431 resultados para heronian mean


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The Laurichard active rock glacier is the permafrost-related landform with the longest record of monitoring in France, including an annual geodetic survey, repeated geoelectrical campaigns from 1979 onwards and continuous recording of ground temperature since 2003. These data were used to examine changes in creep rates and internal structure from 1986 to 2006. The control that climatic variables exert on rock glacier kinematics was investigated over three time scales. Between the 1980s and the early 2000s, the main observed changes were a general increase in surface velocity and a decrease in internal resistivity. At a multi-year scale, the high correlation between surface movement and snow thickness in the preceding December appears to confirm the importance of snow cover conditions in early winter through their influence on the ground thermal regime. A comparison of surface velocities, regional climatic datasets and ground sub-surface temperatures over six years suggests a strong relation between rock glacier deformation and ground temperature, as well as a role for liquid water due to melt of thick snow cover. Finally, unusual surface lowering that accompanied peak velocities in 2004 may be due to a general thaw of the top of the permafrost, probably caused both by two successive snowy winters and by high energy inputs during the warm summer of 2003.

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Über die klimatischen Verhältnisse des Nordostlandes allgemein gültige Aussagen zu machen, dazu sind wir nach den vorhandenen Unterlagen noch nicht in der Lage. Denn diese Unterlagen beschränken sich auf die wenigen Aufzeichnungen der bisherigen Expeditionen (30), von denen nur die Oxford-Expedition 1935/36 über einen ganzen Jahresverlauf von Messungen an einer Stelle, im Branntwein-Fjord, und von Parallelbeobachtungen von der Dauer einiger Wochen bis mehrerer Monate an anderen Stellen verfügt. Erst wenn die Beobachtungen und Messungen der Expedition "Haudegen" im inneren Rijp-Fjord, besonders auch die Radiosondenaufstiege und die Höhenwindmessungen, dazu die mehrwöchigen Parallelbeobachtungen auf Schlittenreisen und in den Depots im Wahlenberg-Fiord und in der inneren Duve-Bucht ausgewertet sein werden, können wir abgerundetere Tatsachen über das Klima und den Witterungsverlauf im NordostIande erwarten.