August 20: Oh Canada

08-20_IcePackCanadaWe finally succeeded in getting over to the Canadian side of Nares Strait.  Nobody was there to check our passports, of course, but we have changed countries – this transit was all pre-approved by the Canadian border authorities. Getting to Canada was not so easy, as big ice floes and bergs were streaming out of the Arctic Ocean in the strong southward current along the Canadian Coast.

Our oceanographic goal was to measure the water properties across the strait to calculate water flows –the oceanographers call this geostrophy.  We hope to track the relatively warm salty bottom waters from the Arctic Ocean, through deep channels that end up in Petermann Fjord.  Once the warm water gets to Petermann it can melt the ice. With our extraordinary new maps of seafloor bathymetry, we now think we know for the first time the pathways of the deepest water-masses as they snake around a complex network of hills and valleys and spill over into the fjord.  But we really need to sample the waters to be sure. That should happen in the next few days, weather permitting.

Our geologic goals were to map the sea-floor striations that track the flow of long-gone glaciers northward (we think) from Nares Strait or perhaps out of Canada, and to discover where they collided with ice sourced from Petermann Fjord.  By coring the sediments we will determine the history of the various ice streams and water masses over thousands of years, and we will figure out when they retreated back onto land.  It is possible that some of the glacier systems had floating ice shelves similar to modern Petermann Ice Shelf. But these were out in Nares Strait, which was effectively a big fjord of its own, dammed by thick ice to the south and opening as an estuary into the Arctic Ocean.  We would like to know the role of those long-lost ice shelves in supporting the grounded ice during the end of the last ice age, and how fast they disappeared.

08-20_CapeBairdThe biology and beach teams were also active, the latter landing on Cape Baird, Ellesmere Island (Nunavut, Canada) to sample old shells that record the rise of the land above sealevel after the ancient ice retreated. That group was met on the beach by fresh polar bear tracks, followed by what appeared to be fresh wolf tracks.  We presume that the wolf followed the bear, looking to clean up the scraps from a feast.  Very exciting!