ITP 4 Recovery Operations

By the time it was discovered that the ITP modem circuit was not working, it was too late to recover ITP 4 the same year. It became a priority to recover it the next year, as the profiler was probably collecting profiles that could be retrieved. In 2007, the drift of the ITP over the past year brought it close to the cruise track of the JOIS cruise on the CCGS Louis S. St. Laurent. On August 15, a helicopter reconnaissance was unsuccessful in locating ITP4. It was located by the ship on the next day after receiving an updated location, and the recovery operations began on the morning of the 17th.

The way that the icebreaker was positioned in the ice floe allowed for the handling of the recovery gear and people over the side using the ship’s crane. In the morning, everything was loaded on the ice, and a 1 m diameter ice core melted through the 3.0 m thick floe containing the ITP tether cable. After lunch, the ice was removed from the core and the profiler recovered. The profiler had been profiling the entire time since it was deployed, and 698 profiles were downloaded from the underwater instrument.

More information and photos on the recovery are also available at: https://www.whoi.edu/page.do?pid=67521.

The surface buoy for ITP 4 is only partially submersed in the melt pond when it is relocated nearly a year after the deployment.

The wooden staging that was installed under the buoy during deployment seems to only have partially worked at preventing the ITP surface float from melting the adjacent ice.

Kris Newhall and Rick Krishfield guide the melter ring around ITP 4 in order to cut around the package and through the 2.5 m thick ice (in 0.5 m melt pond).

Jim Dunn operates the hydraulic block and Kris Newhall guides the wire to a wire basket by the ship where the recovered mooring wire is coiled.

ITP4 profiler is intact and relatively clean after only one year under the ice, and would finally be able to transfer the 698 profiles it had acquired since then. Photos by Rick Krishfield.