ITP 1 Deployment Operations

ITP 1 was deployed as part of an Ice-Based Observatory cluster with IMB 07949 in 2005. To find a suitable floe for deploying the cluster, a helicopter reconnaissance was undertaken in the afternoon of August 14. One old floe was landed on and drilled with a 2” hand auger; however, the thickness was greater than 5 m, so was too thick. The second floe that was surveyed was relatively small (only about 100 m in length), ridged all around, and had sufficient level area between several large melt ponds. When drilled, it measured 4.6 m in thickness with 55 cm of freeboard so was suitable. The GPS position was obtained and the site was marked with several trash bags filled with snow so that it could be relocated.

By the next morning, the ship was positioned in the lead next to the selected ice floe, where a lone seal was spotted swimming. Between 10:00 and 11:30 MDT (16:00-17:30 UTC), all of the personnel and gear are conveyed to the ice floe in 3 flights and 4 sling loads. While drilling the 10” diameter hole for the ITP we are pleased to find that the ice is much harder than the rotten ice ITP 2 was deployed on last year. The deployment proceeds smoothly and the ITP is completely deployed only 1.5 hours after everything arrived on the ice.

Meanwhile, the helicopter required repairs, so after the IMB installation was finished, all of the deployment gear had to be hauled to an adjacent ice floe and loaded onto the small boat for transportation back to the ship. All operations were complete and everyone was back onboard by 22:30 UTC.

More information and photos on the deployment operation are also available here and at: https://www.whoi.edu/page.do?pid=68120.

Deployment of ITP1 begins with the transportation of the personnel and equipment to the icefloe. Here the 790 m tether spool is delivered by helicopter pilot Chris Swannell.

Kris Newhall, John Kemp, and Rick Krishfield reach the end of a flight section while augering the 10" diameter hole through the ice of the ITP. Meanwhile, Doug Sieberg begins installing the IMB.

Doug Sieberg starts the IMB buoy in the foreground while the ITP deployment continues in the background and Bosun Robert Taylor keeps a lookout for bears.

Winchman Peter King guides the ITP surface package toward the hole while the last segment of the tether is lowered, while a mast for suspending ice sensors for the IMB is assembled.

Doug Sieberg covers the IMB cables with snow to complete the IMB installation. The mast on the left supports an air temperature sensor, a downward pointed echo sounder for monitoring snow depth, and an upward pointed echo sounder (below the ice) to monitor ice thickness. An ice thermistor string protrudes from the ice to the right of the main buoy which takes the readings from all of the sensors (including barometric pressure) and transmits these information back in near-real time.

The deployment team poses at the conclusion of operations. From left: Ryan North, Doug Sieberg, Kris Newhall, Rick Krishfield, John Kemp, Peter King, Waldeck Walczowski, and Robert Taylor. Photos by Chris Linder.