team used the occasion to celebrate the birthday of one of the crew members and to prepare an adequate present (picture 4).

Dear regards to everyone at home and abroad,

Jörn