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Kenji Yoshikawa - One of the best experts on this subject based on the ideXlab platform.
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Stable isotopes in the closed-system Weather Pingo, Alaska and Pestsovoye Pingo, northwestern Siberia
Cold Regions Science and Technology, 2016Co-Authors: Yurij K Vasil'chuk, Kenji Yoshikawa, Daniel E. Lawson, Nadine A Budantseva, Julia N Chizhova, Yevgeni Ye. Podborny, Alla Constantinovna Vasil'chukAbstract:Abstract High-resolution records of the stable isotopic (δ 18 O and δD) composition of ice within two closed system (hydrostatic) Pingos indicate a complex history of ice formation by segregation and injection and Pingo growth. Physical properties and internal structure of continuous ice cores in the center of the Weather Pingo near Prudhoe Bay, Alaska, and the Pestsovoye Pingo, in northwestern Siberia, were described and then sub-sampled for analysis of the isotopic composition. Changes in the isotopic signature and physical properties of ice with depth reveal distinct patterns in both Pingos indicative of ice growth as permafrost aggraded into the drained lake basin. In the initial stages following active layer deepening and initial freeze back, in-situ water migrating toward the freezing front froze at a relatively rapid rate as revealed by a complex isotopic record and small ice crystal size in the cores of Weather Pingo. Once the water supply became limited, freezing under equilibrium conditions resulted in an isotopic composition consistent with Rayleigh-type fractionation and δ 18 O and δD values that become more negative with depth. The data for the Pestsovoye Pingo reveal similar trends related to the initial stages of water migration and freezing, followed by isotopic fractionation under equilibrium conditions as unfrozen water available in the talik beneath the Pingo became limited. Most of the ice in both Pingos (~ 50%) formed during this final stage of permafrost aggradation. Thus temporal variability in water migration and freezing rate at the base of each Pingo created a complex isotopic stratigraphy and ice growth history.
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Groundwater Hydrology and Stable Isotope Analysis of an Open-System Pingo in Northwestern Mongolia
Permafrost and Periglacial Processes, 2013Co-Authors: Kenji Yoshikawa, N. Sharkhuu, Anarmaa SharkhuuAbstract:The first record of stable isotopes through a complete sequence of ice within an open-system Pingo in northwestern Mongolia indicates a complex history of ice formation and Pingo growth. A continuous section of ice 32 m long was cored through the centre of Mongot Pingo, and ice cores were analysed for stable isotopes and chemical composition. Two different stable isotope patterns in separate ice sections are identified: 1 open-system freezing and 2 semi-closed system (or closed system) freezing. Discharge measurements were observed in 2009 after drilling through Pingo ice to artesian sub-Pingo water and compared with data collected from the same Pingo in 1968. Approximately 850–950 m3 of sub-Pingo water discharged within 120 h during drilling in both 1968 and 2009, a volume equivalent to about 10 per cent of the current Pingo ice volume. Between 1968 and 2009, permafrost (Pingo ice) thickened by about 60 cm (1.46 cm per year), from 32.0 to 32.6 m, due to the decrease in sub-Pingo artesian water pressure after water release from the 1968 drilling. The major mechanism for ice formation at this Pingo is groundwater artesian pressure, though not continuously. Four major stages of Pingo growth after 8790 yr BP are inferred. Copyright © 2013 John Wiley & Sons, Ltd.
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Pingos on Earth and Mars
Planetary and Space Science, 2008Co-Authors: Devon M. Burr, Kenneth L. Tanaka, Kenji YoshikawaAbstract:Abstract Pingos are massive ice-cored mounds that develop through pressurized groundwater flow mechanisms. Pingos and their collapsed forms are found in periglacial and paleoperiglacial terrains on Earth, and have been hypothesized for a wide variety of locations on Mars. This literature review of Pingos on Earth and Mars first summarizes the morphology of terrestrial Pingos and their geologic contexts. That information is then used to asses hypothesized Pingos on Mars. Pingo-like forms (PLFs) in Utopia Planitia are the most viable candidates for Pingos or collapsed Pingos. Other PLFs hypothesized in the literature to be Pingos may be better explained with other mechanisms than those associated with terrestrial-style Pingos.
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Pingo growth ages in the delta area, Adventdalen, Spitsbergen
Polar Record, 1996Co-Authors: Kenji Yoshikawa, Toshio NakamuraAbstract:ABSTRACTThe open-system Pingos of Spitsbergen are formed outside terminal moraines, fault zones, and delta areas. Pingos in this study area were located near the shore in active geologic uplift areas. Three open-system Pingos in the Adventdalen delta area of Spitsbergen were examined. Pingos closer to shore are younger in age and those farther away are older. Growth of these Pingos occurs rapidly after initial submarine uplift and a minimum thickness of permafrost is established. Hut Pingo, which is farthest from the sea, was formed after 6980±70 a BP (NUTA-3856). Driftwood associated with Longyear Pingo, in the middle part of the delta, was dated at 2800±90 a BP. The radiocarbon age of peat near the shore Pingo, Lagoon Pingo, was 140±20 a BP. The growth of the Pingos is related to transgression and development of permafrost.
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Growth and Collapse History of Pingos, Kuganguaq, Disko Island, Greenland
1996Co-Authors: Kenji Yoshikawa, Toshio Nakamura, Yaeko IgarashiAbstract:The growth anel collapse history of two Pingos located approximately 18 m a.s.l, anel 35 m a.s.1. in Kuganguag, Disko lsland, west-central Greenland were examined. The Pingos of this area were formed on Tertiary basalt rocks. One of the Pingos is located in the middle of an alluvial fan, the other is on a ri ver bed. Both have already collapsed. The Pingo on the river bed had already collapsed at least 3545±60 year BP ('"C dating frorn base of the pond sediments in the Pingo crater). Both Pingos forrned after the sea's retreat as permafrost developed in the newly exposed delta bottom. Zusammenfassung: Bildung und Zerfall zweier Pingos, ungefahr 18 m bzw. 35 m Uber dem Meeresspiegel in Kuganguag, Disko lsland, westliches Mittel gronland werden beschrieben Die Pingos von Disko Island bildeten sich Uber tertiaren Vulkaniten. Einer der Pingos liegt auf einem alluvialen Sedimentfacher. der andere liegt in einem Flusbett; beide sind bereits seit langem zerfallen. Der Zerfall des Flus-Pingo erfolgte vor mindestens 3540+60 Jahren ("C-Datierung der Seesedimente im Pingokrater). Beicle Pingos bildeten sich nach dem Absin ken des Meeresspiegels als sich Permafrost-Beclingungen in dem aufgetauch ten Deltabereich bildeten.
Christopher R. Burn - One of the best experts on this subject based on the ideXlab platform.
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a century 1910 2008 of change in a collapsing Pingo parry peninsula western arctic coast canada
Permafrost and Periglacial Processes, 2011Co-Authors: J. R. Mackay, Christopher R. BurnAbstract:An isolated, eroding Pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the Pingo crater pond has drained, the north side of the Pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15–17 m). The erosion of the Pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the Pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the Pingo. It is unusual to detect change of collapsed Pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the Pingo. The increases since 1996 in height and cover of willows are the first record of such change from western Arctic Canada. Copyright © 2011 John Wiley & Sons, Ltd.
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A Century (1910–2008) of Change in a Collapsing Pingo, Parry Peninsula, Western Arctic Coast, Canada
Permafrost and Periglacial Processes, 2011Co-Authors: J. R. Mackay, Christopher R. BurnAbstract:An isolated, eroding Pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the Pingo crater pond has drained, the north side of the Pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15–17 m). The erosion of the Pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the Pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the Pingo. It is unusual to detect change of collapsed Pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the Pingo. The increases since 1996 in height and cover of willows are the first record of such change from western Arctic Canada. Copyright © 2011 John Wiley & Sons, Ltd.
Benjamin M. Jones - One of the best experts on this subject based on the ideXlab platform.
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Assessment of Pingo distribution and morphometry using an IfSAR derived digital surface model, western Arctic Coastal Plain, Northern Alaska
Geomorphology, 2012Co-Authors: Benjamin M. Jones, Guido Grosse, Kenneth M. Hinkel, Christopher D. Arp, Shane Walker, Richard A. Beck, John P. GallowayAbstract:Abstract Pingos are circular to elongate ice-cored mounds that form by injection and freezing of pressurized water in near-surface permafrost. Here we use a digital surface model (DSM) derived from an airborne Interferometric Synthetic Aperture Radar (IfSAR) system to assess the distribution and morphometry of Pingos within a 40,000 km2 area on the western Arctic Coastal Plain of northern Alaska. We have identified 1247 Pingo forms in the study region, ranging in height from 2 to 21 m, with a mean height of 4.6 m. Pingos in this region are of hydrostatic origin, with 98% located within 995 drained lake basins, most of which are underlain by thick eolian sand deposits. The highest Pingo density (0.18 km− 2) occurs where streams have reworked these deposits. Morphometric analyses indicate that most Pingos are small to medium in size (
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Spatial distribution of Pingos in northern Asia
The Cryosphere, 2011Co-Authors: Guido Grosse, Benjamin M. JonesAbstract:Abstract. Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of 6059 Pingo locations in a 3.5×106 km2 region of northern Asia was assembled from topographic maps. A first order analysis was carried out with respect to permafrost, landscape characteristics, surface geology, hydrology, climate, and elevation datasets using a Geographic Information System (GIS). Pingo heights in the dataset vary between 2 and 37 m, with a mean height of 4.8 m. About 64% of the Pingos occur in continuous permafrost with high ice content and thick sediments; another 19% in continuous permafrost with moderate ice content and thick sediments. The majority of these Pingos are likely hydrostatic Pingos, which are typical of those located in drained thermokarst lake basins of northern lowlands with continuous permafrost. About 82% of the Pingos are located in the tundra bioclimatic zone. Most Pingos in the dataset are located in regions with mean annual ground temperatures between −3 and −11 °C and mean annual air temperatures between −7 and −18 °C. The dataset confirms that surface geology and hydrology are key factors for Pingo formation and occurrence. Based on model predictions for near-future permafrost distribution, about 2073 Pingos (34%) along the southern margins of permafrost will be located in regions with thawing permafrost by 2100, which ultimately may lead to increased occurrence of Pingo collapse. Based on our dataset and previously published estimates of Pingo numbers from other regions, we conclude that there are more than 11 000 Pingos on Earth.
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Spatial distribution of Pingos in Northern Asia
The Cryosphere Discussions, 2010Co-Authors: Guido Grosse, Benjamin M. JonesAbstract:Abstract. Pingos are prominent periglacial landforms in vast regions of the Arctic and Subarctic. They are indicators of modern and past conditions of permafrost, surface geology, hydrology and climate. A first version of a detailed spatial geodatabase of more than 6000 Pingo locations in a 3.5 × 106 km2 region of Northern Asia was assembled from topographic maps. A first order analysis was carried out with respect to permafrost, landscape characteristics, surface geology, hydrology, climate, and elevation datasets using a Geographic Information System (GIS). Pingo heights in the dataset vary between 2 and 37 m, with a mean height of 4.8 m. About 64% of the Pingos occur in continuous permafrost with high ice content and thick sediments; another 19% in continuous permafrost with moderate ice content and thick sediments. The majority of these Pingos likely formed through closed system freezing, typical of those located in drained thermokarst lake basins of northern lowlands with continuous permafrost. About 82% of the Pingos are located in the tundra bioclimatic zone. Most Pingos in the dataset are located in regions with mean annual ground temperatures between −3 and −11 °C and mean annual air temperatures between −7 and −18 °C. The dataset confirms that surface geology and hydrology are key factors for Pingo formation and occurrence. Based on model predictions for near-future permafrost distribution, hundreds of Pingos along the southern margins of permafrost will be located in regions with thawing permafrost by 2100, which ultimately may lead to increased occurrence of Pingo collapse. Based on our dataset and previously published estimates of Pingo numbers from other regions, we conclude that there are more than 11 000 Pingos on Earth.
J. R. Mackay - One of the best experts on this subject based on the ideXlab platform.
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a century 1910 2008 of change in a collapsing Pingo parry peninsula western arctic coast canada
Permafrost and Periglacial Processes, 2011Co-Authors: J. R. Mackay, Christopher R. BurnAbstract:An isolated, eroding Pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the Pingo crater pond has drained, the north side of the Pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15–17 m). The erosion of the Pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the Pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the Pingo. It is unusual to detect change of collapsed Pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the Pingo. The increases since 1996 in height and cover of willows are the first record of such change from western Arctic Canada. Copyright © 2011 John Wiley & Sons, Ltd.
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A Century (1910–2008) of Change in a Collapsing Pingo, Parry Peninsula, Western Arctic Coast, Canada
Permafrost and Periglacial Processes, 2011Co-Authors: J. R. Mackay, Christopher R. BurnAbstract:An isolated, eroding Pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the Pingo crater pond has drained, the north side of the Pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15–17 m). The erosion of the Pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the Pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the Pingo. It is unusual to detect change of collapsed Pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the Pingo. The increases since 1996 in height and cover of willows are the first record of such change from western Arctic Canada. Copyright © 2011 John Wiley & Sons, Ltd.
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Electrical freezing potentials measured in a Pingo growing in the western Canadian Arctic
Cold Regions Science and Technology, 1996Co-Authors: V. R. Parameswaran, J. R. MackayAbstract:A probe containing copper electrodes, thermocouples, and a soil salinity sensor assembly with calibrated thermistors, was installed in a vertical drill hole at the top of a Pingo located about 20 km southwest of Tuktoyaktuk, Northwest Territories. The electrodes were positioned both in the Pingo ice at the top and in the underlying water lens. The salinity sensors were in the water lens. Measurements of electrical potentials developed on different electrodes in succeeding years after installation showed a sharp decrease in the potential at the electrode located at or near the freezing interface between the ice and water, when compared to that developed on the other electrodes. The magnitude of the freezing potentials measured were in the range of -50 to -100 mV (in one year up to 174 mV). The present field experiment showed that electrical potential probes can detect the progress of the freezing front between ice and water under natural conditions when the freezing rate is extremely slow. The average rate of advancement of the freezing front between the ice and water lens within the Pingo was 15 cm per year.
P. Voinchet - One of the best experts on this subject based on the ideXlab platform.
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Seismically induced shale diapirism: the Mine d’Or section, Vilaine estuary, Southern Brittany
International Journal of Earth Sciences, 2009Co-Authors: B. Vliet-lanoe, C. Hibsch, L. Csontos, S. Jegouzo, B. Hallégouët, M. Laurent, A. Maygari, D. Mercier, P. VoinchetAbstract:The Pénestin section (southern Brittany) presents large regular undulations, commonly interpreted as evidence of periglacial Pingos. It is an upper Neogene palaeoestuary of the Vilaine River reactivated during the middle Quaternary (middle terrace). It is incised into a thick kaolinitic saprolite and deformed by saprolite diapirs. This paper presents the arguments leading to a mechanistic interpretation of the deformations at Pénestin. Neither recent transpressive tectonics nor diagnostic evidence of periglacial Pingo have been found despite evidence for a late paleo-permafrost. The major deformational process is shale diapirism, initially triggered by co-seismic water supply, with further loading and lateral spreading on an already deformed and deeply weathered basement, which allowed the shale diapirism to develop. Deformations are favoured by the liquefaction of the saprolite and a seaward mass movement and recorded, rather distant, effects of an earthquake (c. 280 ka B.P.) resulting from the progressive subsidence of the southern Armorican margin. These deformations triggered by an earthquake are similar to those induced by classical shale diapirism. They are probably common in tectonically active continental environments with shallow water table.
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Seismically induced shale diapirism : the Mine d'Or section, Vilaine estuary, Southern Brittany
International Journal of Earth Sciences, 2009Co-Authors: Brigitte Van Vliet-lanoë, C. Hibsch, L. Csontos, S. Jegouzo, B. Hallégouët, M. Laurent, A. Maygari, D. Mercier, P. VoinchetAbstract:The Pénestin section (southern Brittany) presents large regular undulations, commonly interpreted as evidence of periglacial Pingos. It is an upper Neogene palaeoestuary of the Vilaine River reactivated during the middle Quaternary (middle terrace). It is incised into a thick kaolinitic saprolite and deformed by saprolite diapirs. This paper presents the arguments leading to a mechanistic interpretation of the deformations at Pénestin. Neither recent transpressive tectonics nor diagnostic evidence of periglacial Pingo have been found despite evidence for a late paleo-permafrost. The major deformational process is shale diapirism, initially triggered by co-seismic water supply, with further loading and lateral spreading on an already deformed and deeply weathered basement, which allowed the shale diapirism to develop. Deformations are favoured by the liquefaction of the saprolite and a seaward mass movement and recorded, rather distant, effects of an earthquake (c. 280 ka B.P.) resulting from the progressive subsidence of the southern Armorican margin. These deformations triggered by an earthquake are similar to those induced by classical shale diapirism. They are probably common in tectonically active continental environments with shallow water table.