Weekly Reports

On this very same Sunday, Oct 11^th, something that seemed unthinkable just few months ago, suddenly became real: We are on board RV Meteor on our way to the southern Iberian Peninsula where we are planning to investigate the nature of the contact between the Eurasian and the African plates in this region and test cutting edge underwater technology in the frame of the EU Marine Robots H2020 project. Among the key goals of the cruise are the recovery of several long-term instruments that were deployed on the active faults and mud volcanoes in both the Alboran Sea (Mediterranean) and Gulf of Cadiz (Atlantic) during previous Meteor expedition M149 by using the ROV SQUID from MARUM.

The scientific crew is composed of 15 between Postdocs, Technicians, undergrads and postgrads students from MARUM, IPMA, MPI, GEOMAR and the University of Rabat, representing an astonishing number of 8 nationalities. The current expedition (GPF 18-2_040) should have initially started in July but due to the ongoing COVID pandemic has been rescheduled as the current M167.

On Saturday the 10^th we were allowed to embark the RV Meteor after four days of quarantine in a Bremerhaven Hotel, and being tested negative for COVID-19. A bus transfer from the hotel to the ship, berthed in Emden, delivered us safely to the vessel which we will call home for the next 4 weeks. We left port this morning, Oct 11^th, passing through the sluice gate that connects the Harbor of Emden with the Wadden Sea, after both the ROV SQUID and all the scientific equipment was safely unpacked and prepared for transit.

We send the best wishes from the tidal flats of the North Sea and take this opportunity to especially thank the German Science Foundation, the German Research Fleet Coordination Centre (and namely Andrea Gerriets and Karsten Heikens), the shipping company Briese Research and the crew of the R/V METEOR with captain Rainer Hammacher for the tremendous support they have provided in preparing the cruise.

On behalf of the entireM167 Team
Walter Menapace (Chief Scientist)

For most part of the second week onboard RV Meteor we steamed towards the easternmost of our two study areas, the Alboran Sea. The transit, which started with a somewhat rough crossing of the English Channel, ended on the 17^th night with a quiet entrance in the Mediterranean Sea.

During the whole week the scientists, which are mostly new to the ship, had the chance to get acquainted with the life on board and had to participate to the mandatory safety drill simulating an abandon ship situation. Science also kept the M167 participants busy, laboratories were prepared for the first “core on deck”, science meetings were held daily in the conference room, and the first multibeam profiles were taken during transit, in order to contribute to the DAM Underway Bathymetry project.

On Sunday the 18^th we were finally on our first station and, due to a calm sea state, we were able to dive with the ROV SQUID from MARUM, in order to retrieve the CORK observatory we deployed on the seafloor during the M149 expedition (2018). Unfortunately, the first dive failed due to an hydraulic problem and on the second deployment we could not find the CORK in the dive area. We will try again during the next week, being able to cover more seafloor surface with multiple dives. After the ROV SQUID dive we were also able to successfully deploy a small COTS-ROV from MARUM. This so called “BlueROV” underwent a number of modifications compared to the original product with respect to manipulation, control, etc. More exercises are planned in the coming days to establish more versatile and affordable ROV-work in the near future.

The scientific program just started and all the M167 participants are looking forward to give their contribution to the expedition. Everyone on board is feeling well and is enjoying the warm temperature and nice weather. More science will come in the next weeks, we are just warming the (ROVs) motors!

On behalf of the entire M167 Team
Walter Menapace (Chief Scientist)

The week started in the Alboran Sea, the first of our two study areas. During the night we could extensively map the Carboneras fault, being able to produce a series of interesting Parasound profiles through it. Taking advantage of the beautiful weather and the perfect sea conditions on Monday the 19^th we deployed the ROV SQUID in order to retrieve the first CORK, a long-term observatory installed on the seafloor by MeBo in 2018. The dive was extremely successful, the instrument was safely retrieved, and we could then steam away in the direction of the Gulf of Cadiz.

We reached the Gulf of Cadiz on the morning of the 20^th and, due to the prohibitive weather condition for a safe SQUID deployment, we finally had the hance to get out first sediments cores from the seafloor. We managed to retrieve different mud breccia facies, a typical sediment constituting the main solid emissions of mud volcanoes, from different structures of the Moroccan mud volcanic field: Ginsburg, Yuma, Boabdil, and Averroes. These sample will be studied in order to determine the geochemical composition of the porewater, as well as the presence of microbial activity, in an effort to shed some light on the origin of the fluids and the life which they could fuel.

On the 21^st and part of the 22^nd we continued coring different structures which then proved to be newly discovered mud volcanoes, in the northern part of the Moroccan mud volcanic field. In the afternoon of the 22^nd the wave height <2m made possible an ROV deployment, which again concluded with a flawless retrieval of the second CORK observatory, installed on the active Ginsburg mud volcano. On Friday, Saturday and Sunday (23^rd, 24^th and 25^th), due to excellent weather, we were able to dive again on Ginsburg MV, on the Lineament Center and on a coral mound structure, respectively, in order to produce a 3D Photomosaiking reconstruction of the seafloor on these extremely interesting targets. Meanwhile, we also continued coring and surveying various morphological features, which proved to be unknown mud volcanoes, circular depressions, diapiric ridges and coral mounds.

Everyone on board is contributing to the success of this expedition and, as the days go by, the scientific team gets more united, making the work on board very pleasant.

On behalf of the entire M167 Team
Walter Menapace (Chief Scientist)

At the beginning of this week we decided to steam towards the western part of the Gulf of Cadiz, in order to sample some deep-water mud volcanoes (MVs) and a new MV field. The deeper MVs are interesting because they are following the traces of both Lineament South and Center. They can potentially show different source fluids/sediments than the bigger expulsion features on the eastern part of the accretionary prism, thus painting a more complete picture of the Gulf of Cadiz mud volcanism.

We reached the new MVs field in the Portuguese EEZ on the morning of the 27^th, after a night spent by thoroughly mapping the area. Some structures in this area were discovered during the M149 in 2018, but no complete map was done until now. We managed to sample and confirm two of the MVs, but then the winch used for gravity coring broke down and it took a team of 4 ship mechanics 8 hours to repair it, making coring operations unfeasible for the rest of the day. Talking advantage of a window of good weather, on the 28^th we headed to the Lineament Center, at the location of the CORK observatory. Despite an hydraulic malfunction which impeded the use of the ROV mechanical arm, the ROV team managed to build an extension for the same arm, making the retrieval of the CORK possible. After this unexpected but welcomed success, we closed our scientific program by coring different structures along the northern boundary of the Southern Lobe. Again, we discovered a new MV and sampled the known Atlas, Student and Jesus Baraza MVs which showed an amazing variety of mud breccias, confirming once again the extreme variability of these seafloor features in the Gulf of Cadiz. Finally, on the 29^th afternoon we started our transit towards Emden.

The M167 expedition is now coming to an end, with the RV Meteor entering tomorrow the English Channel after passing unscathed through the Gulf of Biscay earlier today. The scientists onboard are still busy with packing, writing down results, and enjoying the last days onboard, before disembarking on the 05^th November in Emden. In conclusion, I would like to express my appreciation to the work of both scientists and crew, which allowed a smooth and successful completion of this research expedition.

On behalf of the entire M167 Team
Walter Menapace (Chief Scientist)