Distribution and origin of ground ice in University Valley, McMurdo Dry Valleys, Antarctica

2016 ◽  
Vol 29 (2) ◽  
pp. 183-198 ◽  
Author(s):  
Caitlin Lapalme ◽  
Denis Lacelle ◽  
Wayne Pollard ◽  
David Fisher ◽  
Alfonso Davila ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Ground Surface ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Ground Ice ◽  
Permafrost Soils ◽  
Glacier Ice ◽  
Ice Conditions ◽  
Ice Content ◽  
Moisture Conditions

AbstractGround ice is one of the most important and dynamic geologic components of permafrost; however, few studies have investigated the distribution and origin of ground ice in the McMurdo Dry Valleys of Antarctica. In this study, ice-bearing permafrost cores were collected from 18 sites in University Valley, a small hanging glacial valley in the Quartermain Mountains. Ground ice was found to be ubiquitous in the upper 2 m of permafrost soils, with excess ice contents reaching 93%, but ground ice conditions were not homogeneous. Ground ice content was variable within polygons and along the valley floor, decreasing in the centres of polygons and increasing in the shoulders of polygons towards the mouth of the valley. Ground ice also had different origins: vapour deposition, freezing of partially evaporated snow meltwater and buried glacier ice. The variability in the distribution and origin of ground ice can be attributed to ground surface temperature and moisture conditions, which separate the valley into distinct zones. Ground ice of vapour-deposition origin was predominantly situated in perennially cryotic zones, whereas ground ice formed by the freezing of evaporated snow meltwater was predominantly found in seasonally non-cryotic zones.

Relict basal ice from the Laurentide Ice Sheet near Lac de Gras, Slave Geological Province, N.W.T., Canada

2021 ◽  
Author(s):  
Stephan Gruber ◽  
Rupesh Subedi ◽  
Steven V. Kokelj
Keyword(s):  
Ice Sheets ◽  
Ice Sheet ◽  
Basic Research ◽  
Laurentide Ice Sheet ◽  
Infrastructure Development ◽  
Ground Ice ◽  
Basal Ice ◽  
Soils And Sediments ◽  
Permafrost Soils ◽  
Ice Content

<p>A 2015 drilling campaign near Lac de Gras has recovered permafrost core interpreted to contain preserved basal ice of the Laurentide Ice Sheet (Subedi et al., 2020). Previous samples of basal ice from ice sheets originate from coring, usually beneath modern ice divides, modern margins of Arctic icecaps that have preserved basal ice-sheet ice, or from studies near the margins of former ice sheets. The present study may be the first evidence of basal ice a few hundred kilometers from ice divides. In this intermediate zone, rates of erosion beneath an ice sheet increase and the thermal regime at the base varies. Our finding is of applied relevance because it highlights the mosaic character of a landscape that contains terrain types with non-negligible ground-ice content, poised for climate-driven thaw and landscape change. The occurrence and mosaic character of preserved ice may be reconciled with glaciological theory and observations from mineral prospecting using the theory on the genesis of dispersal plumes in till developed by Hooke et al. (2013). The existence of preserved basal ice opens basic-research opportunities alongside exploration, mining and infrastructure development in the area.  </p><p>Hooke, R. L. B., Cummings, D. I., Lesemann, J. E., and Sharpe, D. R.: Genesis of dispersal plumes in till, Can. Jo. Earth Sci., 50, 847–855, https://doi.org/10.1139/cjes-2013-0018, 2013.</p><p>Subedi, R., Kokelj, S. V., and Gruber, S.: Ground ice, organic carbon and soluble cations in tundra permafrost soils and sediments near a Laurentide ice divide in the Slave Geological Province, Northwest Territories, Canada, The Cryosphere, 14, 4341–4364, https://doi.org/10.5194/tc-14-4341-2020, 2020.</p>

Snow recurrence sets the depth of dry permafrost at high elevations in the McMurdo Dry Valleys of Antarctica

2008 ◽  
Vol 21 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Christopher P. McKay
Keyword(s):  
Theoretical Analysis ◽  
Mcmurdo Dry Valleys ◽  
Field Observations ◽  
Dry Valleys ◽  
Ground Ice ◽  
Recurrence Intervals ◽  
High Elevations ◽  
The Antarctic

AbstractDry permafrost on Earth is unique to the Antarctic and is found in the upper elevations of the McMurdo Dry Valleys. Despite its widespread presence in the Dry Valleys, the factors that control the distribution of dry permafrost and the ice-cemented ground below it are poorly understood. Here I show, by a combination of theoretical analysis and field observations, that the recurrence of snow can explain the depth of dry permafrost and the location of ice-cemented ground in Antarctica. For data from Linnaeus Terrace at 1600–1650 m elevation in Upper Wright Valley a recurrence intervals of about two years explains the presence of ground ice at 25 cm depth, under 12.5 cm of dry permafrost. Snow recurrence periods longer than 10 years would create only dry permafrost at this site. The snow gradient in University Valley resulting from the windblown snow from the polar plateau creates a corresponding gradient in the depth to ice-cemented ground. On the floor of Beacon Valley, the presence of dry permafrost without underlying ice-cemented ground indicates snow recurrence intervals of more than 10 years and implies that the ancient massive ice in this valley is not stable. Snow recurrence may also set the depth to ground ice on Mars.

Surficial materials and related ground ice conditions, Slave Province, N.W.T., Canada

1999 ◽  
Vol 36 (7) ◽  
pp. 1227-1238 ◽  
Author(s):  
Lynda A Dredge ◽  
Daniel E Kerr ◽  
Stephen A Wolfe
Keyword(s):  
Gulf Coast ◽  
Regional Scale ◽  
Coarse Grained ◽  
Silty Clay ◽  
Ground Ice ◽  
Wide Range ◽  
Ice Conditions ◽  
Western Arctic ◽  
Climatic History ◽  
Ice Content

Surficial mapping and geologic information on the nature and evolution of surficial materials in the Slave geologic province indicate that the geotechnical properties and potential ground ice contents associated with these materials depend largely upon their provenance, depositional conditions, and the postglacial climatic history. This information may be used to provide a regional-scale view of the distribution of ground ice conditions and terrain sensitivities associated with various surficial materials. In till veneers and blankets, ground ice content is generally low, as suggested by lack of thermokarst and other permafrost features. However, distinctive surface relief in hummocky till including kettle depressions, rim-ridges, and shallow thaw flowslides may be attributed to massive ice, resulting in sensitive till terrain. Although many outwash sediments have low ice contents near the surface, massive ice ranging from 5 to 10 m thick is present in some eskers and ice-contact outwash sediments. These are associated with thermokarst, slope movement, and collapse features, indicative of meltout or creep of large bodies of massive ice. The terrain sensitivity associated with these deposits is typically low to moderate, due to the coarse-grained nature of the sediments. In contrast, terrain sensitivity is high, and active-layer detachment slides are common along the Coronation Gulf coast where frozen silty clay marine sediments contain a wide range of ice contents. Results from this study may be applied to a much more extensive area of the glaciated western Arctic mainland and adjacent Arctic coastal plain in which materials with a similar glacial history are found.

scholarly journals Reconstructing 15 Myr of environmental change in the McMurdo Dry Valleys through permafrost geochemistry

2021 ◽  
Author(s):  
Marjolaine Verret
Keyword(s):  
Active Layer ◽  
Arid Environment ◽  
Trophic Levels ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Ground Ice ◽  
Paleoenvironmental Changes ◽  
Table Mountain ◽  
Continental Antarctica ◽  
High Elevations

<p><b>The McMurdo Dry Valleys of Antarctica are the largest ice-free region in Antarctica. Valley downcutting by major outlet glaciers and post-glacial uplift since the mid-Miocene have resulted in predominantly younger surficial sediments in the low elevation, coastal areas and significantly older sediments in high elevation, inland areas. The hyper-arid conditions that prevail in the high elevations (> 1000 m a.s.l.) of the McMurdo Dry Valleys have protected these surfaces from alteration and weathering, and provide important sediment records of paleoenvironments dating back to the early Miocene. The Friis Hills (77°45’S, 161°30’E, 1200–1500 m a.s.l.) are a 12 km-wide inselberg situated at the head of Taylor Valley. This unique location allowed Miocene-age sediments to be preserved and protected from subsequent ice sheet expansions. Permafrost within these sediments is potentially the oldest on Earth. </b></p><p>As sediments accumulate in periglacial environments, permafrost aggrades with minimal lag time and potentially preserves sediments, organic material and ground ice. The 2016 Friis Hills Drilling Project retrieved a ∼50 m thick permafrost sequence, which not only consists of an archive of Antarctic environmental changes from approximately 14–15 Ma but also records the paleoenvironmental changes of the Neogene and provides insight on the modern hyper-arid environment. The main objective of this project is to understand the unique geochemical characteristics of these permafrost cores and document 15 Myr of change in the upper elevations of the McMurdo Dry Valleys. </p><p>Paleoenvironmental reconstructions of interglacial periods suggest a tundra-like environment in the high elevations of continental Antarctica through the mid-Miocene. Plants such as lichens, liverworts, mosses, grasses and sedges, dicots and Nothofagaceae occupied the Friis Hills during the mid-Miocene. The δ13C signal of C3 plants (-25.5 ± 0.7 ‰ VPDB) corresponds to a semi-arid environment with a mean annual precipitation ranging from 300 to 850 mm yr-1. The unusually high δ15N reflects an ecosystem with up to three trophic levels, supported by the presence of insect fragments, feathers barbs (birds) and tardigrades fragments within the sediment. The deep ice lenses and their meteoric signature suggest a near-saturated active layer during the mid-Miocene. Temperature reconstructions based on the corrected δ18O value of the deep ground ice and change in paleogeography imply that the mid-Miocene (11.1–13.9 Ma) was ∼6 to 12°C warmer. These paleoenvironmental conditions are comparable to those found in the modern Arctic, such as in west Greenland. </p><p>A dominant trend of literature suggests that the high elevations of the McMurdo Dry Valleys have remained under a hyper-arid polar climate since ∼13.8 Ma. However, the presence of 10Bemet in the upper section of the Friis Hills and Table Mountain cores provides evidence for the translocation of clays, which is only possible under a warmer and wetter climate. The 10Bemet concentrations imply that these conditions were present until ∼6.0 Ma at Friis Hills and Table Mountain, consequently challenging the idea that the upper McMurdo Dry Valleys have remained frozen under hyper-arid climate since the mid-Miocene climate transition. Hence, this finding supports the hypothesis that the Miocene has undergone progressive cooling with onset of polar aridity between 7 and 5.4 Ma. The erosion-corrected paleo-active layer depth suggests mean annual air temperatures ranging from -12 to -9°C ∼6.0 Ma. In other words, this thesis shows that the upper McMurdo Dry Valleys have been frozen under hyperarid conditions only since ∼6 Ma and not for 14 Myr as previously thought. </p><p>The ground ice in the uppermost 1 m originates from the modern freezing of evaporated snowmelt and the presence of high salt content which allows unfrozen water in the near-surface. The conformity of dry permafrost samples to biological ratios suggests that the modern environment is regulated by biochemical processes and the current pool of organic carbon in the dry permafrost appears to be in equilibrium with a modern climate and ecosystem. These findings not only characterize the paleoenvironmental changes of continental Antarctica through the late Miocene but also provide a better understanding of the modern ultraxerous conditions of the McMurdo Dry Valleys.</p>

scholarly journals Hyperspectral measurements of wet, dry and saline soils from the McMurdo Dry Valleys: soil moisture properties from remote sensing

2014 ◽  
Vol 26 (5) ◽  
pp. 565-572 ◽  
Author(s):  
Joseph Levy ◽  
Anne Nolin ◽  
Andrew Fountain ◽  
James Head
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Thermal State ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Non Invasive ◽  
High Concentrations ◽  
Remote Sensing Techniques ◽  
Moisture Conditions ◽  
Chloride Salts

AbstractSoil moisture is a spatially heterogeneous quantity in the McMurdo Dry Valleys of Antarctica that exerts a large influence on the biological community and on the thermal state of Dry Valleys permafrost. The goal of this project was to determine whether hyperspectral remote sensing techniques could be used to determine soil moisture conditions in the Dry Valleys. We measured the spectral reflectance factors of wetted soil samples from the Dry Valleys under natural light conditions and related diagnostic spectral features to surface layer soil moisture content. Diagnostic water absorption features in the spectra at 1.4 µm and 1.9 µm were present in all samples, including samples doped with high concentrations of chloride salts. The depth of the 1.4 µm absorption is shown to increase linearly with increasing gravimetric water content. These results suggest that airborne hyperspectral imaging of the Dry Valleys could generate soil moisture maps of this environment over large spatial areas using non-invasive remote-sensing techniques.

Shallow seismic surveys and ice thickness estimates of the Mullins Valley debris-covered glacier, McMurdo Dry Valleys, Antarctica

2007 ◽  
Vol 19 (4) ◽  
pp. 485-496 ◽  
Author(s):  
David E. Shean ◽  
James W. Head ◽  
David R. Marchant
Keyword(s):  
Mcmurdo Dry Valleys ◽  
P Wave ◽  
Ice Thickness ◽  
Dry Valleys ◽  
Near Surface ◽  
Seismic Surveys ◽  
Shallow Seismic ◽  
Ice Accumulation ◽  
Active Portion ◽  
Glacier Ice

AbstractSeveral debris-covered glaciers occupy tributaries of upper Beacon Valley, Antarctica. Understanding their flow dynamics and ice thickness is important for palaeoclimate studies and for understanding the origins of ancient ice elsewhere in the McMurdo Dry Valleys region. We present the results of several shallow seismic surveys in Mullins Valley, where the largest of these debris-covered glaciers is located. Our results suggest that beneath a thin sublimation till and near-surface horizon of dirty glacier ice, lies relatively pure glacier ice (P-wave velocity ~3700–3800 m s-1), with total thickness estimates of ~90–95 m towards the valley head, and ~40–65 m near the entrance to Beacon Valley, ~2.5 km downglacier. P-wave velocities decrease downvalley, suggesting that the material properties of the ice change with increasing distance from the ice-accumulation zone. These new data are used to calibrate an ice thickness profile for the active portion of the Mullins Valley debris-covered glacier (upper ~3.5 km) and to shed light on the origin and spatial distribution of enclosed debris.

scholarly journals Numerical Assessments of Excess Ice Impacts on Permafrost and Greenhouse Gases in a Siberian Tundra Site Under a Warming Climate

2021 ◽  
Vol 9 ◽  
Author(s):  
Hotaek Park ◽  
Alexander N. Fedorov ◽  
Pavel Konstantinov ◽  
Tetsuya Hiyama
Keyword(s):  
Ground Surface ◽  
Climate Scenario ◽  
Permafrost Soil ◽  
Biogeochemical Model ◽  
Active Layer Thickness ◽  
Warming Climate ◽  
Permafrost Soils ◽  
Wet Condition ◽  
Ice Content ◽  
Ice Impacts

Excess ice that exists in forms such as ice lenses and wedges in permafrost soils is vulnerable to climate warming. Here, we incorporated a simple representation of excess ice in a coupled hydrological and biogeochemical model (CHANGE) to assess how excess ice affects permafrost thaw and associated hydrologic responses, and possible impacts on carbon dioxide and methane (CH4) fluxes. The model was used to simulate a moss-covered tundra site in northeastern Siberia with various vertical initializations of excess ice under a future warming climate scenario. Simulations revealed that the warming climate induced deepening of the active layer thickness (ALT) and higher vegetation productivity and heterotrophic respiration from permafrost soil. Meanwhile, excess ice temporarily constrained ALT deepening and thermally stabilized permafrost because of the highest latent heat effect obtained under these conditions. These effects were large under conditions of high excess ice content distributed in deeper soil layers, especially when covered by moss and thinner snow. Once ALT reached to the layer of excess ice, it was abruptly melted, leading to ground surface subsidence over 15–20 years. The excess ice meltwater caused deeper soil to wet and contributed to talik formation. The anaerobic wet condition was effective to high CH4 emissions. However, as the excess ice meltwater was connected to the subsurface flow, the resultant lower water table limited the CH4 efflux. These results provide insights for interactions between warming climate, permafrost excess ice, and carbon and CH4 fluxes in well-drained conditions.

Stability of massive ground ice bodies in University Valley, McMurdo Dry Valleys of Antarctica: Using stable O–H isotope as tracers of sublimation in hyper-arid regions

2011 ◽  
Vol 301 (1-2) ◽  
pp. 403-411 ◽  
Author(s):  
Denis Lacelle ◽  
Alfonso F. Davila ◽  
Wayne H. Pollard ◽  
Dale Andersen ◽  
Jennifer Heldmann ◽  
...  
Keyword(s):  
Arid Regions ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Ground Ice

scholarly journals The climate history of early Mars: insights from the Antarctic McMurdo Dry Valleys hydrologic system

2014 ◽  
Vol 26 (6) ◽  
pp. 774-800 ◽  
Author(s):  
James W. Head ◽  
David R. Marchant
Keyword(s):  
Ground Surface ◽  
Volcanic Eruptions ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Climate History ◽  
Air Temperatures ◽  
Hydrological System ◽  
Hydrologic System ◽  
Early Mars ◽  
Geologic Record

AbstractThe early climate of Mars (Noachian Period, the first ~20% of its history) is thought to differ significantly from that of its more recent history (Amazonian Period, the last ~66%) which is characterized by hyperarid, hypothermal conditions that result in mean annual air temperatures (MAAT) well below 0°C, a global cryosphere, minimal melting on the ground surface, and a horizontally stratified hydrologic system. We explore the nature of the fluvial and lacustrine environments in the Mars-like hyperarid, hypothermal McMurdo Dry Valleys (MDV), where the MAAT is well below 0°C (~ -14 to -30°C) in order to assess whether the Late Noachian geologic record can be explained by a climate characterized by “cold and icy” conditions. We find that the MDV hydrological system and cycle provide important insights into the potential configuration of a “cold and icy” early Mars climate in which MDV-like ephemeral streams and rivers, and both closed-basin and open-basin lakes could form. We review a series of MDV fluvial and lacustrine features to guide investigators in the analysis of the geomorphology of early Mars and we outline a new model for the nature and evolution of a “cold and icy” Late Noachian climate based on these observations. We conclude that a cold and icy Late Noachian Mars with MAAT below freezing, but peak seasonal and peak daily temperatures above 0°C, could plausibly account for the array of Noachian-aged fluvial and lacustrine features observed on Mars. Our assessment also provides insight into the potential effects of punctuated warming on a cold and icy early Mars, in which impact crater formation or massive volcanic eruptions cause temperatures in the melting range for decadal to centennial timescales. We outline a set of outstanding questions and tests concerning the nature and evolution of these features on Mars.

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