scholarly journals Permafrost presence and distribution in the Chic-Chocs Mountains, Gaspésie, Québec

2011 ◽  
Vol 33 (3-4) ◽  
pp. 299-316 ◽  
Author(s):  
James T. Gray ◽  
Roger J. E. Brown
Keyword(s):  
Ground Surface ◽  
Drill Hole ◽  
Temperature Data ◽  
Ground Temperature ◽  
Flow Data ◽  
Conductivity Measurements ◽  
Profile Data ◽  
Ground Surface Temperature ◽  
Permafrost Table ◽  
Mean Annual Air Temperature

Ground temperature studies, begun in 1977, revealed the presence of permafrost at the summit of Mont Jacques-Cartier (1270 m), in Gaspésie. Temperature profile data to a depth of 30 m in a drill hole indicates an active layer slightly thicker than 5.75 m, overlying a permafrost body extending beyond the base of the hole. Downward extrapolation of the profile, based on heat flow data and thermal conductivity measurements show that this permafrost body is from 45-60 m thick. That the permafrost is contemporary is indicated by the proximity of the permafrost table to the surface, by the low mean annual air temperature for the site (-3°C to -5°C), and by the lack of a thick insulative blanket of snow in the winter. A mean annual ground surface temperature of -1°C to -1.5°C is estimated for the site. The Mont Jacques-Cartier data enabled a regional lower limit of 1,000 — 1,100 m to be established for extensive permafrost in the Chic-Chocs Mountains in treeless exposed situations. A limited amount of ground temperature data from Mont Logan and Mont Albert tends to confirm the validity of this regional limit, which was then used, in association with our knowledge of the vegetation cover, to map the distribution of extensive permafrost bodies for the entire eastern Chic-Chocs Mountains. Although not observed in this study, permafrost may exist below this regional limit, in either coarse debris accumulations, or in organic terrains at high altitudes subject to sufficiently thick accumulations of peat

scholarly journals Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling

2013 ◽  
Vol 9 (1) ◽  
pp. 119-133 ◽  
Author(s):  
D. Mottaghy ◽  
G. Schwamborn ◽  
V. Rath
Keyword(s):  
Surface Temperature ◽  
Thermal Regime ◽  
Climate Changes ◽  
Ground Surface ◽  
Temperature Data ◽  
Ice Age ◽  
Drilling Process ◽  
Past Climate ◽  
Ground Surface Temperature ◽  
Recent Climate

Abstract. This study focuses on the temperature field observed in boreholes drilled as part of interdisciplinary scientific campaign targeting the El'gygytgyn Crater Lake in NE Russia. Temperature data are available from two sites: the lake borehole 5011-1 located near the center of the lake reaching 400 m depth, and the land borehole 5011-3 at the rim of the lake, with a depth of 140 m. Constraints on permafrost depth and past climate changes are derived from numerical simulation of the thermal regime associated with the lake-related talik structure. The thermal properties of the subsurface needed for these simulations are based on laboratory measurements of representative cores from the quaternary sediments and the underlying impact-affected rock, complemented by further information from geophysical logs and data from published literature. The temperature observations in the lake borehole 5011-1 are dominated by thermal perturbations related to the drilling process, and thus only give reliable values for the lowermost value in the borehole. Undisturbed temperature data recorded over more than two years are available in the 140 m deep land-based borehole 5011-3. The analysis of these observations allows determination of not only the recent mean annual ground surface temperature, but also the ground surface temperature history, though with large uncertainties. Although the depth of this borehole is by far too insufficient for a complete reconstruction of past temperatures back to the Last Glacial Maximum, it still affects the thermal regime, and thus permafrost depth. This effect is constrained by numerical modeling: assuming that the lake borehole observations are hardly influenced by the past changes in surface air temperature, an estimate of steady-state conditions is possible, leading to a meaningful value of 14 ± 5 K for the post-glacial warming. The strong curvature of the temperature data in shallower depths around 60 m can be explained by a comparatively large amplitude of the Little Ice Age (up to 4 K), with low temperatures prevailing far into the 20th century. Other mechanisms, like varying porosity, may also have an influence on the temperature profile, however, our modeling studies imply a major contribution from recent climate changes.

scholarly journals NORPERM, the Norwegian Permafrost Database – a TSP NORWAY IPY legacy

2010 ◽  
Vol 3 (1) ◽  
pp. 27-54 ◽  
Author(s):  
H. Juliussen ◽  
H. H. Christiansen ◽  
G. S. Strand ◽  
S. Iversen ◽  
K. Midttømme ◽  
...  
Keyword(s):  
Thermal State ◽  
Ground Surface ◽  
Temperature Data ◽  
Ground Temperature ◽  
Future Research ◽  
Research Project ◽  
International Polar Year ◽  
Standard Format ◽  
Data Infrastructure ◽  
Data Loggers

Abstract. NORPERM – The Norwegian Permafrost Database was developed at the Geological Survey of Norway during the International Polar Year (IPY) 2007–2009 as the main data legacy of the IPY research project Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY). This paper describes the structural and technical design of NORPERM. NORPERM follows the IPY data policy of open, free, full and timely release of IPY data, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P) standard. The ground temperature data infrastructure in Norway and Svalbard is also presented, focussing on the TSP NORWAY permafrost observatory installations in the North Scandinavian Permafrost Observatory and Nordenskiöld Land Permafrost Observatory, as the data providers for NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed. The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. NORPERM stores temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. It contains all the temperature data from the TSP NORWAY research project, totalling 32 boreholes and 98 sites with miniature temperature data-loggers for continuous monitoring of micrometeorological conditions, and 6 temperature depth profiles obtained by manual borehole logging. The amount of data in the database will gradually increase as data from older, previous projects are added. NORPERM also provides links to near real-time permafrost temperatures obtained by GSM data transfer.

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