Greetings from onboard the R/V Helmer Hanssen, where we are exploring the Barents Sea in the region south of Svalbard. The quest for mapping territory has driven explorers and scientists for centuries, and for us on this cruise it is no different. Our domain of exploration extends south and southeast of Svalbard, in the regions called Spitsbergenbanken, Hopendjupet, Nordflaket, and Bjørnøyrenna. The objectives of this 18-day expedition, “CAGE-22-6-HH”, are manifold but the main aim is to map and study sites of fluid flow on the seafloor, which can be related to natural methane and gas seeps, and link to their geological setting.
Sunday 14th August 2022
Text: Grace Shepard
Figure 1: Overview of the bathymetry of the Barents Sea and cruise-track thus far. We departed Longyearbyen on August 2nd 2022 and expect to arrive in Tromsø on August 20th.
It is also an educational cruise, both as a UiT and UiO field course (GEO-x144) and a UNESCO Teaching-Through-Research course (TTR-22). There is therefore a heavy hands-on and two-way educational component between the students and senior scientists onboard.
We are a scientific party of 13 people, plus two instrument engineers, and the ship’s crew. We are 10 nationalities – Australia, Brazil, Britain, Columbia, Denmark, Italy, Germany, Norway, Russia – and from four universities (UiT, UiO, Bologna and Kiel). Onboard, there are experts on seismology, glaciology, marine geology and geophysics, oil and gas processes, paleontology, mud volcanos, oceanography, plate tectonics, numerical modelling, seismic hazards, gas hydrates, methane emissions, and more, so there is plenty of science to be exchanged.
Figure 2: PhD candidate Juan Camilo Meza Cala in the instrument room looking for gas flares. The bottom triangular window on his screen even shows a flare (yellow feature in the middle dipping to the bottom right).
Three of us onboard are from a “sister” Centre of Excellence in Norway – The Centre for Earth Evolution of Dynamics (CEED) at the University of Oslo – which was established in the same funding round as CAGE (2013-2023). Our centres have already collaborated a few times before for expeditions, research and education, and it is a pleasure to combine forces once more whilst both centres still exist!
On a regular work day, I study the past configuration of landmasses and oceans – also known as plate tectonics. I have a particular interest in the formation of the Arctic and North Atlantic, as well and the processes occurring in the deep interior of the Earth (down to 2900 km below our feet). To do this, I typically look at timescales of tens or hundreds of millions of years in the past, so a switch to more “recent” glacial and Holocene sedimentation timescales is a welcome change. I just have to drop a few zeros from the 100,000,000 years, and we’re in business!
Figure 3: Some of the newly mapped features on the seafloor. Including a) annual sedimentary deposits from past glacial channels, b) “hill-hole” pairs possibly formed when sediment blocks freeze onto the base of the ice sheet before being dumped downstream, and c) some of the many iceberg scours that wiggle in all directions. These images are made from the multibeam data as the ship passes overhead and are loaded into the software, Fledermaus.
It follows that when I think of “seafloor” processes, I usually strip away the topmost sedimentary cover to look at the rock layers below, but on this particular cruise I have discovered for myself an exciting world of features on the very top of the bottom.
The ship’s multi-beam instrument maps out the depth to the seafloor (bathymetry), which in turn reveals many bumps and holes of different sizes and shapes. Many of the (presumably) glacial features are probably very familiar to the long-term readership of this blog, but they are quite new to me. It is quite fun to see them being mapped out for the first time at this resolution, and in real-time too. It is also a reminder about the constant state of change occurring across our planet at all sorts of time-scales, no matter the number of zeros!
Figure 4: A zoomed-in and 3-D perspective (vertical exaggeration) of the multi-beam seafloor data as shown in plot c of Figure 3. A profile running across the path reveals some of the highs and lows.