Document generated on 09/27/2021 5:54 a.m. Géographie physique et Quaternaire Permafrost spatial and temporal variations near Schefferville, Nouveau-Québec Les variations spatio-temporelles du pergélisol à Schefferville, Nouveau-Québec Räumliche und zeitliche Variationen des Dauerfrostes bei Schefferville, Nouveau-Québec Frank H. Nicholson Le pergélisol au Québec — Labrador Article abstract Volume 33, Number 3-4, 1979 Specially detailed studies of permafrost have developed at Schefferville because of the availability of long term data and the economic stimulus of the URI: https://id.erudit.org/iderudit/1000363ar effect of permafrost on the iron mines. Knowledge of the three dimensional DOI: https://doi.org/10.7202/1000363ar distribution of permafrost has been greatly expanded and energy budget studies have given confidence to many aspects of interpretation. Although the See table of contents mean annual temperatures are -5 to -6.5°, large areas remain free of permafrost due to the winter insulation provided by deep snow which accumulates where snow drifting is subdued (e.g. in woodland). There are large year to year variations of frozen ground temperature in the upper 25 m Publisher(s) (due to variations of snow conditions) and active layer depth (related to Les Presses de l’Université de Montréal variations of summer weather conditions). Suprapermafrost groundwater movement is often concentrated along specific channels and transported heat causes very deep active layers (up to 12 m) or even maintains unfrozen zones ISSN (up to 30 m). On simple sites the active layer is primarily related to % 0705-7199 (print) vegetation cover, with mean depth ranging from 2.3 m under 100% vegetation 1492-143X (digital) to 3.6 m under bare ground. Considerable effort has been devoted to quantifying snow data for permafrost prediction and good results have been Explore this journal obtained from quanti-titavely relating ground temperatures to snow and a simulated groundwater measure. The permafrost is generally in balance with the present climate and new permafrost has developed in mine waste dumps. Cite this article Nicholson, F. H. (1979). Permafrost spatial and temporal variations near Schefferville, Nouveau-Québec. Géographie physique et Quaternaire, 33(3-4), 265–277. https://doi.org/10.7202/1000363ar Tous droits réservés © Les Presses de l’Université de Montréal, 1979 This document is protected by copyright law. Use of the services of Érudit (including reproduction) is subject to its terms and conditions, which can be viewed online. https://apropos.erudit.org/en/users/policy-on-use/ This article is disseminated and preserved by Érudit. Érudit is a non-profit inter-university consortium of the Université de Montréal, Université Laval, and the Université du Québec à Montréal. Its mission is to promote and disseminate research. https://www.erudit.org/en/ Géogr. phys. Quat, 1979, vol. XXXIII, nos3.4 , p. 265-277. PERMAFROST SPATIAL AND TEMPORAL VARIATIONS NEAR SCHEFFERVILLE, NOUVEAU-QUÉBEC Frank H. NICHOLSON, Geography Department, City of Liverpool College of Higher Education, Prescot, Mersey- side L34 1NP, England. ABSTRACT Specially detailed studies RÉSUMÉ Les variations spatio-tem­ ZUSAMMENFASSUNG Ràumliche und of permafrost have developed at Schef­ porelles du pergélisol à Schefferville, zeitliche Variationen des Dauerfrostes ferville because of the availability of Nouveau-Québec On a pu entrepren­ bei Schefferville, Nouveau-Québec. Ein- long term data and the economic stim­ dre, dans cette région, des études par­ gehende Forschungen des Dauerfrostes ulus of the effect of permafrost on the ticulièrement détaillées grâce à l'exis­ haben sich in Schefferville auf Grund iron mines. Knowledge of the three tence de données sur une longue pério­ der Verfùgbarkei t von « lon g term »Date n dimensional distribution of permafrost de et de l'importance de ces études und des wirtschaftlichen Anreizes, den has been greatly expanded and energy sur les mines de fer. Les connaissances die Folgen des Dauerfrostes auf die budget studies have given confidence to sur la répartition tri-dimensionnelle du Eisenminen haben, entwickelt. Die many aspects of interpretation. Although pergélisol se sont grandement accrues, Kentnisse der dreidimensionellen Ver­ the mean annual temperatures are -5 et les études du bilan thermique ont teilung des Dauerfrostes haben sich to -6.5°, large areas remain free of permis une meilleure interprétation gé­ sehr verbreitet, und Studien des Energie- permafrost due to the winter insulation nérale des données. Malgré une tem­ budgets haben sich auf viele Aspekte provided by deep snow which accumu­ pérature moyenne annuelle de -5 à der Interpretation verlassen. Obgleich lates where snow drifting is subdued -6,5° C, de vastes espaces demeurent die jâhrlichen Mitteltemperaturen bei (e.g. in woodland). There are large year non pergélisolés grâce au pouvoir iso­ -5 bis -6,5°C liegen, bleiben grosse to year variations of frozen ground lant de la neige (dans les boisés notam­ Gebiete auf Grund der Winterisolation temperature in the upper 25 m (due to ment). La température du sol varie consi­ der dicken Schneedecke, die sich dort variations of snow conditions) and active dérablement dans les 25 premiers mè­ ansammelt wo Schneetreiben verhin- layer depth (related to variations of tres (suivant l'épaisseur du couvert nival) dert ist (Waldland) dauerfrostfrei. Die summer weather conditions). Supra­ ainsi que l'épaisseur du mollisol (sui­ Bodenfrosttemperaturen der oberen permafrost groundwater movement is vant les températures estivales). La cir­ 25 m, (auf Grund der Variationen der often concentrated along specific chan­ culation de l'eau souterraine se fait Schneeverhàltnisse) sowie die Tiefe der nels and transported heat causes very le long de canaux particuliers, et le Auftauzone (von den sommerlichen Wet- deep active layers (up to 12 m) or even transfert de chaleur ainsi provoqué terverhâltnissen abhàngig) zeigen grosse maintains unfrozen zones (up to 30 m). permet le développement d'épaisseurs jàhrliche Verànderungen. Superdauer- On simple sites the active layer is pri­ considérables de mollisol (jusqu'à 12 m) frost-Grundwasser-Bewegungen sind marily related to % vegetation cover, et même de taliks (jusqu'à 30 m). Dans oft um spezifische Kanàle konzentriert with mean depth ranging from 2.3 m les sites, où il n'y a pas de circulation und transportierte Wàrme verursacht under 100% vegetation to 3.6 m under souterraine, l'épaisseur du mollisol sehr tiefe Auftauzonen (bis zu 12 m) oder bare ground. Considerable effort has dépend de la densité du couvert végé­ erhàlt sogar ungefrorene Zonen (bis been devoted to quantifying snow data tal, l'épaisseur moyenne étant de 2,3 m zu 30 m). In einfachen Gebieten ist die for permafrost prediction and good lorsque la couverture est totale et de Auftauzone hauptsàchlich in Verbin- results have been obtained from quanti- 3,6 m sous un sol dénudé. Beaucoup dung mit dem % satz der Vegetations­ titavely relating ground temperatures to d'efforts ont été consacrés à la quanti­ decke, mit durchschnittlicher Tiefe von snow and a simulated groundwater fication des données afin d'en arriver à 2.3 m bei 100% Vegetation und 3.6 m measure. The permafrost is generally in une meilleure interprétation des caracté­ unter kahlem Boden. Betràchtliche Be- balance with the present climate and ristiques du pergélisol; les résultats muhungen wurden gemacht, die Schnee- new permafrost has developed in mine obtenus sont intéressants. On en conclut mengen einzuschàtzen, um Dauerfrost- waste dumps. que le pergélisol est habituellement vorhersagen machen zu konnen, und en équilibre avec le climat actuel. gute Resultate wurden durch Mengen- vergleiche zwischen Bodentemperatur und Schnee und einer simulierten Grundwassermessung erreicht. 266 F. H. NICHOLSON INTRODUCTION centage of the terrain and there is widespread perma­ frost (see Fig. 1). The generalised permafrost distribu­ The presence of widespread permafrost in the Schef­ tion in the Québec-Labrador Peninsula was first clearly ferville area was not obvious without detailed study. explained in these terms by IVES (1960, 1961, 1962), In consequence when the decision was made to open and BROWN (1975) has published other broad scale the iron mines of the Schefferville area permafrost was information on the permafrost distribution. not taken into account (IVES, 1962). Palsas are the only definite surface indication of permafrost conditions and these are very restricted in their distribution. Cer­ VISUAL CHARACTER AND PHYSICAL tainly they do not indicate the widespread permafrost PROPERTIES OF THE PERMAFROST which caused severe problems in some mines and stimulated a series of studies in the fifties and sixties The characteristics of the frozen ground can be (BONNLANDER, 1958; IVES, 1960, 1961, 1962; BONN- examined in mines immediately after a mine blast. The LANDER and MAJOR-MAROTHY, 1964; ANNERSTEN, amount of ice and its distribution varies very widely 1964, 1966; THOM 1969). These studies were especially with the materials. Unaltered iron formation is predom­ valuable because of the availability of exploration drill inantly chert with variable iron content (taconite), but holes up to 100 m deep for temperature observations the soft iron ores of the Schefferville area were formed and also because of the economic stimulus to maintain by leaching of the primary iron formation which reduced observations over a relatively long period. Based on the silica content and increased