Frost heave on earth hummocks (pounus) in Finnish Lapland
Cold area ; Finland ; Freezing ; Frost action ; Ground survey ; Lapland ; Periglacial features ; Snow
Frost heave, frost and snow depths on 2 earth hummocks (pounus) were monitored from 1992 to 2002 in Finnish Lapland. Frost heave was measured with motometers, frost depth with Gandahl's frost tube containing methylene blue, and snow depth with frost
tubes above the ground surface. Frost heave values on the pounus did not differ much from those from the surrounding mire. During the early summer, slow thawing of frost keeps the surface of pounus higher than the surrounding mire surface
Laboratory experiments on frost shattering of rocks
Presents a quantitative expression of the frost shattering rate including temperature moisture and lithology. The water migration caused by unfrozen-adsorbed pore-water may play a large role in the frost shattering. The water migration toward
the frozen part may contribute to increase the frost shattering (measurements on matric potential and water content during freezing). Freezing expansion of porous rocks was measured.
Frost weathering and ice action in shore platform development with particular reference to Quebec, Canada in Periglacial processes and landforms.
The paper gives an account of frost weathering and ice action on rocky shores with particular reference to the eastern Hudson Bay and the St. Lawrence estuary. Frost shattering and frost wedging are two main processes involved in frost weathering
A krioplanacios meredek lejto kialakulasa és morfologiaja. (Evolution and morphology of the frost-riven scarp)
The most common varieties of forms on frost-riven scarps are erosional rills, dells/derasion valleys, frost cracks and frost seams. The grain composition of the blanket layer of scarps is controlled by slope exposure. The primary governing agent
in the evolution of the scarps is frost action disintegrating bedrock. (DLO).
Frost and soils : implications for paleosols, paleoclimates and stratigraphy
Frost is a pedogenetic agent. This paper describes the use of frost features in soil for paleoclimatic and stratigraphic interpretation. It is possible to differentiate periods of frost activity from those of temperate pedogenesis by macroscopic
and microcopic criteria. The interrelations between frost and other pedogenetic processes allow a better understanding of climatic evolution and deterioration throughout the Neogene and especially during the Quaternary and the Holocene. Most of the inherited
frost features in European soils are younger than 480 ka BP. The differentiation between frost and tectonic pertubations is very important for calculation of soil erosional budgets.
This paper is founded on experiences from three decades of geomorphological studies of active and relict frost-fissure patterns in different parts of the Nordic countries including Greenland. The climatic conditions necessary for the frost-fissure
Seasonal ground frost occurrence : developing a statistically-based predictive model
Results suggest that although frost penetration can often be approximated on the basis of freezing degree days, the last frost observed and a qualitative assessment of soil moisture, the overall accuracy of the predictive model is undermined
Observations on the 1972 frosts and subsequent relief programme among the Enga of the Western Highlands in Frost and drought in the Highlands of Papua New Guinea.
Widespread crop destruction by frost as low as 1 650 m initiated an ill-conceived relief program by outsiders that contrasted with Enga adaptive strategies. - (DWG)
Aapasuon routaa säätelevät tekijät - esimerkkitapaus Kuusamosta (Factors controlling ground frost on an aapa mire in Kuusamo, Finland)
The chief factor controlling the frost horizon in the ground proved to be snow depth which was regulated by wind action, particularly in late winter. The vegetation had a considerable influence locally. The contribution of the third major factor
, the groundwater was seen principally in the fact that the mire accumulated less ground frost than other sites on average and that the frost began to melt almost a month earlier than in ordinary mineral soils.
Direct observation of frost wedging in alpine bedrock
This paper presents atomated monitoring of rock joint widening and temperatures, in autumn and spring, on 3 rock outcrops around Mount Ainodake, in the Akaishi Range, southern Japanese Alps, where a series of field observations on frost weathering
have been undertaken in 1990, 1994 and 1999. The data analysis focuses on the timing and magnitude of joint widening (frost wedging) in relation to subzero rock temperatures and frost penetration depth. The temperature range at which wedging occurs
The decreasing spring frost risks during the flowering period for woody plants in temperate area of eastern China over past 50 years
Bioclimatology ; China ; Climatic change ; Climatic hazard ; Climatic trend ; Frost ; North-Eastern China ; Northern China ; Phenology ; Spring (season) ; Temperate zone
of frost occurrence were analyzed. Through these analyses, frost risk during the flowering period at each site was estimated. Results suggested that first flowering dates (FFD) in the study area advanced significantly from 1963 to 2009 in North China. Over
the same period, the number of frost days in spring decreased and the last frost days advanced across the study area. Considering both flowering phenology and occurrence of frost, the frost risk index, which measures the percentage of species exposed
to frost during the flowering period in spring, exhibited a decreasing trend in Northeast China and in North China, implying that frost risk has reduced over the past half century.
Frost heaving and frost creep on an experimental slope : results for soil structures and sorted stripes in Periglacial processes and landforms.
the slope and varied in relation to changes in drainage and temperature gradients. The maximum frost creep occurred in the loamy material at the lower end of the slope where the intensity of the water supply and heaving were greater. Frost creep was shown
Frost heave and dry density changes during cyclic freeze-thaw of a silty clay
China ; Clay ; Cold area ; Experimentation ; Freeze-thaw cycle ; Frost ; Geotechnics ; Qinghai ; Railway ; Tibet
Open-system frost heave tests were performed on a silty clay using a lower boundary condition of +2°C and unidirectional freezing at -10°c from the surface, or freezing and thawing with an upper boundary temperature that cycled from -10°C to +10°C
or from -10°C to 0°C. The amont of frost heave, the distribution of moisture at the end of the experiment and the final dry density profiles all differed for the 3 cases. The experiments demonstrate that freeze-thaw history is important in assessing
This paper reviews frost-weathering studies in the last five years and proposes key questions to be answered. Field monitoring has highlighted the roles of diurnal and annual frost cycles in controlling the timing and magnitude of frost weathering
Scenarios of future climate change : effects on frost occurence and severity in the uplands of northern England
This paper has applied the results of different temperature change scenarios to analysis of changing frost parameters in northern England. The thermal climate of the region has been represented by comparing annual frost frequency and annual frost
accumulation (below 0°C) with the baseline situation. The baseline climate is based on backward stepwise regression using up to ten terrains variables. Changes in both frost parameters are considerable, especially in the 2 general circulation model (GCM
Migration from Yumbisa 1972-1975 in Frost and drought in the Highlands of Papua New Guinea.
Crop loss from the 1972 frost forced migration from the high Enga country of Papua New Guinea. Dispersion of gardens over a range of sites was a key factor in their adjustment. (DWG)