Days 7 & 8: Saturday 27 – Sunday 28 June 2020
Back in Germany, summer time is reaching peak temperatures of at least 30° (even in Kiel!), but here we stay with a chilly 9°C and wind gusts of around 7-8bft. The dream of sunbathing on the deck soon dissolved into nothing when we arrived at 65°N. As waves are getting higher, moving around on the ship is becoming cumbersome and we expect the sea to become even heavier in the next couple of days…thus people may wonder why we are doing this, missing out on beautiful summer time and going in the cold north instead to see only water for five weeks and struggle with sea sickness? I can tell you – it’s so worth it. It is an experience that not many people will ever get the chance to experience: seeing what is there in 3000 m deep in the ocean on the video screen during the ROV dives, touching the seafloor sediment that’s being collected with the MUC or box corer, exploring the sea floor morphology and discovering new structures, bearing witness to the most peculiar deep-sea fauna, hearing the waves smash against the portholes in the cabins … or just sitting in front of the windows trying to spot some whales. And all of this is happening in endless daylight (because the sun doesn’t want to set in these latitudes in this season). It’s an experience nobody will ever forget.
And speaking of seafloor bathymetry, over the last few days we’ve been mapping Aegir Ridge – a former mid-ocean ridge that was active during early Eocene (about 50 million years ago). The associated seafloor spreading processes were one of the main drivers for the formation of the Norwegian Basin. The extinction of Aegir ridge is placed around 25 million years ago in the late Oligocene, meaning that there is no active tectonic movement now, but the typical ridge structures can still be observed in the hydroacoustic data.
Furthermore, unusual seafloor structures hold unusual species and this is what our biology team on board is discovering! What looks like mud-slinging and sludge silt digging is in fact the extraction of the most valuable ground truth data. From very old ancient sediment, conclusions can be drawn about the development of deep-sea life from ancient past right up to the modern day. It is a lot of work though and getting the mud on board is only the very first step: that’s followed by sieving and washing to get rid of the coarser particles, centrifuging to separate organic from inorganic matter, and then manually picking out the interesting bits to look at through the microscope. The ‘rough’ cleaning procedures are already done on the ship but the time intensive precision work is done back home.
Tina Stein (right) is a technical assistant at Senckenberg am Meer in Wilhelmshaven with a focus on biology and genetics. During the cruise she takes care of the plankton net and its catch. When deploying the plankton net, she is the responsible person for the work on deck. It has been her wish to go on a research vessel ever since she started her apprenticeship and now she is here!