Today, as part of this project we flew in a Bell 212 Helicopter about 50 km North of Barrow, out over the sea ice. We set down on some 3m thick multi-year ice and cored and measured depth-profiles either side of a pressure ridge that separated older multi-year ice from some of this season's first year ice. The MY ice is blue, hard and fresh, and the FY ice saline and more plastic/ softer. Just as well the drill died while coring the softer, thinner FY ice!
The thickness of the ice that Oceanographer Mark Johnson is standing on is about the height of the coring barrel. We soon had power drill problems and used the manual head to turn the corer into the ice by hand.
This pic shows the bottom section of the 1.25 m long FY ice core we extracted. The faint coloration at the bottom is actually algae. This thin greeny-brown layer spread over millions of square kilometers, underlies the Arctic food web. The algae get into the thin brine layers than form as the sea water freezes: the salts can't be incorporated into the H20 crystal structure of ice and end up in briney inclusions, pockets and tubes.
Here one of the pilots, Scott, is talking shotguns with me (red), Mark and the other pilot, Anders. We saw no bears or tracks, but did see a bowhead whale breaching to breathe in a lead (open water in the middle of the ice pack), which was actually pretty cool! The lower whaling crews are now cutting trails throug the ice off of Barrow so they can access their wahling camps at the edge of the large lead that runs about 10 miles offshore. This lead is close to the underwater Barrow chanel through which the bowheads migrate both in the fall and in the spring.
No comments:
Post a Comment