Pleistocenni permafrost na uzemi Ceskoslovenska (Permafrost pléistocène en Tchécoslovaquie)
Climat historique ; Géographie de l'Europe ; Permafrost ; Pléistocène ; Périglaciaire ; Quaternaire zones moyennes ; Tchécoslovaquie
Permafrost existed as early as the Early Pleistocene. An attempt has been made to calculate its thickness at the basis of computer technique in the Upper Pleniglacial. - (MS)
The evolution of the techniques, recent research, and the current model of local permafrost distribution are described, together with the characteristics of the Schefferville environment of particular relevance to local permafrost distribution
. Contents of the Schefferville permafrost database are described and some preliminary examples are given concerning outputs from a new Geographic Permafrost Information System.
Permafrost thickness and distribution in Finnish Lapland - Results of geoelectrical soundings
Finlande ; Géographie de l'Europe ; Lapland ; Permafrost ; Périglaciaire ; Sondage géoélectrique ; Zone froide
Geoelectrical soundings were carried out in 29 different places in order to find permafrost and to measure its thickness. In most places above timber line a permafrost thickness of 10-50 m was recorded. Permafrost was found at sites with thin snow
cover during winter. Here, deflation phenomena on the summits of fjells indicate the occurrence of permafrost. Vegetation type might be a good indicator of permafrost, too. It seems obvious that permafrost exists extensively on fjell summits of northern
Degradation of permafrost in the Xing'anling Mountains, Northeastern China
China ; Climatic warming ; Cold area ; Deforestation ; Degradation ; Mountain ; North-Eastern China ; Periglacial features ; Permafrost
This paper reviews the evidence and reasons for permafrost degradation, and offers a preliminary assessment of the present status and the future trends of permafrost conditions within the Xing'anling Mountains. Climate warming and deforestation have
led to permafrost degradation as shown by deepening of the active layer, thinning permafrost, rising ground temperatures, expanding taliks and the disappearance of permafrost patches. The present position of the southern limit of permafrost
Les études de terrain montrent que le permafrost est très répandu dans la haute montagne scandinave. Des zones de permafrost sont définies selon la continuité du phénomène.
Dans la grotte de Remouchamps (B), des dépôts meubles possèdent des traces indiscutables de glace de ségrégation, confirmant la présence d'un permafrost profond au cours de la dernière glaciation quaternaire. - (RS)
Canada ; Cartographie thématique ; Généralités sur la géographie ; Permafrost ; Périglaciaire ; Zone froide
Considérations sur la manière dont les cartes du permafrost ont été compilées et sur la nature des sources statistiques utilisées. Compte tenu de l'extension du permafrost canadien et du développement du Nord canadien, les cartes du permafrost
Some observations regarding mountain permafrost in the Japanese Alps
Geophysics ; Japan ; Mountain ; Periglacial features ; Permafrost ; Rock glacier
In the early 1970s permafrost was discovered from 2 Japanese volcanoes, Mt. Fuji and Mt. Daisetu, by means of shallow drilling and geophysical sounding. The last 2 decades have encountered a rapid progress in mountain permafrost researches. The most
important conclusion is that ice-rich permafrost can move downslope, producing a specific landform called a rock glacier.
In areas with under 50 cm snow cover in winter, the permafrost zones can be defined by freezing indices and thawing indices. The relationship works for Norway, Spitsbergen, Canada and Mongolia, and since these include a very wide range of thermal
environments, it is possible to trace the thermal ranges of the various active periglacial landforms. Relationships between zonal permafrost landforms and permafrost zones are emphasized.
Recent contributions to the study of past permafrost
Recent adavances in permafrost and periglacial research. Special issue
Bibliography ; Europe ; Ice wedge ; Inherited features ; Micromorphology ; Palaeo-environment ; Periglacial features ; Permafrost ; Pleistocene ; Quaternary ; Stratigraphy ; Thermokarst ; United States of America
This paper reviews recent literature published between 2002 and 2007, concerning the previous existence of permafrost (past permafrost) that formed during the cold periods of the Pleistocene in the northern mid-latitudes. Some past permafrost
continues to be preserved today as relict permafrost in the higher northern latitudes. Given that global climate warming models predict widespread thaw of permafrost in the coming century, it is surprising that little attention has been given to the insights
that past and relict permafrost offer as to the nature and duration of permafrost thaw.
This paper reports the formation of new discontinuous permafrost and very late seasonal ground thawing in North Sweden. The results are discussed in a historical perspective and in relation to recent climatic variability.