M190 Dive@MAR

Distribution of Venting Along the Mid-Atlantic Ridge (29–38°N) and Implications for Hydrothermal Exchange and Vent Ecosystems

Research cruise:

M190 with RV Meteor to the Atlantic Ocean
08.06. – 10.07.2023

Find a Blog (in German) from Prof. Harald Strauß here:  


Participating institutions:

  • UHB                      University of Bremen
  • CUB                       Constructor University, Bremen
  • MPIMM               Max Planck Institute for Marine Microbiology
  • ULy                        University of Lyon
  • UGö                       University of Göttingen
  • UMs                      University of Münster
  • DWD                      Deutscher Wetterdienst, Geschäftsfeld Seeschifffahrt

Project description:

The team for M190 from Prof. Koschinsky’s group. From left to right: Eva-Maria Meckel, Lukas Klose, Annika Moje.

The major aims of cruise M190 with the research vessel Meteor were to coordinate the sampling of their fluids, rocks, and biota, as part of the joint geo-bio interface studies in the Research Area ‘Ocean Floor as a Reactor’ of the MARUM Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface” (https://www.marum.de/Ozeanboden.html). The hydrothermal vents at the Mid-Atlantic Ridge (MAR) between 29°10’N and 37°50’N occur in different geological settings (axial volcano vs. detachment fault vs. axial volcanic ridge) and are therefore geochemically highly diverse. To understand the high diversity of these systems we tried to sample the fluids which are dispersing from the chimney structures for chemistry, the rocks to understand the geology of these systems and bacterial mats and mussels with an ROV (Remotely Operated Vehicle). Apart from sampling hot fluids with the ROV, we sampled the non-buoyant plume which is dispersing from the hydrothermal vent systems and can spread over several kilometres in the water column with a CTD (Conductivity, Temperature, Depth) water sampler. The team from the Constructor University focussed on the dissolved trace metal chemistry from the vent structures, the rising plume and the non-buoyant plume to show how metals transform between different size fractions (0.8 µm and 0.2µm) and what kind of metal-organic complexes along the mixing gradient between vent fluid and ambient seawater. This information is important for estimating the hydrothermal flux of trace metals into the ocean. Our sampling areas were the Broken Spur Hydrothermal Field (BSHF), the Main Lucky Strike Hydrothermal Field (MLSHF), the Rainbow Hydrothermal Field (RHF) and the Menez Gwen Hydrothermal Field (MGHF), where we sampled high temperature and pressure hydrothermal vent fields with over 300°C and diffuse outflows with temperatures between 20°C and 200°C.

Main research questions:

  1. How diverse are the hydrothermal fluids between those km-spaced vents and what are the volcanic and faulting controls of this diversity?
  2. How are metals transformed within the rising and neutrally buoyant parts of hydrothermal plumes and how is the fate of metals controlled by primary differences in metal:sulfide and metal:carbon ratios?
  3. What can we learn from comprehensive analyses of diffuse fluids about subseafloor microbial activity?
Broken Spur 1
Hydrothermal chimneys at the Broken Spur hydrothermal vent field at a depth of 3000 m, also known as black smokers. The black rising smoke are rapidly precipitating iron sulfides (FeS) due to rapid cooling. Source: MARUM − Zentrum für Marine Umweltwissenschaften; Universität Bremen.
Sampling Fluid
Sampling of a diffuse outflow with the KIPS (Kiel Pumping System), which is a Multiport Valve-based all-Teflon Fluid Sampling System for ROVs (Remotely Operated Vehicles). Source: MARUM − Zentrum für Marine Umweltwissenschaften; Universität Bremen.
Chimney structures at the Rainbow hydrothermal vent field. Source: MARUM − Zentrum für Marine Umweltwissenschaften; Universität Bremen.
Broken Spur 2
Vent fauna (anemones, mussels, crabs and shrimps) close to the venting areas of the Broken Spur hydrothermal vent field. Source: MARUM − Zentrum für Marine Umweltwissenschaften; Universität Bremen.