(Text: Ingrid Wiedmann)

In van Mijenfjorden, we also deployed a sediment trap array, which consists of a surface buoyancy, a long rope and an anchor at the bottom.

Schematic drawing of the sediment trap array (graphic by Ingrid Wiedmann)
Schematic drawing of the sediment trap array (graphic by Ingrid Wiedmann)

At different depths (20-40 m) the sediment trap cylinders are placed and they collect the sinking material during the deployment time of approx. 18-24 h.

While the sediment traps were deployed in van Mijenfjorden, a major ice floe loosened from the land fast ice and drifted towards the trap array. We are afraid that we could loose the equipment, when the ice floe would tear the rope apart. Another potential scenario would have been that the ice floe would have covered the surface buoy, and thus the equipment would have been out of sight for us and could be lost.

John, the skipper of R/V Helmer Hanssen, thus got a very special task on his birthday: He turned Helmer Hanssen into an ice breaker and went back and forth to crush the ice. In this way, the ice mainly drifted around the anchored sediment trap and we could recover it nicely after 18 h of deployment.

Sediment trap array threatened by the ice floe (picture by Ingrid Wiedmann)
Sediment trap array threatened by the ice floe (picture by Ingrid Wiedmann)