CGRG Bibliography of Canadian Geomorphology
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Author : Eichler, H.
Date : 1981
Title : Gesteinstemperaturen und Insolationsverwitterung im hockarktischen Bereich, Oobloyah Bay, N-Ellesmere Island, N.W.T., Kanada = Rock temperatures and insolation weathering in the High Arctic, Oobloyah Bay, northern Ellesmere Island, N.W.T., Canada
Publication : Ergebnisse der Heidelberg-Ellesmere Island-Expedition = Results of the Heidelberg Ellesmere Island Expedition / Edited by Dietrich Barsen and Lorenz King. Heidelberger Geographische Arbeiten, Heft
Issue : 69:
Page(s) : 441-464
Abstract
Between June 25th and August 3rd, 1978 rock temperature measurements were executed in the expedition area at elevations up to 125 m a.s.l. This was accomplished in order to be able to estimate the importance of high arctic insolation relevant for weathering processes. During this time no zero degree transition could be recorded except for fluvioglacial gravel near the glacial margin of Carl Troll Glacier - but instead remarkably high surface maxima of rock temperatures up to 39,7 C. The constantly very low angle of sun radiation during all the high arctic summertime results in slopy terrain - especially in those parts exposed to the south - in areal shadow effects quite in contrast to the conditions in the plain. The consequence is an excessive thermic diurnal rhythm on shady "night slopes" and their block material resting on them. For this reason it is proposed here to distinguish between arctic "slope" and "plain" regions when discussing microclimatological questions or even thermic controlled weathering processes. Blocks of the arctic plain region do not show features of thermic strain being dependant on exposition because they are radiated more or less regularly the whole day round, however the blocks of an arctic slope region do show strain. In the latter case those sides of blocks which were enlighted only half a day long carry very strong weathering features especially where they are exposed to the south on south slopes. Absence of frost, high daily amplitudes of surface temperatures (up to 20 C) as well as heavy thermic turbulence in the rock's interior being expressed by the lines of tautochrones, all these oblige to a change of mind - at least as far as the expedition area is concerned. Not the frost but the insolation appears to be the main agent of high arctic temperature weathering. Especially in the high North exposition and slope angle hardly ever were taken into account as controlling factors of high geo-ecological and morphodynamic rank. An application of high arctic weathering rules upon Pleistocene environments of our temperature zones following the actualistic principle should be dealt with utmost precaution.
Bibliography of Canadian Geomorphology