Pingos and Pingo Scars: Their Characteristics, Distribution, and Utility in Reconstructing Former Permafrost Environments

Flemal, Ronald C.

doi:10.1016/0033-5894(76)90039-9

Cited by 46 publications

(28 citation statements)

References 30 publications

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“…The formation and presence of pingos is closely linked to past and present local climatological, geological, and hydrological conditions. Pingo growth and decay rates, pingo age, and past distribution of pingos have been used for palaeoenvironmental reconstructions in periglacial landscapes (Flemal, 1976;Mackay, 1986;Walker et al, 1996). In addition, sediments in pingos have also been used for palaeoenvironmental reconstructions (Hyvärinen and Ritchie, 1975;Grosse et al, 2007).…”

Section: Pingomentioning

confidence: 99%

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

Wetterich

Grosse

Schirrmeister

et al. 2012

Quaternary Science Reviews

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a b s t r a c tA terrestrial sediment sequence exposed in an eroding pingo provides insights into the late-Quaternary environmental history of the northern Seward Peninsula, Alaska. We have obtained the first radiocarbondated evidence for a mid-Wisconsin thermokarst lake, demonstrating that complex landscape dynamics involving cyclic permafrost aggradation and thermokarst lake formation occurred over stadiale interstadial as well as glacialeinterglacial time periods. High values of Picea pollen and the presence of Larix pollen in sediments dated to 50e40 ka BP strongly suggest the presence of forest or woodland early in MIS 3; the trees grew within a vegetation matrix dominated by grass and sedge, and there is indirect evidence of grazing animals. Thus the interstadial ecosystem was different in structure and composition from the Holocene or from the preceding Last Interglacial period. An early Holocene warm period is indicated by renewed thermokarst lake formation and a range of fossil taxa. Multiple extralimital plant taxa suggest mean July temperatures above modern values. The local presence of spruce during the early Holocene warm interval is evident from a radiocarbon-dated spruce macrofossil remain and indicates significant range extension far beyond the modern tree line. The first direct evidence of spruce in Northwest Alaska during the early Holocene has implications for the presence of forest refugia in Central Beringia and previously assumed routes and timing of post-glacial forest expansion in Alaska.

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Section: Pingomentioning

confidence: 99%

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

Wetterich

Grosse

Schirrmeister

et al. 2012

Quaternary Science Reviews

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“…For the most part, the ponds are situated in arable agricultural land and have their origins as 'marl pits' being formed by marl extraction largely in the eighteenth-nineteenth centuries (Prince 1964). Other ponds have their origins as pingos formed at the end of the Last Glaciation 12.7-11.5 cal kyr BP (Flemel 1976). The ponds were all small (\ 40 m max.…”

Section: Study Sitesmentioning

confidence: 99%

Mission possible: diatoms can be used to infer past duckweed (lemnoid Araceae) dominance in ponds

et al. 2017

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Compared to larger lakes, ponds have rarely been the focus of palaeoecological studies. A common feature of ponds, especially those subject to eutrophication, is mass surface coverings of lemnoid Araceae (duckweed) which have severe implications for ecological processes in small waterbodies, in particular lowered oxygen content. To help understand the implications of duckweed dominance for the longterm ecology of ponds, and to determine the potential for palaeoecological studies in ponds more generally, we develop a new diatom-based Lemna-indicator metric. Recent studies of diatom host-plant relationships have shown significant associations between duckweed and the epiphytes Lemnicola hungarica and Sellaphora saugerresii (formally known as Sellaphora seminulum). To determine the potential of these species as palaeo-indicators of long-term duckweed dynamics in ponds, we investigated the diatom composition of surface sediment assemblages in sets of duckweed and non-duckweed-dominated ponds in Norfolk, eastern England. In addition, we undertook diatom analysis of two cores from a small farmland pond (Bodham Rail Pit) subject to a known duckweed dominance event (1999)(2000)(2001)(2002)(2003)(2004)(2005). Both L. hungarica and S. saugerresii were significant predictors of past Lemna dominance in the surface sediments. Further, in the core study, both diatom species accurately and closely tracked the documented ''on-off'' duckweed cycle. Our study suggests huge potential for using ponds in palaeoecological studies and for diatombased investigations of floating plant histories.

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“…Parmi ces dernières, certaines comme les palses tourbeuses sont souvent entièrement détruites lors de la disparition du pergélisol et deviennent ainsi inutilisables pour reconstituer les paléoclimats froids ou les paléotempératures du sol. De l'avis général, les indicateurs les plus sûrs demeurent les pingos (FLEMAL, 1976), les réseaux polygonaux à fentes de glace (BLACK, 1976b, SVENSSON, 1978, les terrasses de cryoplanation (REGER et PÉWÉ, 1976) et les formes d'éjection rocheuse (DIONNE, 1983). D'autres formes et phénomènes périglaciaires comme les géli-sols avec triage (GOLDTHWAIT, 1976) la gélifluxion (BENEDICT, 1976), les glaciers rocheux (WHITE, 1976) les palses minérales (PAYETTE et SEGUIN, 1979;LAGAREC, 1982) Les connaissances sur les variations climatiques au Québec et en particulier au Québec méridional, depuis la dernière glaciation, demeurent fort limitées 1 .…”

Section: Introductionunclassified

Réseaux reliques de polygones de tourbe, moyenne et basse Côte-Nord du Saint-Laurent, Québec

Dionne¹

2007

gpq

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RÉSUMÉ Sur la moyenne et la basse Côte Nord du Saint-Laurent, notamment à Blanc-Sablon, île Verte et île Nue de Mingan, existent des réseaux de polygones dans des tapis tourbeux de moins de 100 cm d'épaisseur recouvrant des plages sableuses ou caillouteuses de la mer de Goldthwait entre 4 et 8 m d'altitude. À l'île Verte, les polygones mesurent entre 4 et 17 m de côté et sont séparés par des fissures béantes larges de 25 à 100 cm et jusqu'à 190 cm aux intersections, et profondes de 75 à 90 cm. La tourbe sèche, compacte et ligneuse, est composée de deux espèces dominantes, Empetrum nigrum et Ledum groenlandicum. La température moyenne annuelle de l'air est d'environ 0,50C et il n'existe pas de pergélisol. Il s'agit de polygones de tourbe reliques présentant les mêmes caractéristiques que ceux des zones de pergélisol continu, notamment dans la région de Churchill (Manitoba), sur la côte ouest de la mer d'Hudson. Des diverses hypothèses évoquées pour expliquer l'origine des fissures, celle impliquant une contraction par le froid avec formation de coins de glace est retenue. Les datations au 140C obtenues sur la base du tapis organique indiquent un âge inférieur à 2000 ans en accord avec l'âge d'émersion des niveaux de 4 à 8 m dans le golfe du Saint-Laurent. La matière organique tapissant le fond des fissures béantes a donné un âge plus récent que 500 ans. En conséquence, ce réseau s'est développé au cours du dernier millénaire et probablement au cours du Petit Âge glaciaire. Il témoigne de l'existence ancienne de pergélisol dans l'est du Québec et implique des températures moyennes annuelles de l'air de l'ordre de -40C ou moins. Il met en évidence une fluctuation climatique relativement importante à une époque historique, fluctuation climatique retracée d'ailleurs dans d'autres régions du Québec nordique et les hauts sommets de la Gaspésie.

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Pingos and Pingo Scars: Their Characteristics, Distribution, and Utility in Reconstructing Former Permafrost Environments

Cited by 46 publications

References 30 publications

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

Late Quaternary environmental and landscape dynamics revealed by a pingo sequence on the northern Seward Peninsula, Alaska

Mission possible: diatoms can be used to infer past duckweed (lemnoid Araceae) dominance in ponds

Réseaux reliques de polygones de tourbe, moyenne et basse Côte-Nord du Saint-Laurent, Québec

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