Climate trends in northern Ontario and Québec from borehole temperature profiles

Abstract

Abstract. The ground surface temperature histories of the past 500 years were reconstructed at 10 sites containing 18 boreholes in northeastern Canada. The boreholes, between 400 and 800 m deep, are located north of 51 • N and west and east of James Bay in northern Ontario and Québec. We find that both sides of James Bay have experienced similar ground surface temperature histories with a warming of 1.51 ± 0.76 K during the period of 1850 to 2000, similar to borehole reconstructions for the southern portion of the Superior Province and in agreement with available proxy data. A cooling period corresponding to the Little Ice Age was found at only one site. Despite permafrost maps locating the sites in a region of discontinuous permafrost, the ground surface temperature histories suggest that the potential for permafrost was minimal to absent over the past 500 years. This could be the result of air surface temperature interpolation used in permafrost models being unsuitable to account for the spatial variability of ground temperatures along with an offset between ground and air surface temperatures due to the snow cover.

Recent climate variations in Chile: constraints from borehole temperature profiles

“…Data availability. The borehole temperature-depth profiles measured in 2012 and 2015 were uploaded to figshare (https: //figshare.com/articles/ChileData_zip/5220964 - Pickler et al, 2017) and published with doi:10.6084/m9.figshare.5220964.v2. The temperature-depth profiles from 1992 were obtained from Andrea Förster and can be found in Springer (1997) and Springer and Förster (1998).…”

“…All the sites used in this study are located in the Atacama Desert, an arid region with little to no vegetation, and the holes had been drilled for mining exploration purposes. The temperature profiles were measured during three different campaigns in 1994, 2012, and 2015 (Springer, 1997;Springer and Förster, 1998;Gurza Fausto, 2014;Pickler et al, 2017). The data were obtained using different measurement techniques.…”

Thermophysical properties of surficial rocks: a tool to characterize geothermal resources of remote northern regions

“…The duration and surface temperature perturbations of each Pleistocene climate events in Northern Canada is still debatable and several models have been proposed (e.g., Beltrami et al 2003;Birch 1948 and references therein; Chouinard and Mareschal 2009;Jaume-Santero et al 2016;Majorowicz et al 2005;Mareschal et al 1999;Pickler et al 2016). Therefore, three different ground surface temperature histories (GSTH) were used based on Birch (1948) and Jessop (1990) model of the Pleistocene glaciations (Fig.…”

Recent climate variations in Chile: constraints from borehole temperature profiles

“…As of the 1980s, the technique became more widespread due to concerns about rising global temperatures (Lachenbruch and Marshall, 1986;Lachenbruch, 1988). Over the years, many global, regional, and local reconstructions of GST have been undertaken (Huang et al, 2000;Harris and Chapman, 2001;Pollack and Smerdon, 2004;Jaume-Santero et al, 2016;Pickler et al, 2016). However, the majority of these studies have 20 focused on the Northern Hemisphere with little attention to the Southern Hemisphere and South America due to the scarcity of adequate data.…”