A core that stretches forever - CAGE, Centre for Arctic Gas Hydrate, Environment and Climate

Centre for Arctic Gas Hydrate,
Environment and Climate

A calypso corer can penetrate up to 30 meters into the ocean floor and fetch sediment cores the length of a blue whale. When on deck the core seems to stretch forever. Photo: Carmen Braun

Text and photos: Carmen Braun

This is my first cruise with a Calypso corer, so I am very excited about it! As previous posts have explained, we have a multi-corer and a gravity corer as well, but neither can penetrate nearly as deep as the Calypso. When it is on deck, it seems to stretch forever.

ship, ocean, freezing, ice, cold, arctic, KPH, — It takes some time to get the corer from its resting place to over the side of the ship and rotated so it is vertical. The technicians fix it up so that the weight (the yellow and orange) is properly secured to the trigger. You can also see how the rough seas of a few days ago left their icy mark on the side of the ship. Photo: Carmen Braun

Here, you can better see the trigger set-up. Eventually, the long yellow arm will have a weight attached to it via a cable that is a little longer than the coring tube. When this weight hits the seafloor, the arm lifts up, releasing a catch attaching that part of the set-up to the weight by a cable, you can see the length of cable coiled nicely. This allows the corer to plunge deep into the sediment, propelled by the huge weight.

Getting the tube back on board is exciting, but painstaking process.

The process of rotating the coring tube back to horizontal and bringing it onboard the ship is slow and careful. The metal ring around the coring tube helps to support it during this process.

person, cleaning, deck, ship, red, blue, arctic, ocean, sky — Once it is onboard, it is important to clean the outside of the coring tube, partially because it’s just better to keep all equipment clean, but the nature of the Arctic environment means the sediments stuck to the outside would quickly freeze solid if not pressure-washed away quickly!

Getting the sediments out: To get the sediments out of the giant tube, we use this contraption to push them out. It is a slow process: turning the crank pulls a cable attached to a long stretch of pipe, which pushes the core liner out. However, because the core is so long, it is necessary to stop and add new pipe segments quite frequently! On the other end of the core there is a team working furiously to cut the core into more manageable metre-long segments as it is pushed out of the tube.

Of course, it is also very important to stop and enjoy the amazing views! I personally thought the sunset reflected in the freshly washed core, with sea ice drifting by, was especially picturesque, and since we will soon enter into polar night, it was all the more important to appreciate the moment.

30. October 2019

Pore water and cinnamon rolls

28. October 2019

Chief Scientist’s Diary: Jochen Knies