ALBERT

Description: The Arctic is warming, but the impacts on its coasts are not well documented. To better understand the reaction of Arctic coasts to increasing environmental pressure, shoreline position changes along a 210 km length of the Yukon Territory mainland coast in north-west Canada were investigated for the time period from 1951 to 2011. Shoreline positions were extracted from georeferenced aerial photographs from 1951, 1953, 1954, 1972, 1976, 1992, 1994, and 1996, and from WorldView and GeoEye satellite imagery from 2011. Shoreline change was then analyzed using the Digital Shoreline Analysis System (DSAS) extension for ESRI ArcGIS. Shoreline change rates decelerated to a mean rate of -0.5 m/a between the 1970s to 1990s, which was followed by a significant increase in coastal erosion to -1.3 m/a in the 1990s to 2011 time period. These observation indicate that the current rate of coastal retreat along the Yukon coast is higher than at any time before in the 60 year long observation record.

Description: Yukon’s Beaufort coast, Canada, is a highly dynamic landscape. Cultural sites, infrastructure, and travel routes used by the local population are particularly vulnerable to coastal erosion. To assess threats to these phenomena, rates of shoreline change for a 210 km length of the coast were analyzed and combined with socioeconomic and cultural information. Rates of shoreline change were derived from aerial and satellite imagery from the 1950s, 1970s, 1990s, and 2011. Using these data, conservative (S1) and dynamic (S2) shoreline projections were constructed to predict shoreline positions for the year 2100. The locations of cultural features in the archives of a Parks Canada database, the Yukon Archaeological Program, and as reported in other literature were combined with projected shoreline position changes. Between 2011 and 2100, approximately 850 ha (S1) and 2660 ha (S2) may erode, resulting in a loss of 45% (S1) to 61% (S2) of all cultural features by 2100. The last large, actively used camp area and two nearshore landing strips will likely be threatened by future coastal processes. Future coastal erosion and sedimentation processes are expected to increasingly threaten cultural sites and influence travelling and living along the Yukon coast.

Description: Permafrost coasts make up roughly one third of all coasts worldwide. Their erosion leads to the release of previously locked organic carbon, changes in ecosystems and the destruction of cultural heritage, infrastructure and whole communities. Since rapid environmental changes lead to an intensification of Arctic coastal dynamics, it is of great importance to adequately quantify current and future coastal changes. However, the remoteness of the Arctic and scarcity of data limit our understanding of coastal dynamics at a pan-Arctic scale and prohibit us from getting a complete picture of the diversity of impacts on the human and natural environment. In a joint effort of the EU project NUNATARYUK and the NSF project PerCS-Net, we seek to close this knowledge gap by collecting and analyzing all accessible high-resolution shoreline position data for the Arctic coastline. These datasets include geographical coordinates combined with coastal positions derived from archived data, surveying data, air and space born remote sensing products, or LiDAR products. The compilation of this unique dataset will enable us to reach unprecedented data coverage and will allow us a first insight into the magnitude and trends of shoreline changes on a pan-Arctic scale with locally highly resolved temporal and spatial changes in shoreline dynamics. By comparing consistently derived shoreline change data from all over the Arctic we expect that the trajectory of coastal change in the Arctic becomes evident. A synthesis of some initial results will be presented in the 2020 Arctic Report Card on Arctic Coastal Dynamics. This initiative is an ongoing effort – new data contributions are welcome!

Description: It is accepted that the Arctic is warming, and may continue to warm, but the impacts on its coasts are not well documented. Permafrost coasts make up one third of the world’s coasts, though few studies quantify recent changes. Remote sensing allows the detection of patterns in regional coastal dynamics, and provides a quantitative evidence of average coastal change and trends in rates on decadal scales. We investigated a 230 km long coastal stretch along the ice-rich and thus erosion-sensitive Yukon coast in north-western Canada over the time period from 1951 to 2015. Georeferenced aerial photographs from the 1950’s, 1970’s and 1990’s as well as World View and GeoEye satellite imagery from 2011 were used to extract shoreline positions which were analyzed using the Digital Shoreline Analysis System (DSAS) extension for ESRI ArcGIS. To provide better temporal resolution of the shore dynamics over the last 20 years (1996-2015), seven coastal monitoring sites maintained by the Geological Survey of Canada were re-surveyed using real-time kinematic differential GPS. Remote sensing data analyses show that coastal retreat accelerated substantially between the 1990s to 2010s, to an average erosion rate of 1.3 m/a. In contrast, the temporally higher resolution ground survey data indicate that coastal erosion rates among the monitoring sites were stable or even showed a decelerating trend over the last 20 years. However, within the last three years, coastal retreat at three sites increased at an unprecedented rate, locally up to 9 m/a. Ground surveys and observations, with remote sensing data, indicate that the current rate of coastal retreat along the Yukon Coast is higher than at any recorded time.

Description: The Arctic is warming. This results in longer open-water periods during which waves can interact with the shore, and extends the duration in which the land and the sea are exposed to positive temperatures. Increasing active layer depths compound the effectiveness of wave action on the coast that is often composed of ice-bound and fine-grained sediments. As permafrost soils contain approximately twice as much carbon as is currently circulating in our atmosphere, the Arctic is one of the key areas requiring study to better understand global climate change processes. Due to the fact that Arctic permafrost coasts make up one third of the World’s coasts, their dynamics are of particular interest. We investigated spatio-temporal shoreline dynamics of the Yukon Coast, characterized by very ice-rich soils and a variety of coastal landforms. Over one hundred aerial photographs from the 1950’s, the 1970’s, and the 1990’s were georeferenced on the base of GeoEye and WorldView satellite imageries from 2011. By digitizing the shoreline for each time step and performing analyses using the Esri ArcGIS extension DSAS (Digital shoreline analysis system), we classified regions according to their rate and variability of coastal erosion. Some regions are very dynamic, showing phases of fast acceleration and deceleration of coastal retreat, others appear to be very stable with little change through time. Such regions may be directly adjacent. By coupling these spatial coastal dynamics data with LiDAR (Light Detection And Ranging) data from 2012 and 2013, we calculated the volumetric erosion along the Yukon coast. Additionally, we investigated infrared theodolite and real time kinematic GPS measurements from eight coastal monitoring sites maintained by the Geological Survey of Canada, covering the last 20 years. Together, these data allow us to measure coastal evolution over the last 60 years. The temporally better resolved ground survey data indicates that coastal erosion rates, in general, show a decelerating trend over the last 20 years. However, within the last three years rates of coastal erosion along some sites (e.g. the Yukon-Alaskan Border and Stokes Point West) are increasing at unprecedented rates up to 18 m/a. These first results will help to quantify the amount of carbon released by coastal erosion along the Yukon coast and identify the contribution of coastal processes operating along the Yukon coast to regional and global nutrient cycles.

Description: Approximately twice as much carbon is stored in permafrost (perennially frozen ground) as is in the Earth’s atmosphere. Globally, nearly one third of all coasts are affected by permafrost processes. Erosion of these coasts causes re-mobilization of the stored carbon which then becomes available for the conversion into greenhouse gasses, such as methane and carbon dioxide. The Yukon Coastal Plain in the western Canadian Arctic is typically composed of ice-rich and unconsolidated sediments, including massive ice bodies for example in the form of ice wedges and segregated ice. This composition and morphology make it highly susceptible to erosion. Recent changes in environmental conditions such as record low summer sea ice extents in the years of 2007 and 2012, and rising sea- and ground temperatures, suggest an increase in coastal retreat and thus an increase in the re-mobilization of carbon. We present the initial results of a regional study focused on the spatial and temporal changes of coastal retreat along a 200 km coastal stretch of the Yukon Coastal Plain, reaching from the USA-Canada border to Shingle Point. Aerial photography from 1951 to 1996, as well as SPOT and GeoEye satellite imagery from the years of 2009 and 2011, form the basis for GIS analyses using the Digital Shoreline Analysis System (DSAS). The results are supplemented by ground observations at seven coastal monitoring sites maintained by the Geological Survey of Canada. Infrared theodolite and real time kinematic global positioning system data, together with LiDAR (Light Detection And Ranging) data from 2012 and 2013, allow us to estimate the total volumetric land loss along the Yukon coast that occurred over the last 60 years. The temporal and spatial variability in coastal erosion shows that erosion occurs at rates up to 10 m/a around Stokes Point. Western study sites show much lower erosion rates of less than 2 m/a which appear to more adequately represent the overall erosional trend of the coast. The acceleration or deceleration of coastal retreat is highly dependent on the specific location, and varies from west to east. As the overall erosional behavior of the coast is very diverse, no clear response of the coast to changing environmental conditions can be distinguished yet. Further field investigations are planned, to gain a better understanding of how the Yukon coast is responding to environmental changes.

Description: Due to its fine grained and very ice-rich sediments, the coast of the Yukon Coastal Plain forms a very dynamic landscape. Changing climatic conditions add to this by lengthening open water periods and increasing permafrost temperature, which contributes to an increase of coastal erosion. Even though the Yukon Territory has no permanent settlements along its Beaufort coast, this region is of exceptional value as it serves as a calving area for the Porcupine Caribou Herd and it comprises numerous archaeological sites which are rare remains of the rich human history of this region. The importance of this area is underpinned by the fact that about two third of the coast of the Yukon Territory is protected as part of the Ivvavik National Park, which in turn is a candidate for the UNESCO world heritage site status. Additionally, recurring plans to develop oil and gas-related infrastructure would dramatically change the nature of the coastal environment. Yet, no up-to-date information is available on the erosion of this long coastal stretch, which is detrimental to both environmental and industrial planning in the area. Here, we present initial results of an assessment of shoreline dynamics and their influence on the coastal system in the Ivvavik National Park area. We first quantified shoreline changes of the approximately 150 km long coast by means of remote sensing data. We geocoded aerial photographs from the 1950s, the 1970s and the 1990s to a GeoEye scene from 2011 and digitized the respective shorelines. We then analyzed spatial and temporal shoreline dynamics by using the Esri ArcGIS extension DSAS (Digital Shoreline Analysis System). Then, we coupled these results with a large range of ecological and cultural datasets, including ecological units, freshwater habitat extents and archaeological site positions, in order to determine the vulnerability of the coastal environment of the Ivvavik National Park. Our initial results show that coastal erosion is prevailing along most parts of the coast and only very limited coastal stretches experience accumulation. The analyses allow us to draw initial conclusions about which habitats are most affected by arctic coastal changes and which archaeological sites are prone to get lost in the near future.

Description: The Yukon coast has a vivid history reaching back to the pre-historic time of the Thule Inuit. It also archives the diverse story of the Inuvialuit and their traditional and modern lifestyle, and the influences of western cultures. These cultural sites, as well as infrastructure and boating routes, which are nowadays used by the local population, are particularly vulnerable to coastal erosion. To assess this threat, shoreline change dynamics were analyzed along a 210 km long stretch of the Yukon coast by means of geo-coded aerial imagery from the 1950s, 1970s and 1990s, as well as Geo Eye 1 and World View 2 satellite images from 2011. The calculated rates of shoreline change were used to create a conservative (S1) and a dynamic (S2) scenario for possible shoreline positions for the year 2100. The future shoreline positions were then compared to locations of cultural features obtained from a Parks Canada database, the Yukon Archaeological Program and derived from existing literature, as well as from aerial photographs and videos. In total 168 features were mapped, 26 % have been already lost due to coastal erosion and further 20 % (S1) to 26 % (S2) are expected to get lost due to future shoreline retreat, summing up to a total of 46 % (S1) to 52 % (S2) of lost cultural features by 2100. Under both scenarios, the sparse infrastructure in the form of two landing strips will be severely damaged by 2100, considerably restricting its usage. Expected higher sedimentation rates will likely lead to increasing difficulties in navigating the Workboat Passage, which is an important boating route for local travelers. Thus, expected future coastal erosion and sedimentation processes will lead to the disappearance of various cultural sites and impede travelling along the Yukon coast.