Wednesday, July 17, 2013

July 17, 2013 - Week 3 in Svalbard

During this week, our class traveled to Svea located in Van Mijenfjord, southeast of Longyearbyen. Svea is a mining settlement, originally founded in the early 1900s by a Swedish mining company; in fact the name Svea is the old name for Sweden. The settlement accommodates people working in the mine or in the nearby facilities; approximately 300 people live there but no one stays permanently. Miners work shifts of 12 hours a day and live in the settlement since there is no public transportation in and out of Svea. The workers commute on a company-owned aircraft from Longyearbyen and stay for few days in Svea and then fly back home to Longyearbyen for a few days off.

We had two main goals in Svea, the first one was to look at glacial sediments deposited by Paula Glacier, a glacier that ends directly in the water of Van Mijenfjord and has experienced glacial surges since the last glacial maximum, approximately 20,000 years ago. A surge is a rapid event during which the glacier advances at fast velocities while “pushing” and depositing sediment at its front and flanks. The second goal was to study modern Arctic tidal deposits in Braganzavågen, an enclosed bay just east of Svea and connected to Van Mijenfjord by a short channel. The enclosed bay formed during the last glacial maximum when Paula glacier was far out into the fjord and formed an end moraine that blocked the exit of water from rivers coming into the bay, forming a dam lake.  Part of the end moraine is still there but water can get in and out of Braganzavågen since the glacier has retreated. The water depth is very shallow, close to 20cm deep, even shallower in some areas, and here is where tides come into effect since the tidal range is close to 2 m in this region.

View from the aircraft flying into Svea, which can be seen in the background. The photo shows the remains of the end moraine which separates Van Mijenfjord (on the left) from Braganzavågen (on the right).
Some of the buildings from Svea, in front of them is located the end moraine. The distance between the buildings and the end moraine is approximately 2km, where waters from Van Mijenfjord and Braganzavågen mix.
“Welcome to Svea” sign at airport. Miners use this airport several times a day to travel to and from Longyearbyen.  

 The invited lecturer for the week was Dr. Eiliv Larsen from the Geological Survey of Norway. He is an expert on arctic glacial deposits and geomorphology and has studied the Svea region. On Monday, we only had a short morning lecture on glaciers and their deposits, as well as a short introduction to the research area. The afternoon was used to pack for our trip and to get all the necessary equipment from UNIS.

On Tuesday morning we took a short flight, along with a few miners, to Svea. The flight was about 15 minutes long; it took more time to load the plane than the time we spent on the air. We arrived to a very small airport, with only one building and the control tower. UNIS rents a house that has been modified as dorms and this is where students and faculty stay when visiting Svea. In the afternoon, we drove around the area to get familiar with the geology of the region. The most impressive feature was Slak glacier that drains into Braganzavågen. Interestingly enough, the entry to the mine is right next to the glacier.

Student gear, sampling devices, shovels, and riffles to be used in the field.

The following day we ventured into the glacial deposits right next to Van Mijenfjord. The area is characterized by hummocky structures and the surface sediments have been interpreted as reworked marine sediments. We had an interesting discussion on some glacial deposits that present folding, which is possible because the deposits are very stiff due to the compression of ice. One of the hypotheses for the folding of the structure was ice coming from two different sources and therefore compressing the rigid deposits in two directions. 
Students and professors describing and discussing beach deposits, Braganzavågen on the background.

At the beach, coal fragments that have been carried by currents from the nearby mine. In the background, hummocky structure of glacial deposits with no vegetation cover.
Students describing intertidal bar deposits. This particular bar has not been covered by water in a long time since vegetation is currently growing on it while the surrounding channels are active. 

We spent Thursday all day walking on mud, which is harder than it sounds, especially if the mud reaches up to your knees; in Braganzavågen this is the case. We were divided into groups to study the different aspects of the tidal flat environment; tidal channel, intertidal bars, and supratidal bars. Relatively few studies on tidal systems in modern glaciated areas have been completed; surface ice, permafrost, and the minor (if any) biogenic activity are some of the features that differ from low latitude regions. The end product of our observations this day was a term paper in which we all worked over the weekend. Even with the limited time in the field area we were able to identify key features for tidal flat environments like mud drapes and sediment fining patterns. There were also a couple of interesting features in the area; algal mats, that look like wet, wrinkled paper, and superimposed ripples, these possibly formed by currents at 90° from each other creating a square net-like configuration on the surface of the intertidal bars.

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