Svalbard: Theses
Permanent URI for this collection
Browse
Recent Submissions
Now showing 1 - 20 of 42
Item Open Access Calibrating annual sedimentation in a glacial lake Lake Linné, Svalbard, Norway(2012-07-03) Snyder, SydneyThis study will focus on the most recent depositional year, fall 2010 through summer 2011. The study is a continuation of previous projects and investigates modern sedimentation in Lake Linné in order to formulate a relationship between sedimentation and environmental climate variables. Not only was the amount of total accumulated sediment anomalously low during last season, but the proportions of sediment attributed to fall deposition and the spring melt season were unconventional. Sediment varves from the most recent atypical depositional year have the potential to complicate the extensive varve record. Misinterpretations of seasonal varves may therefore convolute the record of past environmental conditions, thus a clear understanding of this contemporary record is essential to correctly interpreting past High Arctic climate conditions.Item Open Access A Karst Lake System in the High Arctic: A Case Study at Linnédalen, Svalbard(2012-07-03) Cohen, SaraThe island of Spitsbergen, which makes up the largest portion of the Svalbard archipelago, is located in the high arctic, between 74° and 81° north. This high latitude Arctic environment provides the means for widespread permafrost formation. Currently, Svalbard is 60% glaciated, leaving 40% and approximately 25,000km as a permafrost and periglacial environment (Humlum, 2003: 199). Glaciers, permafrost, and periglacial features can all be widely observed on Svalbard. This study will look at a system of karst lakes found in an active and continuous permafrost zone on Svalbard. Karst is a globally spread phenomena which commonly occurs in regions consisting of carbonate rocks and evaporites when weathering and erosion occurs (Ritter et al, 2006: 407). Although karst is found in every region on earth, it is mostly found in temperate or tropical climates, because moderate temperatures, humidity, high precipitation, free flowing water, and high vegetation levels are all seen as favorable factors for formation (Ritter et al, 2006: 412). Karst is not nearly as frequently found in Arctic climates, due to the typical Arctic conditions of extremely low temperature, low precipitation, frozen water, and low vegetation being unfavorable for the formation of karst features. There have been relatively few studies of karst features occurring in High-Arctic environments. These studies have been mostly concentrated in Canada, the United States, Russia, and Svalbard. It was originally thought that only thermokarst features could form in the arctic, and true karst could not exist, because the chemical weathering needed to form karst was prevented by permafrost (French, 2007: 69). Thermokarst is not related to karst, and has nothing to do with the solubility and weathering of limestone or evaporites. The relationship of the two names can be explained, because the thaw of permafrost leads to thermokarst features, including the collapse, subsidence, erosion, and instability of the ground surface, which would appear similar to the results of true karst (French, 2007: 186.). It is now known that true karst can exist in the High-Arctic. Studies by D. C. Ford have resulted in the development of a model for karst existing in permafrost zones, with the groundwater circulation and solution being limited to the active-layer, allowing for shallow karst terrain (French, 2007: 69). The previous studies of karst systems in the High-Arctic have been done on karst systems in Svalbard, the United States, Canada, and Russia. In a study done by I. D. Clark and B. Lauriol at the Firth river basin, in the Yukon, Canada, the drainage of water from karst systems is proven to flow through taliks, and then resurface in the growth of an aufeis. In Svalbard, Northeast of the study area, a karst system has been studied by O. Salvigsen, Ø. Lauritzen, and J Mangerud. Here, the authors have only been able to conclude that the water must drain below the active layer of two meters, but cannot determine the mechanisms which make this drainage possible. A study by O. Salvigsen and A. Elgersma in Svalbard focuses on the same area as this study. They were able to determine that the lakes in the study area were true karst, but did not attempt to date Sara Cohen: AG-212 Term Report 4 the formation of the karst. They did, however, try to determine how the water drained through the karst system, by performing dye tests and digging pits in the area, but were unsuccessful. In order to further the understanding of karst systems in High-Arctic climates consisting of active permafrost zones, this report will take a comprehensive look at a karst lake system located in Linnédalen, Svalbard. The report will include a geomorphological map created after a month long period of observations in the study area which aims to catalogue the periglacial features and processes occurring in the area. The report will also attempt to come up with an explanation of when and under what conditions the karst lake system was formed. Finally, the report will include an interpretation of how the water in the lakes drains vertically through the permafrost. This report is meant to be the first part of a continuing study of the karst lakes in Linnédalen. At the end of the report there will be a plan for the continuation of the study.Item Open Access Slope Processes of Linnédalen, Spitsbergen: Sedimentation through Avalanching(2012-07-03) Farnsworth, Wesley R.During late July and the beginning of August 2010 a field study on slope processes was developed in Linnédalen, central Spitsbergen (figure 1). The aim of this project is to analyze slope processes in the region focusing primarily on snow avalanching as a function of sedimentation. The study will combine and correlate meteorological data, time-lapse camera imagery and prior studies in the area. The objective is to gain an understanding of the valley wall sedimentation and the significance of snow avalanching as a means of clast transport in Linnédalen. A focused study will be conducted on the eastern and western flanks of Griegaksla with a comparative analysis of slope characteristics with regards to rock type, grain size and slope features. The study also involves mapping the clast size distribution of five talus cones in the Linné valley using Arc GIS. Avalanche activity will be determined through time lapse photo imagery and Tinytag shock logger activity. Avalanche periods will also be compared to meteorological data. Twelve natural sediment traps are monitored between the eastern and western flanks of Griegaksla indicating yearly sedimentation. This study focuses on whether snow avalanching the predominant mechanism in the regional sedimentation, and what factors control sedimentation. The project will also try to hypothesize how slope processes evolved through time and what will happen in the future.Item Open Access The Role of Underflows and Weather on Sediment Distribution in Glacial-Fed Lake Linné, Svalbard, Norway(2012-07-03) Zamora-Reyes, DianaClimate change is without doubt one of the most problematic issues that society will need to find a solution in the future to prevent further damage. According to the IPCC’s fourth assessment report in 2007, recent climate change has been due to an increase in greenhouse gases caused by humans. Some parts of the world have and will further experience an increase in temperature; this might trigger catastrophic events such as the extinction of polar bears in the arctic regions or desertification in Southwestern US. One way to understand how the Earth will react to this abrupt change is to find out how she has reacted in the past. These past-climate reconstructions are an important key to understand and predict future climatic variations. The High Arctic is currently a vulnerable area being largely affected by climate change. It’s an excellent place to reconstruct past climates due to of its small human population and because it’s completely driven by natural forces. The High-Arctic, especially areas such as Svalbard, will have an increase in temperature of about 8°C by the end of the 21st century (Øseth, 2011). This warming will likely have a huge impact on both local and global plant, animal, and human populations due to the decrease of ice sheets, ice caps, glaciers and snowpack (Øseth, 2011). One of the various proxies presently used to reconstruct past climates are arctic varved lacustrine sediments (Bradley et al., 1996; Overpeck et al., 1997; Lamoureux et al., 2002). Sediments deposited by glacial-fed lakes in the Canadian High-Arctic have received a lot of attention since the late 70s and remain a currently used proxy (Carmack et al., 1979; Smith, 1981; Gilbert and Church, 1983; Smith and Ashley, 1985; Snyder et al., 2000; Lamoureux et al., 2002; Lewis et al., 2002; Cockburn and Lamoureux, 2008, among others). Linnévatnet is an arctic lake monitored by the Svalbard REU since 2003 and contains lacustrine sediments that have laminations which seem to be strongly influenced by season; coarse silt to fine sand in the summer and clay during the winter (Svendsen and Mangerud, 1997; Snyder et al., 2000, McKay, 2004; Motley, 2006; Roop, 2007; Cobin, 2008; Arnold, 2009). Young laminated sediments can be calibrated using current weather data to see how it’s affecting the sediment distribution and use this relationship in older sediments to reconstruct past climate. One factor that influences where and how much sediment will be deposited in an area of a lake is the frequency of different lake processes such as overflows, interflows, underflows and homopycnal flows (described in section (1.3). In Linnévatnet the spring melt occurs during late-June to mid-July. As in other lakes in the Canadian High-Arctic, it is the most important event of the year due to the high input of discharge of nival melt and sediment (Braun, et al. 2000; Gilbert and Butler, 2004; Cockburn and Lamoureux, 2008). The purpose of this project is to determine the frequency of underflows and how they may influence sediment distribution in Linnévatnet. Another goal is to see how underflows are related to weather patterns and inflow temperature during the spring melt. This will be done by using different sets of data gathered from the lake during and a weather station near Linnévatnet during July 2010.Item Open Access A Characterization of the Biology and Nutrient Cycling of Two Glacial Lakes in Isfjord Radio, Svalbard(2012-07-03) Magnabosco, CaraDue to the fact that lakes in the high arctic are only exposed for two to three months out of the year, very little is known about the microbiology and nutrient cycling that occur in this region. Of greatest interest in these high arctic regions are the primary producers that control the majority of the biogeochemical cycling and carbon dioxide sequestration of the region. Therefore, it is important to understand how industrialization of the 20th and 21st centuries is affecting these delicate and vital ecosystems. This study explores two glacial lakes in the high arctic region of Svalbard. In order to gain insight on the nitrate and phosphate supply ratios driving primary production in the region, a series of nutrient enrichment experiments (mesocosms) on eleven locations throughout Isfjord Radio, Svalbard were performed. The results of these experiments reveal that the primary producers of this region are highly responsive to the increased nitrogen deposition from the burning of fossil fuels in North America and Europe. In particular, this study shows that, the past decade alone, diatom diversity within these two lakes has significantly decreased in response to the increased nitrogen loading of these freshwater systems.Item Open Access Cryoconite Evolution and Formation on an Arctic Glacier Surface: A Case Study and Model(2012-07-03) Hittson, TerraCryoconite holes are vertical cylindrical holes that form on glacier surfaces due to the lower albedo of sediments. Cryoconite holes exist on Linn ebreen, Svalbard over the entirety of the glacier. They preferentially melt below the surrounding glacier surface and eventually create standing water above them. In this study, six cryoconite holes were created by placing sediments on the glacier surface and observing their growth and movement for a period of fourteen days. They ranged from 2.0 cm wide with a depth of 0.5 cm to 7.0 cm wide and a depth of 2.0 cm. The greater the size of the cryoconite, the more it enhanced the melting of the surrounding surface both where it was initially placed and when it traveled down glacier. The largest cryoconite hole nished the two-week period 1 m down glacier from its initial placement and melted nearly 10 times the area of glacier ice as its own initial area. I hypothesize that this is due to the hydrologic cycle at work on the glacier. In order to look at this, we modeled how the cryoconite holes would form using the lower albedo of the cryoconite and the sun's revolution about the fi eld site.Item Open Access Analysis of Varved Sediment and Weather Relationships in Lake Linnè, Svalbard(2012-07-03) Wei, JeremyThe recent debate involving climate change has become increasingly important in the past decade. Arctic environments are important locations for study as they are particularly sensitive to climate variations. Proglacial lake sediments, particularly varves, such as those found at Lake Linnè, on the island of Spistbergen, Svalbard, demonstrate this sensitivity as they are driven by glacial ablation. The correlation of cores from different lake locations has served to identify and discard inconsistencies in the varve record. The relationship between measured varve thickness and weather parameters is based on meteorological records for the past century, and demonstrates the responsiveness of varves to changes in climate and weather as glaciers are sensitive to these changes. The measuring and counting of varves allows the construction of a chronology which can therefore serve as a climate proxy for Svalbard for the past century. The varve analysis from this study reveals the complexity of the sedimentation in Lake Linnè, and attempts to define the other likely factors which contribute to varve deposition. Overall, the assembled climate relationships reveal varves which can be linked to changes in weather and climate patterns, and the possibility of increased sensitivity of the Lake Linnè proglacial system to climate change.Item Open Access The Glaciofluvial Environment of Linnébreen, Spitsbergen, Svalbard(2012-07-03) Pendleton, Simon L.Suspended sediment concentrations (SSC), meltwater discharge and local climatic conditions of the Linné glaciofluvial system were monitored from July 21 to August 9, 2010 in order to determine the temporal relationships between local climate, glacier melting and sediment production. ISCO water samplers were installed along the main meltwater channel to record SSC. SSC was directly related to discharge of the glaciofluvial system, which was in turn dependent on melt of the Linné glacier. The relationship between SSC and climatic conditions can be linked to the rate of glacier melt, which is in turn controlled by local climatic conditions. Of all the observed weather conditions, precipitation had the highest impact on glacier melt and discharge and therefore had the highest correlation to SSC. During periods without precipitation, solar radiation was the greatest influence on glacier melt and SSC. Measured SSC and calculated sediment load for the season from the Lower (distal) site was substantially less than the measured SSC and calculated sediment load at the Upper (proximal) site. The differences between the two sampling sites indicate that the glaciofluvial system immediately downvalley of the glacier is acting as a sediment sink. This study has established that increased SSC is largely due to increased precipitation. The presence of a pro-glacial sediment sink interrupts the sediment signal produced by the glacier and complicates the sediment record downvalley in Lake Linné.Item Open Access USING SEDIMENT GEOCHEMISTRY, PARTICLE SIZE DISTRIBUTION AND REMOTE SENSING TO STUDY PROVENANCE IN THE KRONERBREEN/KONGSVEGEN GLACIERS, WEST SPITSBERGEN, SVALBARD(2012-07-03) Zamora, Hector AlejandroSediment provenance at the Kronerbreen/Kongsvegen glaciers in Spitsbergen can be used to understand the effects that climate change can have on the sedimentation in fjords, and streams at northern latitudes. These sediments are directly related to glacial processes and reflect the conditions under which they formed. Such conditions are sensitive to global climate change, which is amplified in northern latitudes, creating a unique environment for climate change research. Quantitative provenance studies have never been carried out in the Kongsfjorden before, and can provide data for a better understanding of glacial processes and dynamics, and changes in erosional conditions. Particularly, sedimentation rates and sediment grain size distribution can help unravel the glacial history of the area. This study will focus on analyzing the grain size distribution of the material being deposited by the mentioned glaciers and finding the source rock of these sediments. Fine sediment was transported by streams and upflows identified in the field, and fed by the glaciers melting ice. On the other hand, coarser material ranging from cobble to boulder size was deposited by ice, moraines, and alluvial processes. Sediment and rock samples were collected during the months of July and August 2009, along the terminus of the glacier, and in the surrounding areas, respectively. Grain size analysis was performed on the samples using a Malvern Mastersizer with the resulting in different groups showing a change in particle size and sorting depending on the location along the glacier. This analysis is important as mineral composition and transportation is influenced by grain size.Item Open Access Glaciomarine Oceanographic and Suspended Sediment Dynamics, Kongsbreen system, Svalbard(2012-07-03) Marshburn, HannahQuantifying estuarine circulation and the resulting sediment dynamics of tidewater glaciers is crucial to developing an understanding of these dynamic systems, and their response to climate and sea level change. This study characterizes oceanographic conditions and suspended sediment loads resulting from glacial meltwater in proximal distance to the glacier terminus of the Kronebreen-Kongsvegen system, Kongsfjorden, Svalbard as a component of the Svalbard REU project. The study was conducted during July and early August of 2009, coinciding with maximum melt water volumes induced by elevated summer temperatures, and approaching the spring tidal maximum. Major fjord, oceanic, and glacial- induced brackish meltwater plumes were identified and evaluated for suspended particulate load through CTD scans, optical back scatter (OBS) readings, and water samples taken in perpendicular transects roughly 200-1000 m from the glacial termini. Sub-glacial upwelling systems on opposing sides of the glacial face were targeted for analysis and comparison. The control of tidal fluxes¬¬¬ on sediment and interflow mixing was examined. The fjord is an example of a system with active marine glaciers transitioning to terrestrial systems, vulnerable to circulation changes. The estuary consists of a three layer stratified system. A turbid shallow estuarine brackish mixing layer was identified, with temperatures ranging between 3-4oCelsius and practical salinity ranging from 15 to 31, a result of glacial outwash. An intermediate Atlantic interflow was identified through a warm saline water tongue at depths of 15-20 meters, with mean temperatures between 4-5o Celsius and salinity of 31 to 32. The fjord bottom water was characterized by a drastic temperature decrease at 30 meters from 5 to 1.2o Celsius over a 10-20 meter interval, with salinity constant at 33-34. Suspended particulate loads from water samples and OBS values were higher in the unrestricted sub-glacial upwelling plume system as opposed to the system in the semi-enclosed delta. The surface mixed layer contained the highest suspended particulate matter, with a mean sediment concentration of 0 .1351 kg/m3, compared to the intermediate and bottom water values of 0.06801 and 0.04376 kg/m3, respectively. Data during ebb tide phases indicate reduced water column stratification. Fjord waters and currents are strongly driven by thermohaline convection cycles due to their partial enclosure and protection from open ocean winds and waves. Research characterizing density driven mixing properties of inner fjord basin water columns is limited. Data generated in this study can be used to investigate the effects of glacial outwash, comprised of freshwater and sediment, on fjord circulation. Understanding how glacial meltwater is exported from fjords and interacts with ocean-climate systems is critical to hypothesizing future climate behavior.Item Open Access Characterizing fjord oceanography near tidewater glaciers Kronebreen and Kongsvegen, in Kongsfjorden, Svalbard(2012-07-03) Rajagopalan, Daksha M.In recent years, warmer Atlantic-origin waters have intruded into Svalbard's west- coast fjords. To predict the e ects of the TAW (transformed Atlantic water) intrusion on the ice margin of tidewater glaciers, a detailed understanding of fjord circulation is important. While the general fjord circulation of Kongsfjorden, Svalbard, is well- understood, water masses closest to the ice margin { and directly responsible for sub- marine glacial melt { are more di cult to study. To characterize the water masses and interpret fjord circulation at the calving-fronts of glaciers Kronebreen and Kongsvegen, Svalbard, oceanographic eldwork was conducted along ve primary transects, with the view to account for tidal in uences as well. CTD (conductivity, temperature, depth) devices with attached OBS (relative turbidity) sensors were used to collect data that range from 200 m to 1.7 km from the ice face, between 22 Jul and 6 Aug 2011. Current velocities were also estimated using drogues constructed while in Svalbard. The data show signi cantly variability in the water column strati cation between just days. In addition to the tidal cycle, winds and other factors also appear to play a major role in glacial discharge streams and circulation. A comparison with data collected in the same region in Jul 2005 (by Trusel et al. 2010) show the 2011 Intermediate Water (IW) at depth to be warmer than the 0 local water (LC) that was observed at comparable depths in 2005. These two layers lie above the TAW and may be warmer as a result of convection with increased TAW waters. Increased intrusion of Atlantic-origin waters after 2005 are likely to have warmed the waters in the inner fjord of Kongsfjorden, indicating that the ice margin of tidewater glaciers in Kongsfjorden are susceptible to heat fuxes from North Atlantic water intrusions.Item Open Access Gravity Core Geochemistry at the Kronebreen Glacier, Svalbard, Norway: Quantifying Climate Flux in a Glacimarine Setting(2012-07-03) McGregor, DarenDarren's thesis looks at the geochemistry and lithosstratigraphy of six cores recovered along a proximal to distal transect in Kongsfjord.Item Open Access Short-term Glacial Calving Processes at Kronebreen-Kongsvegen, Svalbard(2012-07-02) Tinder, Phaedra CalistaCalving is an important component of glacier mass loss, but it remains difficult to model and directly influences sedimentological processes at the ice margin. As part of the Svalbard REU, this study aims to characterize the short-term calving processes at a tidewater glacier and establish a baseline dataset to which future and contemporary studies can be compared. The study was conducted during two weeks in July and August of 2009 at the head of Kronebreen-Kongsvegen glacier system in Kongsfjorden, Svalbard. Two water pressure gauges deployed on the north and south sides of the fjord, adjacent to the glacier face, logged water levels at ten-second intervals. Air pressure and fjord salinity were used to convert water pressure to water depth. The higher frequency water level changes were analyzed to identify large calving events and study their frequency, size, and origin along the calving front. The timing and magnitude of calving events also were compared with potential external forcing mechanisms, such as weather, tidal stage, and local water depth. The pressure-logged wave records were calibrated and confirmed by comparison with observational data from visual logging of calving events at the site. The 15-day study period occurred during the height of the summer melt season. Over the entire record, the frequency of calving events appears to follow the changing tidal amplitude, with reduced calving after the neap tide interval. The observed relationship between calving frequency and tidal stage has been documented at Alaskan glaciers and other locations, and linked causatively by the explanation of increased circulation at the glacier front, as well as the destabilizing effect of buoyancy on the ice front. Fjord water depth at the glacier front influences the formation of “calving bays” where a majority of calving events were observed and the majority of ice loss occurred, as confirmed by satellite imagery. This project is part of a multi-year study of the response of Kronebreen-Kongsvegen to climate change, and also addresses the problem of constraining calving mechanisms and dynamics. Proper methodology in association with deployment of multiple water depth/pressure loggers placed close to a calving glacier terminus are recommended as an effective means of studying calving processes at a high resolution over various time intervals.Item Open Access Relationships among Weather, Glacial Ablation, and Fluvial Processes, Svalbard, Norway(2009-07-14T14:26:50Z) Gerke, EmilyEmily's project examined the relationship between measured weather conditions, glacier mass balance and sediment transport in the meltwater system of the Linne' Valley during the 2005 ablation seasonItem Open Access Fjord Sedimentation Associated with a Submarine jet and Plume Discharging into Kongsfjorden, Svalbard, Norway(2009-07-14T14:26:49Z) Trusel, Luke; Brigham-Grette, JulieLuke, studied the modern processes associated with meltwater discharge along the front of a calving tidewater glacier (Kongsbreen) near NyAlesund, Svalbard, NorwayItem Open Access Glacial Ablation Dynamics and Sediment Flux at Linnèbreen, Spitsbergen(2009-07-14T14:26:49Z) Helfrich, Eric; Brigham-Grette, JulieEric's project focused on the glacier ablation dynamics and sediment release from the Linne' Glacier during the 2006 ablation season.Item Open Access Sedimentation in High-Arctic Lake, Linnévatnet, Svalbard: A Modern Process Study Using Sediment Traps(2009-07-14T14:26:49Z) Arnold, Megan; Retelle, MikeMegan studied the sediment trap records from Lake Linne' that were deployed during the 07/08 sedimentation year. She related textural changes in the various sediment traps to one another and to measured weather parameters, water temperature and turbidityItem Open Access Interpretations of Sediment Recovered from Lake Kongress Vattnet, Svalbard(2009-07-14T14:26:48Z) Ream, Jesse; Werner, AlJesse studied three short and one long core recovered from Lake Kongress. She documented down core changes in LOI, carbonate content and magnetic susceptibility. Her cores were recovered in 2005.Item Open Access Controls on sediment flux in the Linne' River(2009-07-14T14:26:48Z) Mattell, Nora; Detheir, DavidNora studied the processes associated with sediment flux down the Linne' meltwater system during the summer of 2005. She related suspended sediment load to weather parameters, glacier ablation and river stage/dischargeItem Open Access A Reconstruction of Equilibrium Line Altitudes of the Little Ice Age Glaciers in Linne’dalen, Western Spitsbergen, Svalbard(2009-07-14T14:26:48Z) Bates, Steven; Christiansen, HanneSteve's project was directed at reconstructing the ELA depression during the Little Ice Age for the Linne' Glacier and several small cirque glaciers on the west side of the Linne' Valley
- «
- 1 (current)
- 2
- 3
- »