Dr. Mary-Louise Timmermans
August 2, 2011
Our cruise track brought us nearby another Ice-Tethered Profiler (ITP 33) that was reporting GPS positions but had stopped sending water-column data in late January. Recovering the ITP would not only provide us with valuable hardware, it would also allow us to diagnose the problem, and possibly even recover data that had not been transmitted via satellite. Before it stopped reporting profiles, the system had sent back perfect data from the Beaufort Gyre for 16 months.
Helicopter Pilot Christopher Swannell flew Rick Krishfield and John Kemp (WHOI) on reconnaissance to visually locate the ITP based on updated coordinates that Jeff O'Brien back at WHOI was able to provide to Rick via Iridium satellite phone. The ITP was 20 miles north of the ship. (We've lost our internet connection now since we're too far north of the geostationary orbit of the satellite.) After spotting the ITP, Chris landed and John and Rick fastened a tether around the base of the buoy, so it could be hooked and recovered from the ship. After returning to the ship the helicopter party consulted with the Captain so he could decide the best approach for a recovery from the Louis.
Once we were on site, the Captain maneuvered the ship to break the floe holding the ITP, and a quick recovery ensued. After almost all the wire rope was winched aboard, the line over the side went slack and it became clear that the profiling unit was no longer attached. The most likely scenario is that the profiler and bottom weights were sheared off when the ITP system drifted into shallower waters over the Northwind Ridge at the western boundary of the deep Canada Basin. Although this second ITP recovery attempt was not as rewarding as the first, the ITP 33 surface unit was in good condition and the parts can be re-furbished and reused for another deployment. In fact, the yellow surface float appeared brand new except for a little red bottom paint from the Louis!
We wrapped up the day with a CTD/Rosette cast at our northernmost science station on this cruise (station CB11 at 79N, 150W), and a little fun. Many people decorated styrofoam cups to send down, on the Rosette frame, to the bottom of the Arctic Ocean (3825 m, the deepest part of the Canada Basin). The tiny cups that come back up are the perfect souvenir from our Arctic expedition.