Monday, August 16, 2010

Arctic adventures completed

Another Baffin Island field campaign, more logistically complicated than any I've yet been a part of, is in the books. Everyone is en route back home, uninjured and pleased at accomplishing more than we had ever hoped. The crew was composed of between 5 and 7 people for the past month, including scientists working on 4 distinctly different questions investigating young ice caps that tell the story of climatic cooling related to volcanism over the past 800 years, climate records spanning the past 8,000 years preserved in lake sediment archives, the evolution of the landscape during the last 2.5 million years of glacial-interglacial cycles, and the much longer-term geologic history of the region on billion-year time scales.

We began with 10 days of work based near Pond Inlet and covering nearly 500 km of terrain stretching from near the northern tip of Baffin to the southern edge of the Barnes Ice Cap. Helicopter support made this all possible. After completing all objectives and more before our stay ended, we moved south to the Qikiqtarjuaq region. Bear problems in this region last year led to a new approach, with everyone staying in a nearby cabin. Bear monitors and a helicopter provided considerably safer working conditions and three new faces with our crew for 9 days. Thick coastal fog had us stuck in our tracks for the first few days, but beautiful weather followed, and we accomplished far more than expected.

Hidden within the vastness of this intimidating and inhospitable landscape are geologic wonders that have seemingly defied the erosive powers of repeated intense glaciations. While some of the most impressive fiords in the world attest to the effect ice sheets can have on a landscape, there are countless examples of areas deeply buried by apparently protective ice during glaciations, frozen to its bed and accomplishing no erosion. Sandstone towers 30 meters tall near Eclipse Sound have been carved and scoured by wind and water more extensively than eerily similar towers in the Utah desert. Remnants of granitic outcrops dot hilltops between widely-spaced fiords southwest of Home Bay, covered in deep weathering pits and shaped into rounded knobs reminiscent of the formations in Joshua Tree. Hilltops near the Barnes Ice Cap lack the expected glacial polish and streamlining seen on similar landforms not deglaciated until 5,000-8,000 years ago elsewhere in the region. And streams on the Borden Peninsula flow through deeply-entrenched meanders in canyons showing evidence of only minimal reshaping by glacial ice.

With hundreds of pounds of new bedrock, till, and colluvium samples in hand, the tedious lab work and numerical modeling begins. Measuring the geochemical compositions and terrestrial cosmogenic nuclide inventories of many of these samples will begin to dominate my time this autumn as the irresistible draw of summertime in the mountains begins to weaken.

Here are some illustrative photos of the work we were doing and the landscape in which we were immersed.

Ice caps and highly weathered summit bedrock


Setting up the GPS system to resurvey a transect up the South Dome of the Barnes Ice Cap to update the melt record that will now span nearly 40 years. The ice in the background is the last remnant of the once-great ice sheet that covered much of Canada and the northernmost part of the US 20,000 years ago.


Sampling weathered bedrock on a hilltop in the central part of the island


Small ice caps and big fiords cover the eastern coast of the island


The view from our first camp on a dreary evening


Alexis atop a tor above Dexterity Fiord


Our first camp


Long hours of golden lighting every clear evening


Arctic cottongrass


Mad clouds


High winds higher in the atmosphere, but eerily calm down in our realm


Semipalmated sandpiper


Hidden sandstone towers, one of the biggest unexpected discoveries on a day spent exploring a very atypical Baffin Island landscape


Deep canyons with entrenched meanders were also unanticipated


Heading out to work at 10 pm after a tremendously windy day


Kate ready to head out onto Midnight Lake to find an appropriate core site


The boss man, relaxing in a packraft


Kate midway through our trip down the Salmon River in the packrafts. We hiked out of camp, floated the river and it's rapids (some far bigger than expected!) to Eclipse Sound, and then paddled back through the -1.5 deg water among ice bergs to town.


Kate taking it all in


Back in Iqaluit with far too much gear. Fog stranded us here for a few days because both the helicopter and commercial planes were unable to fly


Once we arrived in Qikiqtarjuak, our Inuit guides took us by boat to the field area. We saw a few Bowhead whales en route


Allen's cabin near Qivitu, our home for 9 days


One of many amazing sunsets


And one of many foggy days that kept us from working for the first few days at Qivitu


Alexis taking a break from digging in the cliffs (containing 2-million-year-old glacial deposits) to watch a Bowhead and Orca fighting in the water


Ma bear and cubs that were unafraid of the helicopter. These bears kept heading upwind toward the lake where Chris and Kate were coring, so the helo pulled them out to avoid any problems.


Alexis and Chris coring Kivitoo Highlands Lake


We visited a few dozen ice caps like these, which have been frozen to the underlying bedrock since they formed sometime in the past 800 years. As they melt, moss and lichens are reexposed and can be dated using radiocarbon to determine the age of the ice cap.


Alexis logs in a sample location


Some mountain tops in this region felt amazingly similar to Joshua Tree


Evening light


Returning to the cabin after working farther north for the day


More breathtaking fiords


A sense of scale is lacking a bit here, but the walls on the left side of Okoa Fiord are at least 1,700 m tall


This was one of my favorite views of the entire trip


The helo pilot explores the area while we collect bedrock samples


Everyone working late into the night


Kate and Chris show off the first of two sediment cores they pulled out of 22 m of water on Kekerturnak Lake.

4 comments:

Chris said...

Fascinating stuff Kurt. Would love to see the Arctic Cotton Grass. Thanks for sharing buddy.

Dave said...

Wow. And those towers, whodathunk.

Was there a lot more (any?) flowing water in the area in the past?

Dave Harris said...

Kurt, I think you have the most interesting job on the planet! Thanks for all the images, and going into at least a tiny bit of detail on what you do up there. Fascinating stuff. There are a few shots (including your favorite) that look like my backyard. That canyon shot looks like a finger of the Virgin gorge.

Kurt said...

Dave C - not sure about flowing water, but those towers have been covered by thick glacial ice for about 90% of the last 2.5 million years if they predate the onset of glaciation. We'll see what the cosmogenic nuclides in those rocks have to say about their age...

Dave H - My job is amazingly enjoyable. The pay is crap, but it's got so many other perks that I'd probably do it for less (but shh, don't tell CU).