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2. Simulation of Influence of Special Regimes of Horizontal Flare Systems on Permafrost
- Author
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Filimonov, M. Yu., Vaganova, N. A., Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Pandu Rangan, C., Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Dimov, Ivan, editor, Faragó, István, editor, and Vulkov, Lubin, editor
- Published
- 2019
- Full Text
- View/download PDF
3. Discussion on the Preceding Papers
- Author
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Smith, J. E., Longton, R. E., Holdgate, M. W., Greene, S. W., Dunnet, G. M., Gimingham, C. H., Brown, P. D., Heal, O. W., Allen, S. E., and Tilbrook, P. J.
- Published
- 1967
4. Effects of microbial-converted ancient permafrost organic carbon on the growth and reproduction of Daphnia magna.
- Author
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Gan Y, Su Y, and Ma J
- Subjects
- Animals, Ecosystem, Daphnia, Carbon, Reproduction, Soil, Permafrost, Chlorella
- Abstract
Immense amounts of ancient (radiocarbon age over 200 years) organic carbon (OC) from permafrost are released into aquatic systems. Ancient terrestrial OC exists in numerous aquatic ecosystems. It has been reported that ancient OC can be incorporated by consumers in aquatic ecosystems, but the effect of ancient OC on the growth of consumers has rarely been studied. In this study, we extracted ancient dissolved organic carbon (DOC) from frozen soils in an alpine lake catchment. After a 6-day microbial conversion period, the contents of ω3 and ω6 polyunsaturated fatty acids (PUFAs) in ancient DOC increased. Proteobacteria and Actinobacteria were the primary taxa consuming the permafrost DOC and generating fatty acids. In addition to the exclusive diet of soil DOC (containing bacteria) or Chlorella pyrenoidosa, mixed diets of Chlorella pyrenoidosa, and ancient DOC (containing bacteria) in ratios of 2:1, 1:1, and 1:2 (by carbon concentration) were used to feed Daphnia magna. We discovered that Daphnia reared on the mixture with the DOC:Chlorella ratio of 1:2 had the highest contents of ω3 PUFAs and FAs. Daphnia reared exclusively on Chlorella and the mixture with the DOC:Chlorella ratio of 1:2 had the largest body size (3.1-3.4 mm) and the highest offspring production (95.5-96.2 ind
-1 ). Daphnia fed on mixed diets exhibited higher intrinsic rates of population growth (0.48-0.53 d-1 ) compared to those fed exclusively on Chlorella pyrenoidosa, or ancient DOC plus bacteria. Overall, ancient soil OC converted by bacteria can act as a valuable supplement to algae food to promote Daphnia growth., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2023
- Full Text
- View/download PDF
5. (Un)frozen foundations: A study of permafrost construction practices in Russia, Alaska, and Canada.
- Author
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Landers K and Streletskiy D
- Subjects
- Alaska, Ecosystem, Arctic Regions, Russia, Canada, Permafrost chemistry
- Abstract
The Arctic is rapidly warming posing a significant threat to underlying permafrost. Permafrost degradation has already resulted in extensive damage to the Arctic's built infrastructure, putting communities and industries at risk. Projected climate warming will further reduce the capacity of permafrost to support infrastructure, thereby requiring a rethinking of construction and development of permafrost regions in the future. This paper focuses on three Arctic regions with a substantial presence of population and infrastructure on permafrost: USA (Alaska), Canada, and Russia. The three regions' permafrost construction practices are examined in order to identify best practices and major gaps. We identify a lack of standardized, codified construction guidelines; an absence of permafrost-geotechnical monitoring in communities; barriers to integrating climate scenarios into future planning; limited data sharing; and low numbers of permafrost professionals as major constraints limiting the region's resilience in the face of climate change. Refining building practices and standards, implementing operational permafrost monitoring systems, developing downscaled climate projections, and integrating local knowledge will minimize the impacts of permafrost degradation under rapidly warming climatic conditions., (© 2023. The Author(s) under exclusive licence to Royal Swedish Academy of Sciences.)
- Published
- 2023
- Full Text
- View/download PDF
6. Dealing with sand in the Arctic city of Nadym.
- Author
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Kuklina V, Sizov O, Fedorov R, and Butakov D
- Subjects
- Humans, Cities, Arctic Regions, Siberia, Sand, Permafrost
- Abstract
Sand plays an important role in the Arctic urban development as construction material and stable ground. Significance of its studies increases in face of permafrost degradation and coastal erosion and for understanding human capacities to restore natural landscapes after anthropogenic disturbances. This paper examines changing human interactions with sand in the city of Nadym, northwest of Siberia. The study utilizes an interdisciplinary approach which includes remote sensing and GIS analysis, field observations, and interviews with local residents and stakeholders. Analysis of spatial and social characteristics of sand demonstrates different roles of sand as part of the landscape, a resource, and as a mediator in urban and infrastructure development. Understanding the diversity of sand qualities, its uses, and perceptions is relevant for studies of landscape disturbances, resilience, vulnerability, and adaptive capacities of Arctic cities., (© 2023. The Author(s) under exclusive licence to Royal Swedish Academy of Sciences.)
- Published
- 2023
- Full Text
- View/download PDF
7. REPLY TO A.V. SMAGIN: V. WHAT IS WRONG WITH AN 'ABIOTIC PAPER' AND DO WE ALWAYS NEED TO TAKE INTO ACCOUNT THE ABIOTIC GAS ABSORPTION BY SOIL?
- Author
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Mikhail Glagolev, A. F. Sabrekov, Glagolev Mikhail Vladimirovich, and Sabrekov Alexander Faritovich
- Subjects
Abiotic component ,Methane emissions ,chemistry.chemical_compound ,chemistry ,Soil water ,Environmental science ,Soil science ,Climate model ,Permafrost ,Absorption (electromagnetic radiation) ,Methane - Abstract
A paper of prof. A.V. Smagin [2007] is analyzed (both from outer scientometric and inner meaningful points of view). In this paper he considers the abiotic absorption of gases by organogenic soils. In this regard, claims of the author of the article to the work of V. M. Stepanenko and his colleagues on the modeling of methane emissions from lakes on the territory of permafrost are also discussed. An idea that (in contrast to the views of A.V. Smagin) a necessity to account for abiotic uptake depends on properties of modeled object is formulated. In particular, if blocks of climate models are developed (like the Stepanenko model), which should work on timescales of 103÷104 hours and more, it makes no sense to take into account the abiotic uptake that occurs within significantly shorter time intervals and concerns an extremely small amount of methane (compared to its total amount, which is released within the indicated 103-104 hours). In addition potential uncertainties of deep soil chamber technique that could be generated by abiotic absorption and biogenic oxidation of methane are discussed.
- Published
- 2019
8. Response to the discussion by Van Vliet-Lanoë et al. of the paper ‘Features caused by ground ice growth and decay in Late Pleistocene fluvial deposits, Paris Basin, France’ (Bertran et al., 2018, Geomorphology 310, 84–101)
- Author
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Kevin Manchuel, Pascal Bertran, Mark D. Bateman, Marianne Font, Eric Andrieux, Deborah Sicilia, Institut national de recherches archéologiques préventives (Inrap), De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), University of Sheffield [Sheffield], Department of Geography [Sheffield], Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU), and EDF (EDF)
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Pleistocene ,Faulting ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Fluvial ,Context (language use) ,Last Glacial permafrost ,010502 geochemistry & geophysics ,Permafrost ,01 natural sciences ,Thermokarst ,Sedimentary depositional environment ,Paleontology ,Terrace (geology) ,Paris Basin ,Thermokarst lakes ,Alluvium ,[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
(IF 3.82; Q1); International audience; The response by Van Vliet-Lanoë et al. to our paper on potential thermokarst features in Pleistocene alluvial deposits from the Paris Basin (France) presents inconsistencies that we consider here successively. These are (1) the map of the maximum extent of Pleistocene permafrost in France, (2) the genesis of liquefaction and fluidization structures in periglacial environments, (3) the origin of thermokarst lakes and recumbent folds, (4) the depositional context of sandy units, and (5) the age of the studied deposits. All structures result from the interplay between (1) the growth and degradation of ice wedges, which are responsible for the development of a mound-like topography (badland thermokarst reliefs) on the edge of the alluvial terrace and from the initiation of ponding elsewhere on the terrace, (2) the degradation of lithalsa that developed later in the lacustrine deposits. The sequence was dated confidently to the Late Weichselian.
- Published
- 2019
9. Numerical analysis for permafrost temperature field in the short term of permafrost subgrade filling
- Author
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Wang, Yunjia and Zhang, Qianli
- Published
- 2023
- Full Text
- View/download PDF
10. Papers Presented to Commemorate the Legacy to Permafrost Science of Professor J. Ross Mackay (1915-2014)
- Author
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Christopher R. Burn
- Subjects
010506 paleontology ,010504 meteorology & atmospheric sciences ,Physical geography ,Permafrost ,01 natural sciences ,Archaeology ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Published
- 2017
11. GEOMORPHOLOGICAL APPROACH TO THE RIVER RUNOFF EVALUATION IN THE GEOLOGICAL PAST (Paper 1. Regime Equations)
- Subjects
Hydrology ,Flood discharge ,Flood myth ,Environmental science ,Snow ,Permafrost ,Earth-Surface Processes - Abstract
Reconstruction of river palaeodischarges based on the morphology of modern rivers meets the following requirements to the empirical regime equations in use: 1) they should cover the broad range of environment conditions to include the ancient conditions of river formation; 2) they should be controlled by a small number of variables selected according to the needs of the problem; 3) the option must exist to use a relationship that is suitable for the palaeoenvironmental conditions. These principles were applied to calculate discharges that formed the Lateglacial palaeochannels 5–15 times wider than the present-day rivers. The calculated mean annual palaeodischarges were only 2–4 times larger than those of the modern rivers. These palaeodischarges have been produced by an annual rainfall of about equal to or only slightly larger than the recent one. The main environmental conditions were: 1) a long winter, the accumulation of sufficient (300–700 mm) amount of water equivalent in snow; 2) short and sharp flood; 3) small water losses during this flood due to low soil permeability under permafrost conditions; 4) long low-water period, when these large channels were almost dry. Therefore, the mean annual discharge appeared to have risen substantially less than did the flood discharge.
- Published
- 2017
12. Northern Hemisphere permafrost extent: Drylands, glaciers and sea floor. Comment to the paper: Obu, J., et al. 2019. Northern Hemisphere permafrost map based on TTOP modeling for 2000–2016 at 1 km2 scale, Earth Science Reviews, 193, 299–316
- Author
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Wojciech Dobiński
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Dry land ,Continental shelf ,Earth science ,Northern Hemisphere ,Glacier ,010502 geochemistry & geophysics ,Permafrost ,01 natural sciences ,General Earth and Planetary Sciences ,Ice sheet ,Scale (map) ,Geology ,Seabed ,0105 earth and related environmental sciences - Abstract
The article published by Obu et al. (2019) estimating the occurrence of permafrost over a Northern Hemisphere. The results published differ from those presented in previous works. This comment highlights the errors introduced in that study, and in a positive note, its cause and proposed solution. The problem remains beyond capabilities of computed models or empirical research. Its solution lies in using the correct categories and land classifications, and clearly defining the medium subjected to freezing. In particular, the correct classification of ice plays a decisive role here. To provide a full picture of the occurrence of permafrost on the Earth surface, three different media must be considered: 1) exposed land, traditionally understood as “dry land”, 2) glaciers and ice sheets together with its bed and 3) the sea floor (continental shelves). The biggest weakness of the published study is not including glaciated areas in their estimations. The authors do not take either a clear position in this crucial matter, despite a radical divergence of opinions has emerged in recent years. Whether and in what way Greenland or other glaciated areas are covered by permafrost remains a pressing issue, as the final determination of the range of the permafrost worldwide depends on it. Until then, any criteria or benchmark used will continue to be ambiguous and open to discussion, maintaining the discrepancy at millions of square kilometers.
- Published
- 2020
13. Alpine permafrost could account for a quarter of thawed carbon based on Plio-Pleistocene paleoclimate analogue.
- Author
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Cheng F, Garzione C, Li X, Salzmann U, Schwarz F, Haywood AM, Tindall J, Nie J, Li L, Wang L, Abbott BW, Elliott B, Liu W, Upadhyay D, Arnold A, and Tripati A
- Subjects
- Carbon analysis, Climate, European Alpine Region, Temperature, Permafrost
- Abstract
Estimates of the permafrost-climate feedback vary in magnitude and sign, partly because permafrost carbon stability in warmer-than-present conditions is not well constrained. Here we use a Plio-Pleistocene lacustrine reconstruction of mean annual air temperature (MAAT) from the Tibetan Plateau, the largest alpine permafrost region on the Earth, to constrain past and future changes in permafrost carbon storage. Clumped isotope-temperatures (Δ
47 -T) indicate warmer MAAT (~1.2 °C) prior to 2.7 Ma, and support a permafrost-free environment on the northern Tibetan Plateau in a warmer-than-present climate. Δ47 -T indicate ~8.1 °C cooling from 2.7 Ma, coincident with Northern Hemisphere glacial intensification. Combined with climate models and global permafrost distribution, these results indicate, under conditions similar to mid-Pliocene Warm period (3.3-3.0 Ma), ~60% of alpine permafrost containing ~85 petagrams of carbon may be vulnerable to thawing compared to ~20% of circumarctic permafrost. This estimate highlights ~25% of permafrost carbon and the permafrost-climate feedback could originate in alpine areas., (© 2022. The Author(s).)- Published
- 2022
- Full Text
- View/download PDF
14. Review on the paper of Zimmermann et al. ‘Sedimentary ancient DNA and pollen reveal the composition of plant organic matter in Late Quaternary permafrost sediments of the Buor Khaya Peninsula (north-eastern Siberia)’
- Author
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Natalia Rudaya
- Subjects
chemistry.chemical_classification ,geography ,geography.geographical_feature_category ,biology ,Geochemistry ,biology.organism_classification ,medicine.disease_cause ,Permafrost ,Khaya ,Ancient DNA ,chemistry ,Peninsula ,Pollen ,medicine ,Organic matter ,Sedimentary rock ,Quaternary ,Geology - Published
- 2016
15. Factors influencing permafrost temperatures across tree line in the uplands east of the Mackenzie Delta, 2004–20101This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.2Polar Continental Shelf Contribution 03611
- Author
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Michael J. Palmer, Christopher R. Burn, and Steven V. Kokelj
- Subjects
Delta ,Climatology ,Taiga ,General Earth and Planetary Sciences ,Physical geography ,Permafrost ,Snow ,Subarctic climate ,Tree line ,Geology ,Tundra ,Vegetation cover - Abstract
Air and near-surface ground temperatures, late-winter snow conditions, and characteristics of the vegetation cover and soil were measured across the forest–tundra transition in the uplands east of the Mackenzie Delta, Northwest Territories, in 2004–2010. Mean late-winter snow depth decreased northward from 73 cm in the subarctic boreal forest near Inuvik to 22 cm in low-shrub tundra. Annual near-surface ground temperatures decreased northward by 0.1–0.3 °C/km near the northern limit of trees, in association with an abrupt change in snow depth. The rate decreased to 0.01–0.06 °C/km in the tundra. The freezing season is twice as long as the thawing season in the region, so measured differences in the regional ground thermal regime were dominated by the contrast in winter surface conditions between forest and tundra.
- Published
- 2012
16. Influence of snow on near-surface ground temperatures in upland and alluvial environments of the outer Mackenzie Delta, Northwest Territories1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada
- Author
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P. D. Morse, Christopher R. Burn, and Steven V. Kokelj
- Subjects
Delta ,Hydrology ,General Earth and Planetary Sciences ,Spatial variability ,Alluvium ,Snow ,Permafrost ,Water content ,Geology ,Alluvial plain ,Active layer - Abstract
Relations between snow cover, active-layer thickness, and near-surface ground temperatures were determined in 2005–2009 for a diverse range of alluvial and upland settings in the outer Mackenzie Delta. Here, the snow cover developed primarily by wind redistribution, with its spatial variation controlled by topography in uplands and vegetation height in alluvial lowlands. Snow cover was the primary influence on freeze-back duration and the mean annual temperature at the top of permafrost (TTOP), with the difference in median TTOP between alluvial (–3.7 °C) and upland (–6.1 °C) settings related to the greater snow depth and soil moisture in the alluvial plain. The active layer was generally deeper in the wet alluvial lowlands, where the average duration of active-layer freeze back (101 days) was nearly double the time taken in the well-drained uplands (55 days). The surface offset (ΔTS; up to 11 °C) dominated the difference between annual mean air temperature (AMAT) and TTOP (ΔT). In alluvial terrain, ΔTS varied with snow depth, but in the uplands, ΔTS was more consistent from site to site. The small thermal offset (
- Published
- 2012
17. Geomorphology of a thermo-erosion gully, Bylot Island, Nunavut, Canada1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.2Polar Continental Shelf Project Contribution 043-11
- Author
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E. Godin and Daniel Fortier
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Water flow ,Continental shelf ,Sinkhole ,Erosion ,General Earth and Planetary Sciences ,Glacier ,Drainage ,Permafrost ,Snow ,Geology - Abstract
A thermo-erosion gully has been monitored in the valley of glacier C-79 on Bylot Island since 1999. The main channel of the gully reached 390 m in length a few months after its initiation and grew between 38 and 50 m/year over the following decade, for an overall approximated average of 75 m/year. In 2009, the total gully length and area, including the main and relict channels, were 2500 m and 25 000 m2, respectively. Gullies affect snow accumulation, and therefore ground temperature, local water flow, and drainage. Sinkholes, gully heads, pools, baydzherakhi, tunnels, and collapses were grouped as a function of time since gully formation in that area. Sinkholes and tunnels were formed every year after gully inception, and baydzherakhi were found in 3–10 year old sections of the gully. Stabilization of the gully floor and sides took about a decade.
- Published
- 2012
18. Climate and ground temperature relations at sites across the continuous and discontinuous permafrost zones, northern Canada1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.2Earth Science Sector (ESS) Contribution 20110128
- Author
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Jennifer Throop, Sharon L. Smith, and Antoni G. Lewkowicz
- Subjects
Hydrology ,Series (stratigraphy) ,Ground temperature ,General Earth and Planetary Sciences ,Applied research ,Physical geography ,Permafrost ,Geology ,Theme (narrative) - Abstract
Climate – ground temperature relations are examined under a range of conditions for 10 sites across northern Canada. The sites are located between 60°N and 83°N and at elevations of 40 to 1840 m above sea level. They encompass various environmental and climatic conditions, with permafrost temperatures that range from just below 0 to –15 °C. The substrates range from bedrock to fine-grained sediment with high ice content, and vegetation types include coniferous forests in the Mackenzie Valley, shrub tundra at high elevation in the southern Yukon Territory, and polar desert in the High Arctic. Permafrost conditions at all of these sites are determined primarily by air temperature, followed by snow and substrate conditions. The apparent thermal diffusivity is relatively high at colder sites and in bedrock and is lower at sites in sediment with high ice content. Snow has a greater influence on air–ground temperature relations at sites where mean annual air temperatures and active-layer moisture contents are relatively high, leading to physically significant latent heat effects and a slower freeze-back of the active layer.
- Published
- 2012
19. Cryostratigraphic record of permafrost degradation and recovery following historic (1898–1992) surface disturbances in the Klondike region, central Yukon Territory1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.2Yukon Geological Survey Contribution 008
- Author
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Wendy R. Clavano, Duane G. Froese, and Fabrice Calmels
- Subjects
Permafrost degradation ,Earth science ,General Earth and Planetary Sciences ,Permafrost ,Geomorphology ,Geology - Abstract
We present a detailed cryostratigraphic reconstruction of the degradation and recovery of near-surface permafrost in the southern Klondike goldfields, central Yukon Territory. Two ice-rich layers are recognized in near-surface permafrost and attributed to thermal impacts following vegetation disturbance. At an undisturbed forest site, the base of the modern active layer is stable. At an adjacent site, where a late twentieth century disturbance of surface vegetation and permafrost degradation occurred, there is evidence of recovery in the form of aggradation (upward shift) of the permafrost table following limited vegetation succession. Underlying both the undisturbed forest and the late twentieth century disturbance is an older thaw unconformity corresponding to a thaw depth of ∼2 m, likely associated with early twentieth century (gold rush era) impacts. Field and air photo surveys allow identification of the nature of the disturbances, while a chronology of the surface disturbance has been established using age estimates from tree rings, and the presence of tritium and post-bomb 14C from organic samples within aggradational ice. Collectively, these data underscore the importance of vegetation cover in maintaining ground temperatures in the discontinuous permafrost zone and suggest that, at least at the study site in recent decades, permafrost shows the potential to recover from disturbance in the modern climatic regime of the region.
- Published
- 2012
20. Modelling and mapping permafrost at high spatial resolution in Wapusk National Park, Hudson Bay Lowlands1This article is one of a series of papers published in this CJES Special Issue on the theme ofFundamental and applied research on permafrost in Canada.2Earth Science Sector Contribution 20110058
- Author
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Xiping Wang, Yu Zhang, Lynda A. Dredge, Heather Stewart, G. Peter Kershaw, Junhua Li, Wanli Wu, Donald McLennan, Larry D. Dyke, Jean Poitevin, Ryan K. Brook, Wendy Sladen, Sheldon Kowalchuk, and Wenjun Chen
- Subjects
Hydrology ,Series (stratigraphy) ,National park ,General Earth and Planetary Sciences ,Applied research ,Physical geography ,Permafrost ,Longitude ,Bay ,Geology ,Latitude ,Theme (narrative) - Abstract
Most spatial modelling of permafrost distribution and dynamics has been conducted at half-degree latitude/longitude or coarser resolution. Such coarse results are difficult to use for land managers and ecologists. Here we mapped permafrost distribution at 30 m × 30 m resolution for a region in the northwest Hudson Bay Lowlands using a process-based model. Land-cover types and leaf area indices were derived from Landsat imagery; peat thickness was estimated from elevation based on field measurements; and climate data were interpolated from station observations. The modelled active-layer thickness and permafrost extent compared well with field observations, demonstrating that modelling and mapping permafrost at a high spatial resolution is practical for terrains such as these lowlands. The map portrayed large variations in active-layer thickness, with land-cover type and peat thickness being the most important controlling variables. The modelled active-layer thickness on average increased by 37% during the twentieth century due to increases in air temperature and precipitation, and permafrost disappeared in some southern areas. The spatial scale of the permafrost maps developed in this study is close to that of the ecosystem and landscape features; therefore, the results are useful for land management and ecosystem assessment.
- Published
- 2012
21. Recent changes in climate and permafrost temperatures at forested and polar desert sites in northern Canada1This article is one of a series of papers published in this CJES Special Issue on the theme ofFundamental and applied research on permafrost in Canada
- Author
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Jennifer Throop, Sharon L. Smith, and Antoni G. Lewkowicz
- Subjects
Arctic ,Taiga ,Global warming ,General Earth and Planetary Sciences ,Magnitude (mathematics) ,Hindcast ,Physical geography ,Forcing (mathematics) ,Permafrost ,Polar desert ,Geology - Abstract
Climate and ground temperature records up to 30 years in length from permafrost monitoring sites in a polar desert at Alert, Nunavut, and a boreal forest at Table Mountain, Northwest Territories, were analyzed by season and year to assess the ground thermal response to recent climate warming. Methods were developed to standardize incomplete ground temperature data sets and to hindcast air temperatures for comparative analysis. The timing and magnitude of climate warming varied, beginning in the 1960s in the Mackenzie Valley and the 1970s in the High Arctic. Ground temperature increases occurred in both regions but varied in magnitude and timing in relation to the external forcing and permafrost conditions. Significant increases in winter air temperatures in both regions appear to be largely responsible for recent increases in ground temperature, particularly at the polar desert sites where snow cover is minimal.
- Published
- 2012
22. Degradation of permafrost beneath a road embankment enhanced by heat advected in groundwater1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada
- Author
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Isabelle de Grandpré, Daniel Fortier, and E. Stephani
- Subjects
Permafrost degradation ,Hydrology ,geography ,geography.geographical_feature_category ,Earth science ,Global warming ,General Earth and Planetary Sciences ,Applied research ,Levee ,Permafrost ,Geology ,Theme (narrative) - Abstract
For the past few decades, northwestern North America has been affected by climate warming, leading to permafrost degradation and instability of the ground. This is problematic for all infrastructure built on permafrost, especially roads and runways. Thaw settlement and soil consolidation promote embankment subsidence and the development of cracks, potholes, and depressions in road pavement. In this study, we investigate highway stability in permafrost terrain at an experimentally built road embankment near Beaver Creek, Yukon. A network of 25 groundwater monitoring wells was installed along the sides of the road to estimate groundwater flow and its thermal impact on the permafrost beneath the road. Data on topography, water-table elevation, ground temperature, and stratigraphy of the soil were collected at the site. The geotechnical properties of each soil layer were determined by laboratory analysis and used to calibrate a two-dimensional groundwater flow model. Field observations showed that water was progressively losing heat as it flowed under the road embankment. Our results suggest that advective heat transfer related to groundwater flow accelerated permafrost degradation under the road embankment.
- Published
- 2012
23. The long-term response of stream flow to climatic warming in headwater streams of interior AlaskaThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming
- Author
-
Amanda J. RinehartA.J. Rinehart and Jeremy B. Jones
- Subjects
Global and Planetary Change ,Hydrology (agriculture) ,Ecology ,Streamflow ,Global warming ,Taiga ,Environmental science ,Climate change ,Forestry ,Ecosystem ,Physical geography ,STREAMS ,Permafrost - Abstract
Warming in the boreal forest of interior Alaska will have fundamental impacts on stream ecosystems through changes in stream hydrology resulting from upslope loss of permafrost, alteration of availability of soil moisture, and the distribution of vegetation. We examined stream flow in three headwater streams of the Caribou–Poker Creeks Research Watershed (CPCRW) in interior Alaska over a 30-year period to determine (i) how stream flow varied among streams draining watersheds with varying extents of permafrost and (ii) evaluate if stream hydrology is changing with loss of permafrost. The three streams drained subcatchments with permafrost extents ranging from 4% to 53%. For each stream, runoff data were analyzed by separating base and storm flow contributions using a local-minimum method and with analysis of flood recession curves. Mean daily runoff during the ice-free season did not significantly vary among streams (mean = 0.57 mm·d–1), although the watersheds with lower permafrost had a greater contribution of base flow. Across years, flow was variable and was related with summer temperature in the watershed with low permafrost and with precipitation in the watershed with high permafrost. With climate warming and loss of permafrost, stream flows will become less responsive to precipitation and headwater streams may become ephemeral.
- Published
- 2010
24. Resilience and vulnerability of permafrost to climate changeThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming
- Author
-
Edward A. G. Schuur, Jennifer Harden, S. Marchenko, Y. Shur, Jonathan O’DonnellJ. O’Donnell, Mikhail Kanevskiy, M. Torre Jorgenson, and Vladimir Romanovsky
- Subjects
Global and Planetary Change ,Ecology ,Taiga ,Vulnerability ,Climate change ,Forestry ,Vegetation ,Snow ,Permafrost ,Environmental science ,Ecosystem ,Physical geography ,Resilience (network) - Abstract
The resilience and vulnerability of permafrost to climate change depends on complex interactions among topography, water, soil, vegetation, and snow, which allow permafrost to persist at mean annual air temperatures (MAATs) as high as +2 °C and degrade at MAATs as low as –20 °C. To assess these interactions, we compiled existing data and tested effects of varying conditions on mean annual surface temperatures (MASTs) and 2 m deep temperatures (MADTs) through modeling. Surface water had the largest effect, with water sediment temperatures being ~10 °C above MAAT. A 50% reduction in snow depth reduces MADT by 2 °C. Elevation changes between 200 and 800 m increases MAAT by up to 2.3 °C and snow depths by ~40%. Aspect caused only a ~1 °C difference in MAST. Covarying vegetation structure, organic matter thickness, soil moisture, and snow depth of terrestrial ecosystems, ranging from barren silt to white spruce ( Picea glauca (Moench) Voss) forest to tussock shrub, affect MASTs by ~6 °C and MADTs by ~7 °C. Groundwater at 2–7 °C greatly affects lateral and internal permafrost thawing. Analyses show that vegetation succession provides strong negative feedbacks that make permafrost resilient to even large increases in air temperatures. Surface water, which is affected by topography and ground ice, provides even stronger negative feedbacks that make permafrost vulnerable to thawing even under cold temperatures.
- Published
- 2010
25. Culturable microbes in shallow groundwater underlying ornithogenic soil of Cape Hallett, AntarcticaThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology
- Author
-
Jackie Aislabie, Ajit K. Sarmah, and Janine Ryburn
- Subjects
biology ,Ecology ,Soil organic matter ,Immunology ,Bacteroidetes ,Soil classification ,General Medicine ,biology.organism_classification ,Permafrost ,Applied Microbiology and Biotechnology ,Microbiology ,Actinobacteria ,Microbial population biology ,Environmental chemistry ,Genetics ,Environmental science ,Proteobacteria ,Molecular Biology ,Groundwater - Abstract
The objective of this study was to investigate the culturable psychrotolerant microbial community in groundwater from Seabee Hook, Antarctica. Shallow groundwater can be present in coastal regions at higher latitudes during the Antarctic summer. Perched groundwater atop ice-cemented permafrost occurs on Seabee Hook, Cape Hallett, at depths from 5 to 80 cm below the soil surface. Compared with terrestrial water from other sites in Antarctica, the groundwater was high in salt and nutrients, reflecting proximity to the sea and ornithogenic soil. Microbial communities in groundwater samples from Seabee Hook exhibited aerobic metabolism of14C-acetate at 5 °C. Numbers of culturable aerobic heterotrophs in the samples ranged from 6 colony-forming units·mL–1, and similar numbers of microaerophiles and nitrate reducers were detected. In contrast, numbers of nitrifiers, sulfate reducers, and iron reducers were up to 1000-fold lower. All cultures were incubated at 5 °C. Aerobic heterotrophic bacteria isolated from the groundwater were assigned to Actinobacteria, Proteobacteria, or Bacteroidetes. The isolates were most similar to cultured bacteria from Antarctic soil or sediment and were cold, salt, and alkaline pH tolerant, indicating they are adapted to in situ conditions.
- Published
- 2009
26. Bacterial community structure and carbon turnover in permafrost-affected soils of the Lena Delta, northeastern SiberiaThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology
- Author
-
Susanne Liebner, Dirk Wagner, and Svenja Kobabe
- Subjects
2. Zero hunger ,chemistry.chemical_classification ,Total organic carbon ,0303 health sciences ,030306 microbiology ,Ecology ,Soil organic matter ,Immunology ,Soil classification ,General Medicine ,Soil carbon ,15. Life on land ,Permafrost ,Applied Microbiology and Biotechnology ,Microbiology ,Carbon cycle ,03 medical and health sciences ,chemistry ,13. Climate action ,Genetics ,Environmental science ,Soil horizon ,Organic matter ,Molecular Biology ,030304 developmental biology - Abstract
Arctic permafrost environments store large amounts of organic carbon. As a result of global warming, intensified permafrost degradation and release of significant quantities of the currently conserved organic matter is predicted for high latitudes. To improve our understanding of the present and future carbon dynamics in climate sensitive permafrost ecosystems, the present study investigates structure and carbon turnover of the bacterial community in a permafrost-affected soil of the Lena Delta (72°22′N, 126°28′E) in northeastern Siberia. 16S rRNA gene clone libraries revealed the presence of all major soil bacterial groups and of the canditate divisions OD1 and OP11. A shift within the bacterial community was observed along the soil profile indicated by the absence of Alphaproteobacteria and Betaproteobacteria and a simultaneous increase in abundance and diversity of fermenting bacteria like Firmicutes and Actinobacteria near the permafrost table. BIOLOG EcoPlates were used to describe the spectrum of utilized carbon sources of the bacterial community in different horizons under in situ temperature conditions in the presence and absence of oxygen. The results revealed distinct qualitative differences in the substrates used and the turnover rates under oxic and anoxic conditions. It can be concluded that constantly negative redox potentials as characteristic for the near permafrost table horizons of the investigated soil did effectively shape the structure of the indigenous bacterial community limiting its phylum-level diversity and carbon turnover capacity.
- Published
- 2009
27. Papers Presented to Commemorate the Legacy to Permafrost Science of Professor J. Ross Mackay (1915-2014).
- Author
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Burn, Christopher R.
- Subjects
PERMAFROST ,GEOMORPHOLOGY ,GEOCHEMISTRY - Published
- 2017
- Full Text
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28. Hotspots and trends in frozen soils research in 2010–2019.
- Author
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Liu, Wenhao, Li, Ren, Shi, Xiaoqian, Wu, Tonghua, and Wu, Xiao Dong
- Subjects
TUNDRAS ,FROZEN ground ,CARBON cycle ,BIBLIOMETRICS ,LANDSAT satellites ,CLIMATE change - Abstract
In the context of climate change, research on frozen soils has attracted much attention in recent years, and numerous research papers have been published on these topics in the last decade. However, the present status and developmental trends in frozen soils research have not been reported systematically. Herein, a bibliometric analysis was conducted using 7,108 research papers on frozen soils published between 2010 and 2019. The results indicate that: (a) although the number of articles published increased from 432 in 2010 to 1,066 in 2019, the average number of citations per paper reached a maximum of 5.40 in 2014, and subsequently decreased to 2.99 in 2019; (b) China, the USA, and Canada ranked first to third in terms of total papers; (c) the most popular author keywords were boreal, tundra, Landsat, lakes, decomposition, dissolved organic carbon, permafrost thaw, and carbon cycle; and (d) the five most popular research topics in 2010–2019 were the characteristics and factors influencing frozen soils, the Arctic carbon cycle under the background of its complex environment, permafrost changes on the Qinghai–Tibet Plateau in the context of climate change, ancient frozen soils in various historical periods, and frozen soils in the Arctic. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Transient and Transition Factors in Modeling Permafrost Thaw and Groundwater Flow.
- Author
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Langford JE, Schincariol RA, Nagare RM, Quinton WL, and Mohammed AA
- Subjects
- Canada, Climate, Ecosystem, Groundwater, Permafrost
- Abstract
Permafrost covers approximately 24% of the Northern Hemisphere, and much of it is degrading, which causes infrastructure failures and ecosystem transitions. Understanding groundwater and heat flow processes in permafrost environments is challenging due to spatially and temporarily varying hydraulic connections between water above and below the near-surface discontinuous frozen zone. To characterize the transitional period of permafrost degradation, a three-dimensional model of a permafrost plateau that includes the supra-permafrost zone and surrounding wetlands was developed. The model is based on the Scotty Creek basin in the Northwest Territories, Canada. FEFLOW groundwater flow and heat transport modeling software is used in conjunction with the piFreeze plug-in, to account for phase changes between ice and water. The Simultaneous Heat and Water (SHAW) flow model is used to calculate ground temperatures and surface water balance, which are then used as FEFLOW boundary conditions. As simulating actual permafrost evolution would require hundreds of years of climate variations over an evolving landscape, whose geomorphic features are unknown, methodologies for developing permafrost initial conditions for transient simulations were investigated. It was found that a model initialized with a transient spin-up methodology, that includes an unfrozen layer between the permafrost table and ground surface, yields better results than with steady-state permafrost initial conditions. This study also demonstrates the critical role that variations in land surface and permafrost table microtopography, along with talik development, play in permafrost degradation. Modeling permafrost dynamics will allow for the testing of remedial measures to stabilize permafrost in high value infrastructure environments., (© 2019, National Ground Water Association.)
- Published
- 2020
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30. RS WilliamsJr and JG Ferrigno eds. (2012). Satellite image atlas of glaciers of the world. State of the Earth’s cryosphere at the beginning of the 21st century: glaciers, global snow cover, floating ice, and permafrost and periglacial environments. (USGS Professional Paper 1386- A) United States Geological Survey, Denver, CO, 546pp. ISBN 987-0-607-98287-9, softback (also available at http://pubs.usgs.gov/pp/p1386a/)
- Author
-
Olav Orheim
- Subjects
geography ,geography.geographical_feature_category ,Atlas (topology) ,Satellite image ,Cryosphere ,Glacier ,Physical geography ,Permafrost ,Geology ,Snow cover ,Earth-Surface Processes - Published
- 2013
31. The concept of cryo-conditioning in landscape evolution – Comment to the paper published by Ivar Berthling and Bernd Etzelmüller, Quaternary Research 75 (2011) 378–384
- Author
-
Wojciech Dobiński
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Landform ,Earth science ,Glacier ,Permafrost ,Term (time) ,Arts and Humanities (miscellaneous) ,General Earth and Planetary Sciences ,Glacial period ,Quaternary ,Geology ,Earth-Surface Processes - Abstract
The term "cryo-conditioning," proposed by the authors for classifying specific landform association in periglacial landscapes, needs to be defined more precisely. A starting point could be the proper understanding of the term "Cryo-" in the various compound words found in various disciplines. This is also important for a correct understanding of the proposed concepts, since it concerns one of the most important processes in nature: the phase transition of water between solid and liquid. Cold-temperate transition surfaces in polythermal glaciers and at the permafrost base in their forelands can act as a specific hub between the glacial and periglacial domains.
- Published
- 2012
32. The Global Terrestrial Network for Permafrost Database: metadata statistics and prospective analysis on future permafrost temperature and active layer depth monitoring site distribution.
- Author
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Biskaborn, B. K., Lanckman, J.-P., Lantuit, H., Elger, K., Streletskiy, D. A., Cable, W. L., and Romanovsky, V. E.
- Subjects
PERMAFROST ,FROZEN ground ,TEMPERATURE ,BOREHOLES ,DATABASES ,CLIMATE change ,METADATA - Abstract
The Global Terrestrial Network for Permafrost (GTN-P) provides the first dynamic database associated with the Thermal State of Permafrost (TSP) and the Circumpolar Active Layer Monitoring (CALM) programs, which extensively collect permafrost temperature and active layer thickness data from Arctic, Antarctic and Mountain permafrost regions. The purpose of the database is to establish an "early warning system" for the consequences of climate change in permafrost regions and to provide standardized thermal permafrost data to global models. In this paper we perform statistical analysis of the GTN-P metadata aiming to identify the spatial gaps in the GTN-P site distribution in relation to climate-effective environmental parameters. We describe the concept and structure of the Data Management System in regard to user operability, data transfer and data policy. We outline data sources and data processing including quality control strategies. Assessment of the metadata and data quality reveals 63% metadata completeness at active layer sites and 50% metadata completeness for boreholes. Voronoi Tessellation Analysis on the spatial sample distribution of boreholes and active layer measurement sites quantifies the distribution inhomogeneity and provides potential locations of additional permafrost research sites to improve the representativeness of thermal monitoring across areas underlain by permafrost. The depth distribution of the boreholes reveals that 73% are shallower than 25 m and 27% are deeper, reaching a maximum of 1 km depth. Comparison of the GTN-P site distribution with permafrost zones, soil organic carbon contents and vegetation types exhibits different local to regional monitoring situations on maps. Preferential slope orientation at the sites most likely causes a bias in the temperature monitoring and should be taken into account when using the data for global models. The distribution of GTN-P sites within zones of projected temperature change show a high representation of areas with smaller expected temperature rise but a lower number of sites within arctic areas were climate models project extreme temperature increase. This paper offers a scientific basis for planning future permafrost research sites on large scales. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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33. Statistical Evaluation of Seismic Velocity Models of Permafrost.
- Author
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Ji, Xiaohang, Xiao, Ming, Martin, Eileen R., and Zhu, Tieyuan
- Subjects
SEISMIC wave velocity ,SEISMIC waves ,PERMAFROST ,GLOBAL warming ,COLD regions ,INFRASTRUCTURE (Economics) ,TUNDRAS - Abstract
The warming climate in high-latitude permafrost regions is leading to permafrost degradation. Estimating seismic wave velocities in permafrost could help predict the geomechanical properties of permafrost and provide information to plan and design resilient civil infrastructure in cold regions. This paper evaluates the performance of seven models when predicting the seismic wave velocities of permafrost statistically; these models are the time-average, Zimmerman and King, Minshull et al., weighted equation, three-phase, Biot–Gassmann theory modified by Lee (BGTL), and Dou et al. models. The data used in the evaluation are from published laboratory and in situ data, which includes 369 data points for joint P and S wave velocities from nine publications and 943 unfrozen water content data points from 12 publications. The unfrozen water content that is used in these models is determined from a modified Dall'Amico's model that is proposed, which is evaluated against six existing unfrozen water content models based on soil temperature. This paper finds that saturated nonsaline permafrost generally shares similar linear trends between the P and S wave velocities, regardless of soil type, porosity, grain size, and temperature. Fitting all existing data, an empirical linear relationship is derived between the P and S wave velocities. Among the seven models evaluated, the Minshull et al. and BGTL models are the most accurate when predicting the seismic velocities of permafrost. Practical Applications: Unfrozen water content and seismic wave velocity models are valuable tools for quantitatively predicting permafrost dynamics and degradation, with practical applications in various engineering areas with permafrost environments. As permafrost thaws due to rising temperatures, these models could be used to guide the quantitative interpretation of geophysical changes in subsurface conditions, assess the potential for ground instability, and predict future permafrost degradation. Unfrozen water content models are used to predict the percentage of unfrozen water within permafrost, which links the changes with permafrost temperature. Unfrozen water content models of permafrost are essential when assessing permafrost thaw, thermal performance, heat transfer processes in permafrost, and the effect of civil infrastructure on permafrost (Chen et al.,). The seismic wave velocity models could help engineers assess the subsurface conditions in permafrost areas; this assessment is crucial for environmental and seismic monitoring, land use planning, infrastructure design and construction, and natural resources exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Bibliometric Analysis of the Permafrost Research: Developments, Impacts, and Trends.
- Author
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Du, Qingsong, Li, Guoyu, Chen, Dun, Zhou, Yu, Qi, Shunshun, Wang, Fei, Mao, Yuncheng, Zhang, Jun, Cao, Yapeng, Gao, Kai, Wu, Gang, Li, Chunqing, and Wang, Yapeng
- Subjects
BIBLIOMETRICS ,PERMAFROST ,SYNTHETIC aperture radar ,RESEARCH & development ,WATER shortages ,ENVIRONMENTAL degradation - Abstract
Permafrost is a significant part of the cryosphere, which has gained increasing attention from scientists, policy-makers, and the general public due to global warming, environmental degradation, water shortages, and intense human activities. Although many permafrost research review articles have been published, these studies were predominantly limited to either one subject or one field, while systematic studies about permafrost based on bibliometric analysis methods remain limited. We aim to fill this gap by conducting a bibliometric analysis of 13,697 articles in the field of permafrost research from 1942 to 2021, collected from the Web of Science core collection database. The results indicate that permafrost research is a typically multi-author, multi-country, and multi-institution cooperative field, involved in many research fields. The cumulative number of publications has presented an exponential increase over the past 80 years, with an average annual growth rate of 10.40%. Since 2000, China has seen a rapid growth in the number of publications per year, surpassing the USA in 2016 and leading in the years since then. In addition, the authors from China have great contributions in publications, and there is good room for permafrost development in the future according to the authors' M-index ranking. After the analysis of authors' keywords, we found that, compared to the conventional methods, machine learning and interferometric synthetic aperture radar (InSAR) are new technological approaches introduced in recent years, and the Qinghai–Tibet Plateau has become a popular study area. The results presented here can help related researchers, scholars, and students in the field to better understand the past developments, current status, and future trends of permafrost research. Furthermore, this paper presents and expands the general process of the bibliometric method used in permafrost studies, which can provide researchers with new inspirations and improve discipline research approach. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Periglacial cryostratigraphy, palaeoenvironments and processes: Papers from a Periglacial Workshop, University of Wales, Cardiff, UK, 16–17 December 1997. Preface
- Author
-
Julian B. Murton and Charles Harris
- Subjects
Permafrost ,Archaeology ,Geology ,Earth-Surface Processes - Published
- 1998
36. Northern Hemisphere permafrost extent: Drylands, glaciers and sea floor. Comment to the paper: Obu, J., et al. 2019. Northern Hemisphere permafrost map based on TTOP modeling for 2000–2016 at 1 km2 scale, Earth Science Reviews, 193, 299–316
- Author
-
Dobiński, Wojciech
- Abstract
The article published by Obu et al. (2019) estimating the occurrence of permafrost over a Northern Hemisphere. The results published differ from those presented in previous works. This comment highlights the errors introduced in that study, and in a positive note, its cause and proposed solution. The problem remains beyond capabilities of computed models or empirical research. Its solution lies in using the correct categories and land classifications, and clearly defining the medium subjected to freezing. In particular, the correct classification of ice plays a decisive role here. To provide a full picture of the occurrence of permafrost on the Earth surface, three different media must be considered: 1) exposed land, traditionally understood as "dry land", 2) glaciers and ice sheets together with its bed and 3) the sea floor (continental shelves). The biggest weakness of the published study is not including glaciated areas in their estimations. The authors do not take either a clear position in this crucial matter, despite a radical divergence of opinions has emerged in recent years. Whether and in what way Greenland or other glaciated areas are covered by permafrost remains a pressing issue, as the final determination of the range of the permafrost worldwide depends on it. Until then, any criteria or benchmark used will continue to be ambiguous and open to discussion, maintaining the discrepancy at millions of square kilometers. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. Review of the Impact of Permafrost Thawing on the Strength of Soils.
- Author
-
Ajmera, Beena and Emami Ahari, Hossein
- Subjects
LANDSLIDES ,SHEAR strength of soils ,PERMAFROST ,FROZEN ground ,SOIL cohesion ,SOILS ,GLOBAL warming ,TUNDRAS - Abstract
Global warming is causing unprecedented changes to permafrost regions with amplified effects in the Arctic through a phenomenon known as Arctic amplification. This intensified climate warming thaws both the discontinuous and continuous permafrost resulting in changes in the mechanical properties of the soils found in these regions. Since permafrost regions constitute nearly 24% of the Northern Hemisphere, understanding the strength of soils in thawed conditions is essential to analyze the stability of existing structures, and to design safer and more economical infrastructure in these regions. Specifically, thawing of the permafrost is causing considerable reductions in its strength of soils, which may lead to massive landslides, foundation failures, and so forth. Since frozen soil is a multiphase structure that consists of soil particles, unfrozen water, ice, and air, each constituent will influence the mechanical properties. This paper reviews the current state of knowledge of the impact of temperature, volumetric ice content, unfrozen water content, and frozen density on the compressive strength, peak shear strength, residual shear strength, undrained shear strength, and tensile strength of soils. The undrained shear strength of soil is said to have a linear correlation with temperature. In addition, the undrained cohesion of soil was found to depend on the temperature, whereas the undrained friction angle of soil was significantly influenced by volumetric ice content. An increase in the volumetric ice content up to 80% to 90% will cause a reduction in the peak and residual deviatoric stresses. In addition, an increase in volumetric ice content resulted in an increase in the compressive strength of the soil. The tensile and compressive strengths were found to be functions of the unfrozen water content. Global warming is causing the temperature of the permafrost, which is permanently frozen ground, to rise. This paper provides valuable insights into the impact of the changes in this ambient temperature on the strength of frozen soils in permafrost regions for a wide range of applications. Such insights are crucial for the design of resilient and stable infrastructure, such as foundations, embankments, and retaining walls, in which consideration of the reduced strength of thawed soils due to climate change will be necessary. In addition, the knowledge will allow for better management of vulnerable areas prone to landslides and erosion caused by the weakened soil strength permitting the implementation of mitigation measures before lives are lost and costly economic damages are incurred. Finally, this information will aid in early warning systems, emergency planning, and decision making to minimize the impact of hazards on human settlements and infrastructure. In this paper, a review of the current state of knowledge regarding the strength of frozen soils and the associated fluctuations in these strengths because of a rise in temperature are presented. Guidelines on the best practices for sample preparation and testing along with correlations to estimate various strength parameters are also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Analysis and Applications of the Two Phases Closed Thermosyphon Technology in the Highways in Permafrost Regions: A Review.
- Author
-
Du, Shuai and Ye, Zeliang
- Subjects
PERMAFROST ,ROAD construction ,ASPHALT pavements ,HEAT pipes ,GLOBAL warming ,INTELLIGENT transportation systems - Abstract
Featured Application: This review concludes the advantages of heat pipe technology and its application in permafrost regions are summarized, which can also provide recommendations for permafrost protection measures. Permafrost spans approximately 23–25% of the land in the northern hemisphere, primarily found in Russia, Canada, USA, and China. Numerous engineering projects, particularly those related to transportation, are situated within these permafrost regions. Due to the impact of highway construction and global warming, the permafrost beneath the infrastructure is deteriorating, leading to significant damage. Two phases closed thermosyphon (TPCT) is a widely accepted green countermeasure against the problem in permafrost regions. Although it has been applied to prevent permafrost degradation, their application presents significant challenges on account of the stronger endothermic action of asphalt pavement. This paper focused on a review of the thermosyphon technology and application in the permafrost. Moreover, the article highlighted the excellent working performance of the TPCT that improves the stability of the infrastructures and prevents it degrading due its excellent efficiency in terms of heat transfer. The industrial applications of the TPCT were also summarized, along with their limitations. Ultimately, the findings presented in this paper can offer crucial insights for future TPCT design and development in permafrost areas. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. The changing permafrost environment under desertification and the heat transfer mechanism in the Qinghai-Tibetan Plateau.
- Author
-
Lan T, Lai Y, Gao J, Luo X, and Ma Q
- Subjects
- Tibet, Soil chemistry, Hot Temperature, Permafrost
- Abstract
With the development of desertification in the Qinghai-Tibet Plateau (QTP), aeolian sand becomes the remarkable local factor affecting the thermal state of permafrost along the Qinghai-Tibet Engineering Corridor (QTEC). In this study, a model experiment was conducted to analyze the impact of thickness and water content of aeolian sand on its thermal effect, and a hydro-thermo-vapor coupling model of frozen soil was carried out to reveal the heat transfer mechanism of the aeolian sand layer (ASL) with different thicknesses and its hydrothermal effect on permafrost. The results indicate that: (1) ASL with the thickness larger than 80 cm has the property of converting precipitation into soil water. The thicker the ASL, the more precipitation infiltrates and accumulates in the soil layer. (2) The cooling effect of ASL on permafrost results from the lower net surface radiation, causing the annual average surface heat flux shifting from heat inflow to heat outflow. The warming effect of ASL on permafrost results from the increasing convective heat accompanying the infiltrated precipitation. (3) As the ASL thickens, the thermal effect of ASL on permafrost gradually shifts from the cooling effect dominated by heat radiation and heat conduction to the warming effect dominated by precipitation infiltration and heat convection. The warming effect of thick ASL on permafrost requires a certain amount of years to manifest, and the critical thickness is suggested to be larger than 120 cm., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
40. A review on mathematical modeling of microbial and plant induced permafrost carbon feedback.
- Author
-
Fasaeiyan N, Jung S, Boudreault R, Arenson LU, and Maghoul P
- Subjects
- Carbon Cycle, Soil Microbiology, Models, Theoretical, Ecosystem, Soil chemistry, Permafrost, Plants metabolism, Carbon analysis, Carbon metabolism
- Abstract
This review paper analyses the significance of microbial activity in permafrost carbon feedback (PCF) and emphasizes the necessity for enhanced modeling tools to appropriately predict carbon fluxes associated with permafrost thaw. Beginning with an overview of experimental findings, both in situ and laboratory, it stresses the key role of microbes and plants in PCF. The research investigates several modeling techniques, starting with current models of soil respiration and plant-microorganism interactions built outside of the context of permafrost, and then moving on to specific models dedicated to PCF. The review of the current literature reveals the complex nature of permafrost ecosystems, where various geophysical factors have considerable effects on greenhouse gas emissions. Soil properties, plant types, and time scales all contribute to carbon dynamics. Process-based models are widely used for simulating greenhouse gas production, transport, and emissions. While these models are beneficial at capturing soil respiration complexity, adjusting them to the unique constraints of permafrost environments often calls for novel process descriptions for proper representation. Understanding the temporal coherence and time delays between surface soil respiration and subsurface carbon production, which are controlled by numerous parameters such as soil texture, water content, and temperature, remains a challenge. This review highlights the need for comprehensive models that integrate thermo-hydro-biogeochemical processes to understand permafrost system dynamics in the context of changing climatic circumstances. Furthermore, it emphasizes the need for rigorous validation procedures to reduce model complexity biases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
41. Dissolved organic matter quality in thermokarst lake water and sediments across a permafrost gradient, Western Siberia.
- Author
-
Kurashev DG, Manasypov RM, Raudina TV, Krickov IV, Lim AG, and Pokrovsky OS
- Subjects
- Siberia, Environmental Monitoring, Humic Substances analysis, Organic Chemicals analysis, Lakes chemistry, Permafrost, Geologic Sediments chemistry, Geologic Sediments analysis
- Abstract
Thermokarst (thaw) lakes of permafrost peatlands are among the most important sentinels of climate change and sizable contributors of greenhouse gas emissions (GHG) in high latitudes. These lakes are humic, often acidic and exhibit fast growing/drainage depending on the local environmental and permafrost thaw. In contrast to good knowledge of the thermokarst lake water hydrochemistry and GHG fluxes, the sediments pore waters remain virtually unknown, despite the fact that these are hot spots of biogeochemical processes including GHG generation. Towards better understating of dissolved organic matter (DOM) quality at the lake water - sediment interface and in the sediments pore waters, here we studied concentration and optical (UV, visual) properties of DOM of 11 thermokarst lakes located in four permafrost zones of Western Siberia Lowland. We found systematic evaluation of DOM concentration, SUVA and various optical parameters along the vertical profile of lake sediments. The lake size and hence, the stage of lake development, had generally weak control on DOM quality. The permafrost zone exhibited clear impact on DOM porewater concentration, optical characteristics, aromaticity and weight average molecular weight (WAMW). The lowest quality of DOM, reflected in highest SUVA and WAMW, corresponding to the dominance of terrestrial sources, was observed at the southern boundary of the permafrost, in the sporadic/discontinuous zone. This suggests active mobilization of organic matter leachates from the interstitial peat and soil porewaters to the lake, presumably via subsurface or suprapermafrost influx. Applying a substitute space for time scenario for future evolution of OM characteristics in thermokarst lake sediments of Western Siberia, we foresee a decrease of DOM quality, molecular weight and potential bioavailability in lakes of continuous permafrost zone, and an increase in these parameters in the sporadic/discontinuous permafrost zone., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
42. Metagenomic analyses of the late Pleistocene permafrost - additional tools for reconstruction of environmental conditions.
- Author
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Rivkina, E., Petrovskaya, L., Vishnivetskaya, T., Krivushin, K., Shmakova, L., Tutukina, M., Meyers, A., and Kondrashov, F.
- Subjects
PLIOCENE-Pleistocene boundary ,METAGENOMICS ,PERMAFROST ,ANALYTICAL geochemistry ,FROZEN ground - Abstract
A comparative analysis of the metagenomes from two 30 000 year-old permafrost samples, one of lake-alluvial origin and the other from late Pleistocene Ice Complex sediments, revealed significant differences within microbial communities. The late Pleistocene Ice Complex sediments (which have been characterized by the absence of methane with lower values of redox-potential and Fe
2+ content) showed both a low abundance of methanogenic archaea and enzymes from the carbon, nitrogen and sulfur cycles. The metagenomic and geochemical analyses described in the paper provide evidence that the formation of the late Pleistocene Ice Complex sediments likely took place under much more aerobic conditions than lake-alluvial sediments. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
43. Phototrophic pigment diversity and picophytoplankton abundance in permafrost thaw lakes.
- Author
-
Przytulska, A., Comte, J., Crevecoeur, S., Lovejoy, C., Laurion, I., and Vincent, W. F.
- Subjects
FROZEN ground ,LAKES ,PIGMENTS ,PERMAFROST ,GROUND ice - Abstract
Permafrost thaw lakes (thermokarst lakes) are widely distributed across the northern landscape, and are known to be biogeochemically active sites that emit large amounts of carbon to the atmosphere as CH
4 and CO2 . However, the abundance and composition of the photosynthetic communities that consume CO2 have been little explored in this ecosystem type. In order to identify the major groups of phototrophic organisms and their controlling variables, we sampled 12 permafrost thaw lakes along a permafrost degradation gradient in northern Québec, Canada. Additional samples were taken from 5 rock-basin reference lakes in the region to determine if the thaw waters differed in limnological properties and phototrophs. Phytoplankton community structure was determined by high performance liquid chromatography analysis of their photoprotective and photosynthetic pigments, and autotrophic picoplankton concentrations were assessed by flow cytometry. One of the black colored lakes located in a andscape of rapidly degrading palsas (permafrost mounds) was selected for high-throughput 18S rRNA sequencing to help interpret the pigment and cytometry data. The results showed that the limnological properties of the thaw lakes differed significantly from the reference lakes, and were more highly stratified. However, both waterbody types contained similarly diverse phytoplankton groups, with dominance of the pigment assemblages by fucoxanthin-containing taxa, as well as chlorophytes, cryptophytes and cyanobacteria. Chlorophyll a concentrations (Chl a) were correlated with total phosphorus (TP), and both were significantly higher in the thaw lakes (overall means of 3.3 μg Chl a L-1 and 34 μg TP L-1 ) relative to the reference lakes (2.0 μg Chl a L-1 and 8.2 μg TP L-1 ). Stepwise multiple regression of Chl a against the other algal pigments showed that it was largely a function of lutein, fucoxanthin and peridinin (R² = 0.78). The bottom waters of two of the thaw lakes also contained high concentrations of bacteriochlorophyll d, showing the presence of green photosynthetic sulphur bacteria. The molecular analyses indicated a relatively minor contribution of diatoms, while chrysophytes, dinoflagellates and chlorophytes were well represented; the heterotrophic eukaryote fraction was dominated by numerous ciliate taxa, and also included Heliozoa, Rhizaria, chytrids and flagellates. Autotrophic picoplankton occurred in cell concentrations up to 8.8 × 105 mL-1 (picocyanobacteria) and 4.6 × 105 mL-1 (picoeukaryotes). Both groups of picophytoplankton were positively correlated with total phytoplankton abundance, as measured by Chl a; picocyanobacteria were inversely correlated with dissolved organic carbon, while picoeukaryotes were correlated with conductivity. Despite their net heterotrophic character, subarctic thaw lakes are rich habitats for diverse phototrophic communities. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
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44. The GRENE-TEA Model Intercomparison Project (GTMIP): overview and experiment protocol for Stage 1.
- Author
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S. Miyazaki, K. Saito, Mori, J., Yamazaki, T., Ise, T., Arakida, H., Hajima, T., Iijima, Y., Machiya, H., Sueyoshi, T., Yabuki, H., Burke, E. J., Hosaka, M., Ichii, K., Ikawa, H., Ito, A., Kotani, A., Matsuura, Y., Niwano, M., and Nitta, T.
- Subjects
CLIMATE change research ,BIOGEOCHEMISTRY ,ENERGY budget (Geophysics) ,SNOW ,PERMAFROST ,SCIENTISTS - Abstract
As part of the terrestrial branch of the Japan-funded Arctic Climate Change Research Project (GRENE-TEA), which aims to clarify the role and function of the Arctic terrestrial system in the climate system, and assess the influence of its changes on a global 5 scale, this model intercomparison project (GTMIP) is planned and being conducted to (1) enhance communication and understanding between the "minds and hands" (i.e., between the modelling and field scientists) and (2) assess the uncertainty and variations stemming from variability in model implementation/design and in model outputs due to climatic and historical conditions in the Arctic terrestrial regions. This paper 10 provides an overview and the experiment protocol of Stage 1 of the project, site simulations driven by statistically fitted data created using the GRENE-TEA site observations for the last three decades. The target metrics for the model evaluation cover key processes in both physics and biogeochemistry, including energy budgets, snow, permafrost, phenology, and carbon budgets. The preliminary results on four metrics 15 (annual mean latent heat flux, annual maximum snow depth, gross primary production, and net ecosystem production) already demonstrate the range of variations in reproducibility among existing models and sites. Full analysis on annual as well as seasonal time scales, to be conducted upon completion of model outputs submission, will delineate inter-dependence among the key processes, and provide the clue for improving 20 the model performance. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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45. Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973-2013.
- Author
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Clow, G. D.
- Subjects
TEMPERATURE measurements ,BOREHOLES ,PERMAFROST ,COASTS - Abstract
A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented. The 23-element array is located on the Arctic Slope of Alaska, a region of cold continuous permafrost. Most of the monitoring wells are situated on the arctic coastal plain between the Brooks Range and the Arctic Ocean, while others are in the foothills to the south. The data represent the true temperatures in the wellbores and surrounding rocks at the time of the measurements; they have not been corrected to remove the thermal disturbance caused by drilling the wells. With a few exceptions, the drilling disturbance is estimated to have been of order 0.1 K or less by 1989. Thus, most of the temperature measurements acquired during the last 25 yr are little affected by the drilling disturbance. The data contribute to ongoing efforts to monitor changes in the thermal state of permafrost in both hemispheres by the Global Terrestrial Network for Permafrost (GTN-P), one of the primary subnetworks of the Global Terrestrial Observing System (GTOS). The data will also be useful for refining our basic understanding of the physical conditions in permafrost in arctic Alaska, as well as provide important information for validating predictive models used for climate impact assessments. The processed data are available from the ACADIS repository at doi:10.5065/D6N014HK. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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46. High biological N fixation potential dominated by heterotrophic diazotrophs in alpine permafrost rivers on the Qinghai‒Tibet Plateau.
- Author
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Xin Y, Gao Q, Chen X, Sun S, Liu J, Gao H, Zhou J, and Xia X
- Subjects
- Tibet, Heterotrophic Processes, Bacteria metabolism, Nitrogen, Nitrogen Fixation, Rivers, Permafrost
- Abstract
Biological nitrogen (N) fixation is a pivotal N source in N-deficient ecosystems. The Qinghai‒Tibet Plateau (QTP) region, which is assumed to be N limited and suboxic, is an ideal habitat for diazotrophs. However, the diazotrophic communities and associated N fixation rates in these high-altitude alpine permafrost QTP rivers remain largely unknown. Herein, we examined diazotrophic communities in the sediment and biofilm of QTP rivers via the nitrogenase (nifH) gene sequencing and assessed their N fixing activities via a
15 N isotope incubation assay. Strikingly, anaerobic heterotrophic diazotrophs, such as sulfate- and iron-reducing bacteria, had emerged as dominant N fixers. Remarkably, the nifH gene abundance and N fixation rates increased with altitude, and the average nifH gene abundance (2.57 ± 2.60 × 108 copies g-1 ) and N fixation rate (2.29 ± 3.36 nmol N g-1 d-1 ) surpassed that documented in most aquatic environments (nifH gene abundance: 1.31 × 105 ∼ 2.57 × 108 copies g-1 , nitrogen fixation rates: 2.34 × 10-4 ∼ 4.11 nmol N g-1 d-1 ). Such distinctive heterotrophic diazotrophic communities and high N fixation potential in QTP rivers were associated with low-nitrogen, abundant organic carbon and unique C:N:P stoichiometries. Additionally, the significant presence of psychrophilic bacteria within the diazotrophic communities, along with the enhanced stability and complexity of the diazotrophic networks at higher altitudes, clearly demonstrate the adaptability of diazotrophic communities to extreme cold and high-altitude conditions in QTP rivers. We further determined that altitude, coupled with organic carbon and phosphorus, was the predominant driver shaping diazotrophic communities and their N-fixing activities. Overall, our study reveals high N fixation potential in N-deficient QTP rivers, which provides novel insights into nitrogen dynamics in alpine permafrost rivers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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47. Periglaciology: Review and Discussion of Modern Concepts and its Relation to the Research in Poland.
- Author
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Dobiński, Wojciech
- Abstract
This paper describes the foundations of the periglacial concept beginning from the introduction of this term by Łoziński in 1909 and 1912. Its etymology along with the meaning and definitions that change over time are analysed in the present paper. Originally derived from geology, periglacial now functions as a geomorphological term. It has been compared with other terms used in the characterisation of cold geographical environments; the role of freezing and ice has been especially emphasised for periglaciology, and the most important types of ice have been highlighted. The present paper aims to show that with the increasing specialisation of research and the evolution of the meaning of the term periglacial, it is still seen as playing an important integrating role. The relation of the periglacial environment and ice to the glacial environment is also presented, showing the places of mutual overlapping of both environments. Old and newly introduced terms related to this concept such as periglacial facies, periglacial landscape, paraglacial, and cryo-conditioning are critically assessed. Finally, a short description of the permafrost in Poland, occurring in two remote and specific places, is presented: the active mountain permafrost covering the alpine belt of the Tatra Mountains about 1900 m a.s.l. and the relict permafrost in the Suwałki area, located in the northern lowland of Poland at a depth of 357 m and below. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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48. Segment Anything Model Can Not Segment Anything: Assessing AI Foundation Model's Generalizability in Permafrost Mapping.
- Author
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Li, Wenwen, Hsu, Chia-Yu, Wang, Sizhe, Yang, Yezhou, Lee, Hyunho, Liljedahl, Anna, Witharana, Chandi, Yang, Yili, Rogers, Brendan M., Arundel, Samantha T., Jones, Matthew B., McHenry, Kenton, and Solis, Patricia
- Subjects
LANGUAGE models ,BUILDING foundations ,ARTIFICIAL intelligence ,PERMAFROST ,GLOBAL warming ,TUNDRAS - Abstract
This paper assesses trending AI foundation models, especially emerging computer vision foundation models and their performance in natural landscape feature segmentation. While the term foundation model has quickly garnered interest from the geospatial domain, its definition remains vague. Hence, this paper will first introduce AI foundation models and their defining characteristics. Built upon the tremendous success achieved by Large Language Models (LLMs) as the foundation models for language tasks, this paper discusses the challenges of building foundation models for geospatial artificial intelligence (GeoAI) vision tasks. To evaluate the performance of large AI vision models, especially Meta's Segment Anything Model (SAM), we implemented different instance segmentation pipelines that minimize the changes to SAM to leverage its power as a foundation model. A series of prompt strategies were developed to test SAM's performance regarding its theoretical upper bound of predictive accuracy, zero-shot performance, and domain adaptability through fine-tuning. The analysis used two permafrost feature datasets, ice-wedge polygons and retrogressive thaw slumps because (1) these landform features are more challenging to segment than man-made features due to their complicated formation mechanisms, diverse forms, and vague boundaries; (2) their presence and changes are important indicators for Arctic warming and climate change. The results show that although promising, SAM still has room for improvement to support AI-augmented terrain mapping. The spatial and domain generalizability of this finding is further validated using a more general dataset EuroCrops for agricultural field mapping. Finally, we discuss future research directions that strengthen SAM's applicability in challenging geospatial domains. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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49. Foundations in Permafrost of Northern Canada: Review of Geotechnical Considerations in Current Practice and Design Examples.
- Author
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Dourado, João Batista de Oliveira Libório, Deng, Lijun, Chen, Yuxiang, and Chui, Ying-Hei
- Subjects
PERMAFROST ,GEOTECHNICAL engineering ,HOUSING ,SOIL mechanics ,STEEL pipe - Abstract
In northern Canada where permafrost is prevalent, a persistent shortage of accessible, affordable, and high-quality housing has been ongoing for decades. The design of foundations in permafrost presents unique engineering challenges due to permafrost soil mechanics and the effects of climate change. There is no specific design code for pile or shallow foundations in northern Canada. Consequently, the design process heavily relies on the experience of Arctic engineers. To clearly document the current practice and provide guidance to engineers or professionals, a comprehensive review of the practice in foundation design in the Arctic would be necessary. The main objective of this paper is to provide an overview of the common foundations in permafrost and the geotechnical considerations adopted for building on frozen soils. This study conducted a review of current practices in deep and shallow foundations used in northern Canada. The review summarized the current methods for estimating key factors, including the adfreeze strength, creep settlement, and frost heave, used in foundation design in permafrost. To understand the geotechnical considerations in foundation design, this study carried out interviews with several engineers or professionals experienced in designing foundations in permafrost; the findings and the interviewees' opinions were summarized. Lastly, in order to demonstrate the design methods obtained from the interviews and review, the paper presents two design examples where screw piles and steel pipe piles were designed to support a residential building in northern Canada, according to the current principles for adfreeze strength, long term creep settlement, and frost heave. The permafrost was assumed to be at −1.5 °C, and the design life span was assumed to be 50 years. The design examples suggested that for an axial load of 75 kN, a 12-m-long steel pipe pile or a 7-m-long screw pile would be needed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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50. Employing Automated Electrical Resistivity Tomography for detecting short- and long-term changes in permafrost and active layer dynamics in the Maritime Antarctic.
- Author
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Farzamian, Mohammad, Herring, Teddi, Vieira, Goncalo, Pablo, Miguel Angel de, Tabar, Borhan Yaghoobi, and Hauck, Christian
- Subjects
ELECTRICAL resistivity ,PERMAFROST ,CLIMATE extremes ,CRATER lakes ,SOIL horizons - Abstract
Repeated electrical resistivity tomography (ERT) surveys can substantially advance the understanding of spatial and temporal freeze-thaw dynamics in remote regions, such as Antarctica, where the evolution of permafrost has been poorly investigated. To enable the time-lapse ERT surveys in Antarctica, however, an automated ERT (A-ERT) system is required, as regular site visits are not feasible. In this context, we developed a robust A-ERT prototype and installed it in the Crater Lake CALM-S site at Deception Island, Antarctica to collect quasi-continuous ERT measurements. To efficiently process a large number of obtained A-ERT datasets, we developed an automated data processing workflow to efficiently filter and invert the A-ERT datasets and extract the key information required for a detailed investigation of permafrost and active layer dynamics. In this paper, we report on the results of two complete year-round A-ERT datasets collected in 2010 and 2019 at Crater Lake CALM-S site and compare them with available climate and borehole data. The A-ERT profile has a length of 9.5 m with an electrode spacing of 0.5 m, enabling a maximum investigation depth of approximately 2 m. Our detailed investigation of the A-ERT data and inverted modeling results shows that the A-ERT system can detect the active-layer freezing and thawing events with very high temporal resolution. The resistivity of the permafrost zone in 2019 is very similar to the values found in 2010, suggesting the stability of the permafrost over almost one decade at this site. The evolution of thaw depth exhibits also a similar pattern in both years, with the active layer thickness fluctuating between 0.20–0.35 m. However, a slight thinning of the active layer is evident in early 2019, compared to the equivalent period in 2010. These findings show that A-ERT, combined with the new processing workflow that we developed, is an efficient tool for studying permafrost and active layer dynamics with very high resolution and minimal environmental disturbance. The ability of the A-ERT setup to monitor the real-time progression of thaw depth, and to detect brief surficial refreezing and thawing of the active layer reveals the significance of the automatic ERT monitoring system to record continuous resistivity changes. This shows that the A-ERT setup described in this paper can be a significant addition to the Global Terrestrial Network for Permafrost (GTN-P) and the Circumpolar Active Layer Monitoring (CALM) networks to further investigate the impact of fast-changing climate and extreme meteorological events on the upper soil horizons and work towards establishing an early warning system for the consequences of climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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