Summer thaw depths in cold regions and fossil cryoturbation
An analysis of data from the literature, on summer thaw depths and cryoturbation in present-day cold areas, shows that the thickness of fossil cryoturbated deposits cannot be correlated to the July temperature of that time. It is suggested
A laboratory simulation of rock breakdown due to freeze-thaw in a maritime antarctic environment
Results of freeze-thaw simulations on three large blocks of quartz-micaschist are presented. Identification of three types of water to ice phase change from temperature and ultrasonic measurements. It is suggested that the type of phase change
results from a particular combination of rock moisture content, solute concentration, freeze amplitude, and rate of fall of temperature. The temperature at which ice thawed inside the rock (-0.7 to 1.9oC) was also found, and this indicates the possibility
of freeze-thaw effects without positive temperatures.
The freeze-thaw weathering regime at a section of the Niagara Escarpment on the Bruce Peninsula, southern Ontario, Canada
Fewer freeze-thaw cycles were recorded in the air than at 1 and 3.5 cm in the bedrock, between December 1983 and April 1984. The number of cycles that could be declared geomorphologically effective according to established temperature criteria
was normally less than half the total number of freeze - thaw cycles recorded in both air and bedrock. Under the current temperature regime at the field site, few effective cycles are capable of penetrating more than 5 cm into the free face.
Distribution of zonal permafrost landforms with freezing and thawing indices
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
Freeze-thaw and wetting-drying experiments with about 90 different Swedish rocks are described. On an average sandstones decompose 11 times faster than granites. The soft sedimentary rocks included in the experiment have produced between 1 100
and 31 000 times more material of grain sizes less than 1 mm than the mean for granites. The observed weathering rate from the freeze-thaw cycles is about 100 times slower than the rate calculated by measuring the height of quartz veins above
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.
In areas with under 50cm snow cover in winter, the permafrost zones are defined by the freezing indices and thawing indices. The warmer boundary of the zone of continuous permafrost traverses the mean annual air temperature (MAAT). The boundary
between discontinuous and sporadic permafrost lies just on the cold side of 0C MAAT. The sporadic permafrost zone includes the zone of ice caves and the regions with patches of ice beneath ponds and peatbogs, out to 5C MAAT at a thawing index of 4000
The main aim of this paper is to examine geomorphic activity in the central Karakoram, between 3 000 and 6 000 m, where precipitation seasonally released meltwaters and freeze-thaw cycles are relatively abundant. Glacier ablation zones compose
A comparison is made between winter snow cover, Continentality Index values, freezing and thawing indices, and the apparent edaphic-ecological wetness and dryness of the sites as judged by distribution of differing types of alpine vegetation, soils
In the province of Maine, during the Pleistocene cold episodes, many freeze-thaw cycles induced frost splitting of porous rocks such as jurassic limestones and palaeozoic rhyolite, and the frost wedging of non-porous paleozoic sandstones. Head
Experiments are described in which chalk cubes were soaked in solutions of either sodium chloride, sodium sulphate, or magnesium sulphate. After removal of excess liquid, the cubes were subjected to six freeze-thaw cycles with temperatures ranging