Finding a needle in a haystack

03 October – 82° 53’N

13:37 on board Kronprins Haakon over the Gakkel Ridge. Today, the ice drift is collaborating with us and with some calculations and good planning from the bridge, we deploy OFOBS (Ocean Floor Observation Bathymetry System) for video and bathymetry transects over the Aurora vent field. Our vent hunting is guided by the vent position provided by Antje Boetius (AWI), obtained during her discovery cruise on-board the Polarstern in 2014. Flying over the vent with OFOBS might sound easy, but there are some obstacles that we have to overcome first….

1. We are at the mercy of the ice drift.
2. We are working with a towed vehicle with a fixed camera that cannot be piloted to look around.
3. Our field of view is that of the OFOBS camera, which is limited to 5 m².
4. We are working on rough terrain of mounds, throughs and steep hills targeting black smokers with hydrothermal fluid flowing at approximately 350 °C on top of a hydrothermal mound that is approximately 10 m tall.
5. The seafloor is 4 km below the vessel.

OFOBS (AWI) being deployed from RV Kronprins Haakon.

But today we get lucky: we are at the edge of a large lead with open water and thin ice surrounding the ice floe currently covering the Aurora vent field. The drift will take us over the vent site, so by hanging on the edge of the ice (instead of getting stuck in the ice with no maneuverability) there is a possibility of slowly moving the 100 m and 10 thousand tonnes  of the RV Kronprins Haakon to try to get the camera of OFOBS to capture the Aurora black smokers.

A black smoker at the Aurora vent field. Photo: OFOBS team, AWI.

As we approach the vents, the scientists gather across multiple screens – the tiny winch room, where OFOBS is controlled from, proves to be a hotspot with 16 people stuffed in 4m², while the conference room has more people annotating what we see on the seafloor. The enthusiasm is touchable, and when the first vent makes its first appearance, we explode in cheers and hugs. With a tiny field of view, it is evident that we located a needle in a haystack. In fact, the drift carried us right through the black smokers with OFOBS being quite the champion by capturing the plume with its camera lens. For many of us, it is the first time we have the opportunity to see such exotic and dynamic systems “face to face”, in their full glory, pouring huge quantities of black smoke out from the depths. In total we managed to capture the beautiful vent fields on camera over several occasions and many scientists reported back goosebumps. All in all, this was a day full of success stories, a lot of luck and one that most of us will never forget.

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