Feature: Greenland Thaw

Measuring Change

Reflections of a Changing North

by | 8.22.2014 at 8:48am
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View from our small Poco 500 fishing boat as we skirted through the ice to collect samples. (Photo M. Turrin)

View from our small Poco 500 fishing boat as we skirted through the ice to collect samples. (Photo M. Turrin)

No one ever leaves the field the same way they entered it. Yes there is a new layer of mud on equipment, the expected wear and tear on your personal gear and your physical being, but that is not what I am referring to. I am acknowledging the intangible shift in perspective from a deepened understanding and a broadened vision that has been provided by the experience and beyond that the questions that drive the next field campaign.

Fishing and hunting is still the main livelihood of the Kullorsuaq community.  This type of small Poca 500 with a hand winch was what we found along the waterfront. (Photo M. Turrin)

Fishing and hunting is still the main livelihood of the Kullorsuaq community. This type of small Poca 500 with a hand winch was what we found along the waterfront. (Photo M. Turrin)

The end of any field campaign is bittersweet. The adrenaline rush of the data collection phase slows to a more normal rhythm of daily life. There is a change from an unwavering focus on the many details of the project with a hard push day after day to extract as much out of the field time as possible, to a position of intense reflection. Was the campaign a success? Were we able to accomplish what we had hoped? Did we come away with the data we wanted? What did we learn? Should this project be repeated? or adjusted? perhaps expanded?

Our Reflections –

The Kullorsuaq waterfront. (Photo M. Turrin)

The Kullorsuaq waterfront. (Photo M. Turrin)

Establishing Connections

Our fledgling partnership has shown there is both a willingness and an interest among the local Greenlandic to work with scientists in collecting measurements. There is an aptitude for working with the instruments and a desire by them for the collected data on temperatures at depth in their local fjords to build a broader understanding of their environment. Both the science team and the Greenlandic fishermen see this data as important to planning for the future.  They are hopeful it will provide them insights to direct their fishing practices, which in this traditional community remains their main livelihood. We are hopeful it will provide evidence of processes driving change in the Greenland tidewater glaciers.

The Kullorsuaq fishermen are seen moving through the water at all times of the day and night. While we were there fishing conditions were difficult and fishermen were traveling well south to drop their lines. (Photo M. Turrin)

The Kullorsuaq fishermen are seen moving through the water at all times of the day and night. While we were there fishing conditions were difficult and fishermen were traveling well south to drop their lines. (Photo M. Turrin)

The Kullorsuaq fishermen have told and showed us that they will adapt to change in the north. We can help them adapt by providing them information that assists their choices and adjustments.

Deeper Understanding

Alison Glacier flows into Melville Bay just behind the rocky foot of Kullorsuaq (visible at the top of this photo). The bits of ice debris are loosely jumbled at this distance from the glacier front unlike at the mouth where they are densely packed. (Photo M. Turrin)

Alison Glacier flows into Melville Bay just behind the rocky foot of Kullorsuaq (visible at the top of this photo). The bits of ice debris are loosely jumbled at this distance from the glacier front unlike at the mouth where they are densely packed. (Photo M. Turrin)

When we arrived in this small community there were no water temperature measurements inside the fjords for this  area of Greenland.  We hoped to collect water column data that would tell us if this northwest corner of Greenland was being affected in the same way as other parts of Greenland, with warm Atlantic Water flowing in at depth. Bathymetry (bottom depth) measurements did not exist in this section of Greenland’s coastline and it turned out the area was much deeper than we had expected. When we planned the project the little data that is available showed depths of 400m, yet we lowered our instrument approximately 500 meters and only three of our casts reached bottom. The Kullorsuoq fishermen told us that in front of the glacier it is over twice this depth which they have learned from lowering their fishing line.

A preliminary look at one of our data casts shows the temperature dropping and then warming as the depth increases, a result of intersecting the different water masses. (Credit D. Porter)

A preliminary look at one of our data casts shows the temperature dropping and then warming as the depth increases, a result of intersecting the different water masses. (Credit D. Porter)

While we were not able to get data the full extent of the water column the measurements we collected confirmed that, as in other areas of Greenland, warm surface water (>4°C) is layered on top of colder fresh Polar Water (<-1.5°C), and below this, from about 200 m (700 ft.) and below, flows warmer Atlantic Water. As our equipment didn’t allow us to go the full water depth we don’t know how warm it  gets, but we know it exceeded 1.7°C and was still rising at the depth of the cast. This warm deep water is affecting glaciers like Alison that sit in deep fjord troughs by melting the ice at the base of the glacier, causing weakening and retreat.

Moving Forward

Map of the series of casts completed in front of Alison Glacier and Hayes Glacier to the north. Red was day 1 of sampling, Green was day 2.  (Credit D. Porter)

Map of the series of casts completed in front of Alison Glacier and Hayes Glacier to the north. Red was day 1 of sampling, Green was day 2. (Credit D. Porter)

Our sampling plan was adjusted to deal with the ice conditions in the field. We had to shift our collection points to work around the mélange in front of glacier. We focused the first day (shown in red) on getting as close to the ice front as possible, collecting a ‘transect’ or line of measurements, and surveying the smaller channels. Day 2 (shown in green) we extended the transect from day 1, tested for pathways to the outer shelf, and tested one of Hayes Glacier (just north of Alison) outlets paths, and collected some repeat measurements from Day 1 to see how conditions vary with time and tides.

Moving through the water to collect more samples is done by boat for summer sampling, but the conditions will be very different in the winter when dog sledges will be needed. (Photo M. Turrin)

Moving through the water to collect more samples is done by boat for summer sampling, but the conditions will be very different in the winter when dog sledges will be needed. (Photo M. Turrin)

We have plenty of data to analyze but in the future collecting data in other seasons and locations would be beneficial. According to our Greenlandic partners getting winter measurements in Kullorsuaq is possible using their dog sledges to move the instrument. Early spring would offer interesting conditions as well. The local fishermen are anxious to continue to work with us, and we hope to be able to continue and build on this partnership.

It is always bittersweet to leave an area where you have built connections and learned so much.  (photo M. Turrin)

It is always bittersweet to leave an area where you have built connections and learned so much, but we look forward to more opportunity to work together. (photo M. Turrin)

Qujanoq (kwee-yan-ok) to our new Greenlandic friends – Thank you.

Project Information: Dave Porter and Margie Turrin were in northwest Greenland working with local community members to collect water column temperature profiles. The Leveraging Local Knowledgeproject will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.

The project is funded by the Lamont Climate Center with support from the NASA Interdisciplinary Program and logistical support from NSF.

http://www.ldeo.columbia.edu/~dporter/Kullorsuaq/

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