Late Pleistocene–Holocene ground surface heat flux changes reconstructed from borehole temperature data (the Urals, Russia)

Demezhko, D. Yu.; Gornostaeva, A. A.

doi:10.5194/cp-11-647-2015

Cited by 21 publications

(16 citation statements)

References 32 publications

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“…Comparison to other temperature data Figure 4 shows the trends of the resulting temperature histories at Mamontov Klyk and Sardakh Island in comparison to other local records from the region as well as to larger scale temperature trends. To be able to compare these records to the geothermal reconstruction, their annually resolved time series were averaged using the non-uniform running windows of the minimum event resolution referenced to the year 2011/2012 CE [18].…”

Section: Discussionmentioning

confidence: 99%

“…Consequently, we choose methods that do not specify high-frequency changes in the past. In addition, a procedure of averaging with non-uniform running windows should be used whenever comparing temperature time series of constant temporal resolution (such as annual observations) to geothermal reconstructions [18]. To estimate the past surface temperature history T j from the borehole temperature observations, two inverse methods (LSQR and Particle Swarm) were used with the forward soil model to optimize a surface temperature history for each of the borehole sites (Sects.…”

Section: Optimizationmentioning

confidence: 99%

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Borehole temperature reconstructions reveal differences in past surface temperature trends for the permafrost in the Laptev Sea region, Russian Arctic

Kneier

Overduin

Langer

et al. 2018

Arktos

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In central Siberia, past temperature changes have been driving permafrost warming in a region with large organic carbon reserves stored in the perennially frozen ground. However, local arctic temperature histories in the ice-rich permafrost areas of the remote Russian Arctic are sparsely known or based on proxy data with potential seasonal biases and underrepresented in circum-Arctic reconstructions. This study employed two inversion schemes (particle swarm optimization and a least-square method) to reconstruct temperature histories for the past 200-300 years in the Laptev Sea region from two permafrost borehole temperature records. These data were evaluated against larger scale reconstructions from the region. Distinct differences between the western Laptev Sea and the Lena Delta sites were recognized, such as a transition to warmer temperatures a century later in the western Laptev Sea as well as a peak in warming 3 decades later. The local permafrost surface temperature history at Sardakh Island in the Lena Delta was reminiscent of the circum-Arctic regional average trends. However, Mamontov Klyk in the western Laptev Sea was consistent to Arctic trends only in the most recent decade and was more similar to northern hemispheric mean trends. Both sites are consistent with a rapid recent warming that is of synoptic scale. Different environmental influences such as synoptic atmospheric circulation and sea ice may be responsible for differences between the sites. The shallow permafrost boreholes provide missing well-resolved short-scale temperature information in the coastal permafrost tundra of the Arctic. As local differences from circum-Arctic reconstructions, such as later warming and higher warming magnitude, were shown to exist in this region, our results provide a basis for local surface temperature record parameterization of climate models, and in particular of permafrost models.

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Section: Discussionmentioning

confidence: 99%

Section: Optimizationmentioning

confidence: 99%

Borehole temperature reconstructions reveal differences in past surface temperature trends for the permafrost in the Laptev Sea region, Russian Arctic

Kneier

Overduin

Langer

et al. 2018

Arktos

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“…(Demezhko and Shchapov, 2001) studied a ∼ 5 km deep borehole in the Urals, Russia, and found a postglacial warming of 12-13 K, with basal temperatures below the melting point of ice during the LGM. This was confirmed by recent work indicating that temperatures in the Urals were ∼ −8 • C at the LGM (Demezhko and Gornostaeva, 2015). In this study, we shall examine all the deep-borehole temperature profiles measured in central and eastern Canada in order to determine the temperature at the base of the Laurentide Ice Sheet, which covered the area during the LGC.…”

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confidence: 66%

“…They concluded that temperatures at the base of the ice sheet in Northern Alberta were about −3 • C during the LGM. On the other hand, studies of deep boreholes in Europe lead to different conclusions for the Fennoscandian Ice Sheet which covered parts of Eurasia during the LGC (see, e.g., Demezhko and Shchapov, 2001;Kukkonen and Jõeleht, 2003;Šafanda et al, 2004;Majorowicz et al, 2008;Demezhko et al, 2013;Demezhko and Gornostaeva, 2015) . (Kukkonen and Jõeleht, 2003) analyzed heat flow variations with depth in several boreholes from the Baltic Shield and the Russian Platform and found a 8 ± 4.5 K temperature increase following the LGM.…”

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confidence: 99%

Laurentide Ice Sheet basal temperatures during the last glacial cycle as inferred from borehole data

2016

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Abstract. Thirteen temperature-depth profiles ( ≥ 1500 m) measured in boreholes in eastern and central Canada were inverted to determine the ground surface temperature histories during and after the last glacial cycle. The sites are located in the southern part of the region that was covered by the Laurentide Ice Sheet. The inversions yield ground surface temperatures ranging from −1.4 to 3.0 • C throughout the last glacial cycle. These temperatures, near the pressure melting point of ice, allowed basal flow and fast flowing ice streams at the base of the Laurentide Ice Sheet. Despite such conditions, which have been inferred from geomorphological data, the ice sheet persisted throughout the last glacial cycle. Our results suggest some regional trends in basal temperatures with possible control by internal heat flow.

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“…SHF is positive in downward direction (from the surface to depth).Being an energy expression of climate variations this heat flux contrary to temperature might be directly compared with another energy characteristics (for example with solar insolation) to identify the origin of climate changes. The algorithm of GST -SHF transformation have been developed for SHF evaluation(Demezhko, Gornostaeva, 2015a). SHF histories obtained from GST histories mentioned above are shown inFig.…”

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confidence: 99%

Late Weichselian thermal state at the base of the Scandinavian Ice Sheet

Demezhko

Gornostaeva

Antipin

2019

Preprint

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Abstract. Geothermal estimates of the ground surface temperatures for the last glacial cycle in Northern Europe has been analyzed. During the Middle and Late Weichselian (55–12 kyr BP) a substantial part of this area was covered by the Scandinavian Ice Sheet. The analysis of geothermal data has allowed reconstructing limits of the ice sheet extension and its basal thermal state in the Late Weichselian. Ground surface temperatures outside the ice sheet were extremely low (from −8 to −18 °C). Within the ice sheet, there were both thawed and frozen zones. The revealed temperature pattern is generally consistent with the modern one for the ground surface temperatures in Greenland that makes it possible to consider these ice sheets as analogues. The anomalous climatically induced surface heat flux and orbital insolation of the Earth varied consistently outside the glaciation and independently within the limits of the ice sheet.

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Late Pleistocene–Holocene ground surface heat flux changes reconstructed from borehole temperature data (the Urals, Russia)

Cited by 21 publications

References 32 publications

Borehole temperature reconstructions reveal differences in past surface temperature trends for the permafrost in the Laptev Sea region, Russian Arctic

Borehole temperature reconstructions reveal differences in past surface temperature trends for the permafrost in the Laptev Sea region, Russian Arctic

Laurentide Ice Sheet basal temperatures during the last glacial cycle as inferred from borehole data

Late Weichselian thermal state at the base of the Scandinavian Ice Sheet

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