We have now been mapping continuously since 25 July, when IB Oden reached our survey area after leaving Longyearbyen, Svalbard, the 24th. As we approach the final day of the expedition, we can confidently say that it has exceeded our expectations. Our goal has been to collect high-quality seafloor mapping data along a proposed trans-Arctic cable route, and we have successfully completed the planned surveys.

We first encountered sea ice at about 80°30′N as we headed north along the Yermak Plateau, which extends from the continental shelf of Svalbard. Initially, the ice was relatively easy to break and had little impact on our echosounders, especially the multibeam echosounder and sub-bottom profiler that are central to our mission. Farther north, however, the ice became much denser, and we had to bring out one of our polar "mapping tricks."

The method is affectionately known as the "hokey pokey." Instead of mapping while actively breaking ice, we stop the vessel and let the multibeam echosounder automatically tilt its swath first forward and then backward. This allows us to map both ahead of and behind the ship under calm conditions, avoiding the noise generated during icebreaking. The technique has worked exceptionally well, particularly in the deep waters of around 4,000 metres north of the Yermak Plateau.

We have successfully mapped all the priority areas planned for this expedition with high-quality data, and along the way we have made several exciting discoveries. One of the highlights is a group of remarkably beautiful small volcanic cones in the deep axial valley of the Gakkel Ridge. One of these is prominent enough that we plan to propose a name for it to the international Sub-Committee on Undersea Feature Names (SCUFN).

Another exciting finding is a series of ridges rising on the seafloor and extending in a distinct pattern across the route between the Yermak Plateau and the Gakkel Ridge. One of these rises more than 1,600 metres above the surrounding seafloor, making it large enough to qualify as a seamount, which has to rise 1,000 metres or more. We also intend to submit a name proposal for this feature to SCUFN.

Overall, the expedition has been a great success. Since leaving Longyearbyen, the Stockholm University mapping team has operated the echosounders around the clock in 24-hour shifts. It hasn't all been about watching computer screens, though. We have also enjoyed several memorable encounters with polar bears, whales and experienced the nice scenery of the Arctic pack ice.

Martin Jakobsson
Professor of Marine Geology and Geophysics, Stockholm University