RV Heincke cruise HE590 – Spring 2022

In spring 2022, RV Heincke cruise HE590 was led by Achim Kopf and Ralf Bachmayer to carry out shallow dives with the IMGAM AUV in the Baltic Sea. IMGAM is an autonomous platform with a depth rating of 2000m that can detect and sample gas seeps. In that respect, it may be a powerful tool for monitoring CCS sites in the future. We plan to use the AUV in future AIMS3 and GEOSTOR cruises.

RV Meteor Cruise M183 – Summer 2022

In summer 2022, the first large expedition on the Reykjanes segment of the Mid-Atlantic Ridge took place on RV Meteor. Cruise M183 was led by Wolfgang Bach and served mostly to geophysically characterize the area and find suitable locations for later drilling and in situ experiments as part of AIMS3. Besides hydroacoustic surveys to map the bathymetry and get Parasound profiles, we used a sub-bottom profiler on MARUM ROV Squid to identify sediment ponds with thin sedimentary fills on young ocean crust. Heat flow measurements, gravity coring, and deployment of a seafloor lander complemented the survey.

RV Littorina annual test cruise – Fall 2022

In fall 2022, the first of our annual test cruises in Baltic Sea shallow waters took place on RV Littorina. Eric Achterberg coordinated the work and as a main achievement, the newly developed DIC sensor was tested on board for the first time. Results were very promising and defined the path forward in the development, which is jointly done by GEOMAR and Sea & Sun Technology.

RV Merian Reykjanes Ridge – Summer 2023

During a 5-week expedition on RV Merian in the summer of 2023, we returned to the Reykjanes Ridge to use the MARUM MeBo70 seafloor drill in both sediments and basaltic ocean crust. In total, 9 boreholes were completed, four of which were equipped with borehole observatories. Apart from temperature variations, we use osmosamplers to acquire geochemical time series in the upper-crust aquifer system. In the future, these holes may be used for cross-hole experiments, tracer injection, etc. to quantify the flow and physical properties. See the logbook for details.

RV Littorina annual test cruise – Fall 2023

In fall 2023, another RV Littorina cruise in the Baltic Sea allowed us to refine the DIC sensor and also test the newly developed optical pCO2 sensor (joint development of Fraunhofer IPM Freiburg and Sea & Sun Technology) for the first time under marine conditions. All the experiments were promising and it was for the first time that representatives from all 4 partner institutions in AIMS3 were at sea together.