Fifty years of coastal erosion and retrogressive thaw slump activity on Herschel Island, southern Beaufort Sea, Yukon Territory, Canada

Geomorphology ◽  
2008 ◽  
Vol 95 (1-2) ◽  
pp. 84-102 ◽  
Author(s):  
H. Lantuit ◽  
W.H. Pollard
Keyword(s):  
Coastal Erosion ◽  
Beaufort Sea ◽  
Yukon Territory ◽  
Retrogressive Thaw Slump

scholarly journals Temporal stereophotogrammetric analysis of retrogressive thaw slumps on Herschel Island, Yukon Territory

2005 ◽  
Vol 5 (3) ◽  
pp. 413-423 ◽  
Author(s):  
H. Lantuit ◽  
W. H. Pollard
Keyword(s):  
Coastal Erosion ◽  
Three Dimensional ◽  
Canadian Arctic ◽  
Temporal Analysis ◽  
Yukon Territory ◽  
The Arctic ◽  
Ground Ice ◽  
Thawing Permafrost ◽  
Retrogressive Thaw Slump ◽  
Using Data

Abstract. The western Canadian Arctic is identified as an area of potentially significant global warming. Thawing permafrost, sea level rise, changing sea ice conditions and increased wave activity will result in accelerated rates of coastal erosion and thermokarst activity in areas of ice-rich permafrost. The Yukon Coastal Plain is widely recognized as one of the most ice-rich and thaw-sensitive areas in the Canadian Arctic. In particular, Herschel Island displays extensive coastal thermokarst. Retrogressive thaw slumps are a common thermokarst landform along the Herschel Island coast that have been increasing in both frequency and extent have in recent years due to increased thawing of massive ground ice and coastal erosion. The volume of sediment and ground ice eroded by retrogressive slump activity and the potential release of climate change related materials like organic carbon, carbon dioxide and methane are largely unknown. The remote setting of Herschel Island, and the Arctic in general, make direct observation of this type of erosion and the analysis of potential climate feedbacks extremely problematic. Remote sensing provides possibly the best solution to this problem. This study looks at two retrogressive thaw slumps located on the western shore of Herschel Island and using stereophotogrammetric methods attempts to (1) develop the first three-dimensional geomorphic analysis of this type of landform, and (2) provide an estimation of the volume of sediment/ground ice eroded through back wasting thermokarst activity. Digital Elevation Models were extracted for the years 1952, 1970 and 2004 and validated using data collected in the field using Kinematic Differential Global Positioning System. Estimates of sediment volumes eroded from retrogressive thaw slumps were found to vary greatly. In one case the total volume of material lost for the 1970–2004 period was approximately 1560000m3. The estimated volume of sediment alone was 360000m3. The temporal analysis of the DEMs suggest that second generation retrogressive thaw slump activity within the floor of a large polycyclic retrogressive thaw slump is possible.

scholarly journals Thermal behaviour of retrogressive thaw slumps over time revealed by ERT - an example from Herschel Island, Canada

2020 ◽  
Author(s):  
Saskia Eppinger ◽  
Michael Krautblatter ◽  
Hugues Lantuit ◽  
Michael Fritz
Keyword(s):  
Electrical Resistivity ◽  
Temperature Distribution ◽  
Thermal Behaviour ◽  
Coastal Erosion ◽  
Yukon Territory ◽  
Thermal Processes ◽  
Temperature Changes ◽  
Arctic Regions ◽  
Retrogressive Thaw Slump ◽  
Over Time

<p>In the last century the number of retrogressive thaw slumps has doubled in some arctic regions, e.g. Herschel Island, Yukon Territory, Canada [Lantuit and Pollard, 2008]. Retrogressive thaw slumps are a common thermocarst landform along the coast of Herschel Island [Lantuit and Pollard, 2005]. However mechanical conditions leading to the evolution of those retrogressive thaw slumps are poorly understood.</p><p>For a better understanding of internal thermal processes in these retrogressive thaw slumps we implemented different electrical resistivity profiles (ERT). They cross the focused thaw slump longitudinally and transversally. We compared about 2 km of new ERT-data from 2019 with the same transects from 2011 to gain information about the temperature distribution and the temperature changes in the slump ground.</p><p>The aim for our study is to gain a profound understanding of the strong and deep thermal disturbances generated by retrogressive thaw slumps and how they change over time, leading to a possible polycyclicality of these slumps.</p><p> </p><p> </p><p> </p><p> </p><p>Lantuit, H., and W. H. Pollard (2005), Temporal stereophotogrammetric analysis of retrogressive thaw slumps on Herschel Island, Yukon Territory, <em>Nat. Hazards Earth Syst. Sci. 5 </em>(3), 413–423.</p><p>Lantuit, H., and W. H. Pollard (2008), Fifty years of coastal erosion and retrogressive thaw slump activity on Herschel Island, southern Beaufort Sea, Yukon Territory, Canada, <em>Geomorphology 95 </em>(1-2), 84–102.</p>

scholarly journals Rapid retreat of permafrost coastline observed with aerial drone photogrammetry

2019 ◽  
Vol 13 (5) ◽  
pp. 1513-1528 ◽  
Author(s):  
Andrew M. Cunliffe ◽  
George Tanski ◽  
Boris Radosavljevic ◽  
William F. Palmer ◽  
Torsten Sachs ◽  
...  
Keyword(s):  
Coastal Erosion ◽  
Average Rate ◽  
Temporal Frequency ◽  
Shoreline Change ◽  
Yukon Territory ◽  
Aerial Photographs ◽  
The Arctic ◽  
Storm Events ◽  
Short Term

Abstract. Permafrost landscapes are changing around the Arctic in response to climate warming, with coastal erosion being one of the most prominent and hazardous features. Using drone platforms, satellite images, and historic aerial photographs, we observed the rapid retreat of a permafrost coastline on Qikiqtaruk – Herschel Island, Yukon Territory, in the Canadian Beaufort Sea. This coastline is adjacent to a gravel spit accommodating several culturally significant sites and is the logistical base for the Qikiqtaruk – Herschel Island Territorial Park operations. In this study we sought to (i) assess short-term coastal erosion dynamics over fine temporal resolution, (ii) evaluate short-term shoreline change in the context of long-term observations, and (iii) demonstrate the potential of low-cost lightweight unmanned aerial vehicles (“drones”) to inform coastline studies and management decisions. We resurveyed a 500 m permafrost coastal reach at high temporal frequency (seven surveys over 40 d in 2017). Intra-seasonal shoreline changes were related to meteorological and oceanographic variables to understand controls on intra-seasonal erosion patterns. To put our short-term observations into historical context, we combined our analysis of shoreline positions in 2016 and 2017 with historical observations from 1952, 1970, 2000, and 2011. In just the summer of 2017, we observed coastal retreat of 14.5 m, more than 6 times faster than the long-term average rate of 2.2±0.1 m a−1 (1952–2017). Coastline retreat rates exceeded 1.0±0.1 m d−1 over a single 4 d period. Over 40 d, we estimated removal of ca. 0.96 m3 m−1 d−1. These findings highlight the episodic nature of shoreline change and the important role of storm events, which are poorly understood along permafrost coastlines. We found drone surveys combined with image-based modelling yield fine spatial resolution and accurately geolocated observations that are highly suitable to observe intra-seasonal erosion dynamics in rapidly changing Arctic landscapes.

Modern and Late Holocene Retrogressive Thaw Slump Activity on the Yukon Coastal Plain and Herschel Island, Yukon Territory, Canada

2012 ◽  
Vol 23 (1) ◽  
pp. 39-51 ◽  
Author(s):  
H. Lantuit ◽  
W. H. Pollard ◽  
N. Couture ◽  
M. Fritz ◽  
L. Schirrmeister ◽  
...  
Keyword(s):  
Coastal Plain ◽  
Late Holocene ◽  
Yukon Territory ◽  
Retrogressive Thaw Slump

The thermal regime of a retrogressive thaw slump near Mayo, Yukon Territory

2000 ◽  
Vol 37 (7) ◽  
pp. 967-981 ◽  
Author(s):  
C R Burn
Keyword(s):  
Dominant Mode ◽  
Yukon Territory ◽  
Permafrost Degradation ◽  
Near Surface ◽  
Ground Temperatures ◽  
Fine Grained ◽  
Data Loggers ◽  
Development Data ◽  
Retrogressive Thaw Slump ◽  
Frost Penetration

The development of a retrogressive thaw slump near Mayo, Yukon Territory, has been traced from initiation by bank erosion (~1949) of the Stewart River to stabilization in 1993-1994. The stabilized headwall of the slump is 450 m from the river, and the slope of the slump floor is 3°. A transect of the slump from the river to the stabilized headwall was drilled in July 1995, to determine the extent and rate of permafrost degradation in the slump floor. Thermistors were placed in access tubes to 12 m depth at five sites, four near the transect and one in undisturbed terrain, to determine the magnitude of thermal disturbance due to slump development. Data loggers at the sites recorded the ground temperature at 1 m depth for two years from August 1995. The annual mean ground temperatures measured by the data loggers varied between 1.2° and 1.8°C in the slump, compared with -2.4°C in undisturbed ground, indicating a disturbance of about 4°C due to slumping. The depth of thaw in the slump floor is consistent with the Stefan solution for thawing of permafrost. Conduction is the dominant mode of heat transfer in the slump, where the soil is fine grained and there is almost no organic horizon. Winter ground temperatures at 1 m depth were nearly 6°C warmer in the slump than in the surrounding forest, even though snow depths were similar, due to the release of latent heat during prolonged frost penetration. These data demonstrate the importance of subsurface conditions on near-surface ground temperatures in winter.

scholarly journals Geochemistry of Coastal Permafrost and Erosion-Driven Organic Matter Fluxes to the Beaufort Sea Near Drew Point, Alaska

2021 ◽  
Vol 8 ◽  
Author(s):  
Emily M. Bristol ◽  
Craig T. Connolly ◽  
Thomas D. Lorenson ◽  
Bruce M. Richmond ◽  
Anastasia G. Ilgen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Late Pleistocene ◽  
21St Century ◽  
Marine Sediments ◽  
Coastal Erosion ◽  
Beaufort Sea ◽  
The Arctic ◽  
The Holocene ◽  
Kuparuk River

Accelerating erosion of the Alaska Beaufort Sea coast is increasing inputs of organic matter from land to the Arctic Ocean, and improved estimates of organic matter stocks in eroding coastal permafrost are needed to assess their mobilization rates under contemporary conditions. We collected three permafrost cores (4.5–7.5 m long) along a geomorphic gradient near Drew Point, Alaska, where recent erosion rates average 17.2 m year−1. Down-core patterns indicate that organic-rich soils and lacustrine sediments (12–45% total organic carbon; TOC) in the active layer and upper permafrost accumulated during the Holocene. Deeper permafrost (below 3 m elevation) mainly consists of Late Pleistocene marine sediments with lower organic matter content (∼1% TOC), lower C:N ratios, and higher δ13C values. Radiocarbon-based estimates of organic carbon accumulation rates were 11.3 ± 3.6 g TOC m−2 year−1 during the Holocene and 0.5 ± 0.1 g TOC m−2 year−1 during the Late Pleistocene (12–38 kyr BP). Within relict marine sediments, porewater salinities increased with depth. Elevated salinity near sea level (∼20–37 in thawed samples) inhibited freezing despite year-round temperatures below 0°C. We used organic matter stock estimates from the cores in combination with remote sensing time-series data to estimate carbon fluxes for a 9 km stretch of coastline near Drew Point. Erosional fluxes of TOC averaged 1,369 kg C m−1 year−1 during the 21st century (2002–2018), nearly doubling the average flux of the previous half-century (1955–2002). Our estimate of the 21st century erosional TOC flux year−1 from this 9 km coastline (12,318 metric tons C year−1) is similar to the annual TOC flux from the Kuparuk River, which drains a 8,107 km2 area east of Drew Point and ranks as the third largest river on the North Slope of Alaska. Total nitrogen fluxes via coastal erosion at Drew Point were also quantified, and were similar to those from the Kuparuk River. This study emphasizes that coastal erosion represents a significant pathway for carbon and nitrogen trapped in permafrost to enter modern biogeochemical cycles, where it may fuel food webs and greenhouse gas emissions in the marine environment.

Recent mollusc distribution patterns and palaeobathymetry, southeastern Beaufort Sea

1977 ◽  
Vol 14 (9) ◽  
pp. 2013-2028 ◽  
Author(s):  
Frances J. E. Wagner
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Distribution Patterns ◽  
Beaufort Sea ◽  
Yukon Territory ◽  
Sea Levels ◽  
Near Shore ◽  
Depth Ranges ◽  
Offshore Transport ◽  
Shallow Water Species

Molluscs were obtained from 515 of the 657 grab samples collected 1970–1972 inclusive from southeastern Beaufort Sea, from 29 of the 46 cores taken in the area, and from raised marine deposits at Kay Point and on Herschel Island, Yukon Territory. One hundred and one species have been identified. Water depth was apparently the major factor controlling species distribution. Holocene sea levels, determined by comparing core faunas with the established depth ranges for living specimens, are considered to be reasonably accurate for near-shore sites, but yield excessively shallow water depth figures for deep stations (outer shelf and slope). The anomalous results are probably related to offshore transport of shallow water species.

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