scholarly journals Ground temperatures and recent coastal change at the north end of Richards Island, Mackenzie Delta, Northwest Territories

1993 ◽  
Author(s):  
L Dyke ◽  
S Wolfe

1975 ◽  
Vol 12 (8) ◽  
pp. 1421-1438 ◽  
Author(s):  
M. W. Smith

Variations in ground thermal regime were studied over a small area in the east-central part of the Mackenzie Delta, Northwest Territories, about 50 km northwest of Inuvik. Vegetation shows a successional sequence related to river migration and there is a complex interaction between vegetation, topography, and microclimate.Measurements from five sites show that significant differences in thermal regime exist beneath various types of vegetation. There is a general decrease in mean annual ground temperatures with increasing vegetation. The mean annual air temperature in this area is −9 °to −10 °C, but microclimatic factors lead to mean surface temperatures of between 0 °C and −4.2 °C.In summer, variations in net radiation account for the differences in ground thermal regime at the three sites on the slip-off slope. At the other two sites a surface layer of moss and peat leads to small values in ground heat flux and is instrumental in maintaining lower temperatures there. Removal of 10 cm of organic material at one site led to an increase of 3 °C in the mean daily 10 cm temperature.In winter, on the slip-off slope, variations in snow accumulation lead to ground temperature variations greater than those due to vegetation per se. Spatial variation of about 20 °C in ground surface temperature was measured in March 1970; during July and August 1970 the maximum spatial variation observed was only 10 °C. Differences of up to 6 °C in 1 m temperatures were measured over a distance of only 12 m. Snow cover is a permafrost-controlling factor in this area; where accumulations are greatest a talik has formed due to the insulating effect of deep snow.



2009 ◽  
Vol 20 (2) ◽  
pp. 127-139 ◽  
Author(s):  
J. C. N. Kanigan ◽  
C. R. Burn ◽  
S. V. Kokelj




Archaeologia ◽  
1779 ◽  
Vol 5 ◽  
pp. 98-100
Author(s):  
West

On sinking the cellars for a large house at the upper part of Church-street in this town, now building by Daniel Wilson, esq. on the site of which stood some very old houses (formerly called the Judge's lodgings), was discovered, at about six feet below the present surface of the street, a supposed Roman burying-place; as burnt wood, bones, and ashes, broken paterae, urns, Roman brick, gutter tiles, coins, horns of animals, &c. were found; also, two fragments of thick walls, at about five yards distant from each other, in a direction from front to back, and seeming to continue under Church-street, be-twixt which were several large stones, some of which were hewn. By this it may be conjectured, to have been a vault to deposit the ashes of the dead, and fallen-in, or pulled down, at some time, as there were found, within the walls, several pieces of urns, an earthen sepulchral lamp entire (the end of the spout where the wick came out was burnt black), broken paterae, burnt bones, ashes, a large human skull, Roman coins, &c. also, at the North-end a well, filled with hewn stones, but not meddled with.



1999 ◽  
Vol 29 ◽  
pp. 131-135 ◽  
Author(s):  
M. Guglielmin ◽  
F. Dramis

AbstractKnowledge of permafrost characteristics and distribution in Antarctica and their relationships with present and past climates is still poor. This paper reports investigations on permafrost in an area located between Nansen Ice Sheet to the south and Mount Melbourne (2732 m a.s.l.) to the north. Investigation methods included geomorphological surveys and geoelectrical soundings as well as crystallography, chemical and isotopic analyses of the ground ice. Geomorphological surveys helped to explain the relationships between periglacial landforms (e.g. rock glaciers and patterned ground) and the glacial history of the area. Geoelectrical soundings allowed us to define different ground-ice units in the ice-free areas. Each unit was characterised by a different type of permafrost (dry or ice-poor permafrost, marine or continental massive buried ice and sub-sea permafrost). To identify the nature of ground ice, trenches were dug and some shallow boreholes were drilled to a maximum depth of-3.6 m in massive buried ice. Samples of both ice-poor permafrost and massive ice were collected and analyzed. Chemical, isotopic δ18O and crystal analyses were also carried out. The relationships between climate and thermal regimes of the active layer and the upper part of permafrost were determined using a monitoring station for ground temperatures at Boulder Clay Glacier, near the Italian Antarctic station. During winter, there were several significant thermal-inversion events in the ground, which cannot be explained only by air-temperature changes, suggesting a possible influence of winter snowfall, even if these events are usually considered very rare.



1851 ◽  
Vol 2 ◽  
pp. 144-145
Author(s):  
J. A. Broun

The absolute westerly declination at Makerstoun, for the mean epoch, June 1844 = 25° 17′·12.The annual motion of the north end of the needle towards the east = 5′·67.The annual periodof magnetic declination consists of a double oscillation, having nearly the following epochs of maxima and minima.



Author(s):  
Tri Muji Susantoro ◽  
Ketut Wikantika ◽  
Lissa Fajri Yayusman ◽  
Alex Tan ◽  
M. Firman Ghozali

Severe abrasion occurred in the coastal area of Brebes Regency, Central Java between 1985 and 1995. Since 1997, mangroves have been planted around the location as a measure intended to prevent further abrasion. Between 1996 and 2018, monitoring has been carried out to assess coastal change in the area and the growth and development of the mangroves. This study aims to monitor mangrove growth and its impact on coastal area changes on the north coast of Brebes, Central Java Province using Landsat series data, which has previously proven suitable for wetland studies including mangrove growth and change. Monitoring of mangrove growth was analysed using the normalised difference vegetation index (NDVI) and the green normalised difference vegetation index (GNDVI) of the Landsat data, while the coastal change was analysed based on the overlaying of shoreline maps. Visual field observations of WorldView 2 images were conducted to validate the NDVI and GNDVI results. It was identified from these data that the mangroves had developed well during the monitoring period. The NDVI results showed that the total mangrove area increased between 1996 and 2018 about 9.82 km2, while the GNDVI showed an increase of 3.20 km2. Analysis of coastal changes showed that the accretion area about 9.17 km2 from 1996 to 2018, while the abrasion being dominant to the west of the Pemali River delta about 4.81 km2. It is expected that the results of this study could be used by government and local communities in taking further preventative actions and for sustainable development planning for coastal areas.



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