“This is an extremely important technology. As more and more people start to work up in the Arctic, you get more shipping, you get more oil development, you get more chance of a spill. In order to be able to respond to it you have to have technologies like this,” Jeremy Kasper explained.
The project aims to develop and test inexpensive, reliable means to track ice motion. Buoys that could be deployed to track where oil-infested ice goes. “You could put these around a spill and know exactly where it is and be able to respond to a spill.” Kasper is a research assistant professor with the Institute of Northern Engineering, University of Alaska Fairbanks College of Engineering and Mines, and the director of the Alaska Hydrokinetic Research Center (AHERC).
“In case of an oil spill or any other contaminant spill you want to have something that is pretty simple to get out there, that locals can deploy, whether it’s from a fixed wing or a helicopter. Then you can just have them throw them out on the ice and in the water where there is a spill and you can track the ice and the water.”
While shipping troubles and barges escaping tow lines or moorings rarely receive the sort of national attention Shell’s Kulluk did, they do pose environmental risks. Increasing Arctic resource development makes incidents all the more likely. Kasper described when a Canadian barge escaped its towlines and drifted unmanned along Alaska’s northern coast in late 2014. “They weren’t able to get to it, it was during the storm season. It was during the Fall. So nobody was able to get a helicopter out to it immediately or a plane or a boat or an anything.” Finally the Alaska Department of Environmental Conservation managed to place a tracker onboard. “It’s not like the trackers that we are working with where you can throw them out of a helicopter literally. I think they had to get down on the barge and place this thing gently on there. And they tracked it all the way from the Beaufort to the Chochotka coast.”
What does oil do when it escapes a barge? It becomes a daunting problem. Oil can freeze between layers of ice – ice motion is hard to predict. Oiled ice “Is going to move differently from the ocean, which is going to move differently from the barge.”
Drifting pack ice in the Arctic is on the move. Unlike its (still hard to predict) cousin landfast ice, pack ice is highly mobile. Sea ice motion is driven by wind motion, ocean currents, air-sea heat fluxes, literal collisions with other sea ice, weather conditions, and fresh water discharge from ice melt or river mouths. The motion is complex and pricey to chart on a fine scale. Imaging satellites have limited coverage of the poles; “Repeat passes every day or more,” Kasper said. Radar is limited in range from origin. Buoys carrying lots of scientific equipment like ice mass balance buoys might have upwards of $15,000 worth of sensors on board.
Kasper: “The ice tracker project was basically to test or verify that these very inexpensive ice drifters would be able to accurately track ice motion. The motivation is: we wanted a technology that was easily deployed by first responders.” Ice tracker buoys could track a barge and the oil or oiled ice around it. “I think so far they have been proving to be pretty robust and they would be good for an incident like that.” The ice tracker project was funded by the Bureau of Ocean Energy Management; the Shell North Slope Borough baseline studies program was a co-funder.
The buoys don’t look revolutionary. They’re rotund and white, covered in foam. Pull a small magnet from the side of the buoy and it’s activated. The protective casing houses batteries, a GPS and a device like a satellite phone that allows communication with satellites in low Earth orbit. Visit the manufacturer’s website, and you can command the buoy to transmit its location in various intervals of time.
“Overall they are pretty simple; you can take them, put them on a snow machine, throw them on the ice.”
Kasper was off the coast of Barrow, Alaska, working to deploy buoys over the sea ice with Andy Mahoney, University of Alaska Fairbanks assistant research professor in geophysics. The two placed spaced-apart buoys in two pentagon shapes atop sea ice, then tracked the buoys’ motion. Their tests, compared with data obtained by other sea ice tracking methods, would be used to verify the buoys’ accuracy, toughness and battery capabilities.
“You can change its sampling rate,” Kasper said. The buoys on landfast ice were set to transmit location data every hour or so. “If you wanted to do this for spill response you would want this updating every 5 minutes to really track the ice in real time and help spill responders figure out where things are moving. The idea is, it’s a low cost simple platform that anybody can use.” Kasper foresees “It could be pretty important technology, given what’s happening in the Arctic.”
They threw buoys out of a helicopter. From 40 feet above the ice Kasper estimated that one “Bounced a good 5, 10 feet back up in the air,” after striking solid ice under a couple centimeters of snow. It landed and rolled around a bit. Still worked.
“Overall we are pretty excited, we got 15 of these trackers out in short order, and it was fairly easy. That’s really encouraging.” If they are reliable enough, Kasper estimated “We can put out a lot of them and start making small scale measurements of ice scale deformation.”
The scientists deployed their pentagons in the Beaufort Sea in a mix of first year and multi-year ice. “We expect them to move differently so we wanted to tag a couple of different types of ice,” then track how the sea ice converges and diverges. “The trackers are pretty much spread out in the Chukchi Sea; they started in the Beaufort Sea. Looks like they’ve moved between 70 and 110 kilometers in the course of the 10 days that they’ve been out. So it’s fairly rapid movement,” like a dance of dizzying spirals drifting away from the coast, then back. “The winds are coming out of the west again and they’re actually moving back towards Barrow.”
The scientists are combining the buoys with other tools. Kasper said “We’re hoping to tag features that show up in the radar and then track them after they go outside of the radar mask. And so then you learn about the fate of the ice.” It’s good news. “Since they are very low cost, that allows some new science as well.”
Bounceable buoys tracking sea ice oil spills
Laura Nielsen 2015
Frontier Scientists: presenting scientific discovery in the Arctic and beyond
