Edge of the Arctic Shelf

Fishing for Moorings
The sky was gray and heavy this morning... the kind of sky that promises snow and blustery winds. Dry powdery snowflakes whirled around the ship as I made my way to the helicopter hangar to bid farewell and good luck to Jim Ryder, John Kemp, and Dan Torres. Their work done, it was back to dry land. Despite the foreboding weather, it was business as usual for the aviation detachment. Both of the HH-65 Dolphin helicopters were airborne by 9AM, safely carrying their passengers to the Barrow airstrip.

The first order of business after the helicopter flights was the recovery of the University of Alaska Fairbanks Barrow Canyon mooring. This mooring gave us trouble in July 2002 when we were stuck in thick brash ice and were forced to delay the deployment until later in the cruise. Last year and this year, though, that problematic ice is gone. September is the most ice-free month in the Arctic, and recently the summer icepack has been receding even further. Little did we know, though, that a different problem was lurking.

Seth Danielson and Jim Johnson didn't notice anything wrong when they triggered the first acoustic release. The mooring responded immediately, indicating that it was still there and that it was in an upright position. Since this mooring is in very shallow (80 meters) of water, they expected the lookouts to see the mooring floats almost immediately. When the minutes ticked by and nothing was sighted, they triggered a second release. The minutes dragged by again, even slower, as they contemplated what this could mean.

"We're going to have to drag for the mooring," Jim sighed.

Last year we also had to drag for one of the moorings. The operation is time-consuming and difficult, plus there is the added danger of damaging the instruments in the process. A pair of anchors are lowered into the water a few hundred meters from the known position of the mooring. Then, the ship steams in a circle around the mooring, laying down a heavy cable on the seafloor. After circling the mooring position, the ship starts reeling in the line. This virtually guarantees that the cable comes into contact with the mooring, hopefully providing enough of a jolt to open the releases. The entire operation takes a few hours.

When the cable started streaming out behind the ship, principal investigator Tom Weingartner took up position on the O-3 level to watch for the bright yellow and orange floats to appear. Tom is one of those folks who has what you call "infectious enthusiasm." No matter how bad of a day you're having, Tom can make you laugh. Today, though, Tom had a very serious look of determination on his face, like he was willing those releases to open. When Sarah Zimmermann yelled out "there it is!" we all breathed a sigh of relief. And Tom was doing more than that; he was jumping up and down and wearing the biggest grin you've ever seen.

I asked Tom to describe how he felt when that mooring appeared:
"On the one hand you feel that you have invested a huge amount of time, effort, and money (both your own and a lot of other people's) for this moment. (I've been involved in SBI since its early planning stages 10 years ago and here was a big part of my data set.) And while you know the chances are quite good that you will get your instruments back, you also know that there are no guarantees. So how do I feel? Like one of those astronomers who send a spacecraft to Jupiter, wait 10 years for it to get there, and leap for joy when it does and sends data back."

The CTD crew is back in action tonight sampling another transect across the canyon mouth. Then it's off north for more CTDs and to recover more moorings (check out the mooring positions on this map). The science crew is also hoping to see some ice and arctic wildlife!