scholarly journals Using Ground Penetrating Radar for Permafrost Monitoring from 2015–2017 at CALM Sites in the Pechora River Delta

2021 ◽  
Vol 13 (16) ◽  
pp. 3271
Author(s):  
Maria Sudakova ◽  
Marat Sadurtdinov ◽  
Andrei Skvortsov ◽  
Andrei Tsarev ◽  
Galina Malkova ◽  
...  
Keyword(s):  
Water Content ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Thermal State ◽  
River Delta ◽  
Permafrost Degradation ◽  
Sandy Ground ◽  
Permafrost Table ◽  
Pechora River ◽  
Ground Penetrating

This paper describes the results of ground penetrating radar (GPR) research combined with geocryological data collected from the Circumpolar Active Layer Monitoring (CALM) testing sites in Kashin and Kumzha in August 2015, 2016, and 2017. The study area was located on the Pechora River delta. Both sites were composed of sandy ground and the permafrost depth at the different sites ranged from 20 cm to 8–9 m. The combination of optimum offset and multifold GPR methods showed promising results in these investigations of sandy permafrost geological profiles. According to direct and indirect observations after the abnormally warm conditions in 2016, the thickness and water content of the active layer in 2017 almost returned to the values in 2015 in the Kashin area. In contrast, the lowering of the permafrost table continued at Kumzha, and lenses of thin frozen rocks that were observed in the thawed layer in August of 2015 and 2017 were absent in 2016. According to recent geocryological and geophysical observations, increasing permafrost degradation might be occurring in the Pechora River delta due to the instability of the thermal state of the permafrost.

scholarly journals Monitoring of active layer dynamics at a permafrost site on Svalbard using multi-channel ground-penetrating radar

2010 ◽  
Vol 4 (1) ◽  
pp. 287-319 ◽  
Author(s):  
S. Westermann ◽  
U. Wollschläger ◽  
J. Boike
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Heat Content ◽  
Invasive Technique ◽  
Ground Heat Flux ◽  
Thaw Depth ◽  
Ground Penetrating

Abstract. Multi-channel ground-penetrating radar is used to investigate the late-summer evolution of the thaw depth and the average soil water content of the thawed active layer at a high-arctic continuous permafrost site on Svalbard, Norway. Between mid of August and mid of September 2008, five surveys have been conducted over transect lengths of 130 and 175 m each. The maximum thaw depths range from 1.6 m to 2.0 m, so that they are among the deepest thaw depths recorded for Svalbard so far. The thaw depths increase by approximately 0.2 m between mid of August and beginning of September and subsequently remain constant until mid of September. The thaw rates are approximately constant over the entire length of the transects within the measurement accuracy of about 5 to 10 cm. The average volumetric soil water content of the thawed soil varies between 0.18 and 0.27 along the investigated transects. While the measurements do not show significant changes in soil water content over the first four weeks of the study, strong precipitation causes an increase in average soil water content of up to 0.04 during the last week. These values are in good agreement with evapotranspiration and precipitation rates measured in the vicinity of the the study site. While we cannot provide conclusive reasons for the detected spatial variability of the thaw depth at the study site, our measurements show that thaw depth and average soil water content are not directly correlated. The study demonstrates the potential of multi-channel ground-penetrating radar for mapping thaw depth in permafrost areas. The novel non-invasive technique is particularly useful when the thaw depth exceeds 1.5 m, so that it is hardly accessible by manual probing. In addition, multi-channel ground-penetrating radar holds potential for mapping the latent heat content of the active layer and for estimating weekly to monthly averages of the ground heat flux during the thaw period.

scholarly journals Imaging of the Internal Structure of Permafrost in the Tibetan Plateau Using Ground Penetrating Radar

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 56 ◽  
Author(s):  
Yao Wang ◽  
Zhihong Fu ◽  
Xinglin Lu ◽  
Shanqiang Qin ◽  
Haowen Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Complex Structure ◽  
Real Data ◽  
Imaging Method ◽  
The Tibetan Plateau ◽  
Permafrost Degradation ◽  
Time Migration ◽  
Ground Penetrating

The distribution of the permafrost in the Tibetan Plateau has dramatically changed due to climate change, expressed as increasing permafrost degradation, thawing depth deepening and disappearance of island permafrost. These changes have serious impacts on the local ecological environment and the stability of engineering infrastructures. Ground penetrating radar (GPR) is used to detect permafrost active layer depth, the upper limit of permafrost and the thawing of permafrost with the season’s changes. Due to the influence of complex structure in the permafrost layer, it is difficult to effectively characterize the accurate structure within the permafrost on the radar profile. In order to get the high resolution GPR profile in the Tibetan Plateau, the reverse time migration (RTM) imaging method was applied to GPR real data. In this paper, RTM algorithm is proven to be correct through the groove’s model of forward modeling data. In the Beiluhe region, the imaging result of GPR RTM profiles show that the RTM of GPR makes use of diffracted energy to properly position the reflections caused by the gravels, pebbles, cobbles and small discontinuities. It can accurately determine the depth of the active layer bottom interface in the migration section. In order to prove the accuracy of interpretation results of real data RTM section, we set up the three dielectric constant models based on the real data RTM profiles and geological information, and obtained the model data RTM profiles, which can prove the accuracy of interpretation results of three-line RTM profiles. The results of three-line RTM bears great significance for the study of complex structure and freezing and thawing process of permafrost at the Beiluhe region on the Tibetan Plateau.

scholarly journals Monitoring of active layer dynamics at a permafrost site on Svalbard using multi-channel ground-penetrating radar

2010 ◽  
Vol 4 (4) ◽  
pp. 475-487 ◽  
Author(s):  
S. Westermann ◽  
U. Wollschläger ◽  
J. Boike
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Invasive Technique ◽  
Ground Heat Flux ◽  
Gravelly Soil ◽  
Thaw Depth ◽  
Ground Penetrating

Abstract. Multi-channel ground-penetrating radar is used to investigate the late-summer evolution of the thaw depth and the average soil water content of the thawed active layer at a high-arctic continuous permafrost site on Svalbard, Norway. Between mid of August and mid of September 2008, five surveys have been conducted in gravelly soil over transect lengths of 130 and 175 m each. The maximum thaw depths range from 1.6 m to 2.0 m, so that they are among the deepest thaw depths recorded in sediments on Svalbard so far. The thaw depths increase by approximately 0.2 m between mid of August and beginning of September and subsequently remain constant until mid of September. The thaw rates are approximately constant over the entire length of the transects within the measurement accuracy of about 5 to 10 cm. The average volumetric soil water content of the thawed soil varies between 0.18 and 0.27 along the investigated transects. While the measurements do not show significant changes in soil water content over the first four weeks of the study, strong precipitation causes an increase in average soil water content of up to 0.04 during the last week. These values are in good agreement with evapotranspiration and precipitation rates measured in the vicinity of the the study site. While we cannot provide conclusive reasons for the detected spatial variability of the thaw depth at the study site, our measurements show that thaw depth and average soil water content are not directly correlated. The study demonstrates the potential of multi-channel ground-penetrating radar for mapping thaw depth in permafrost areas. The novel non-invasive technique is particularly useful when the thaw depth exceeds 1.5 m, so that it is hardly accessible by manual probing. In addition, multi-channel ground-penetrating radar holds potential for mapping the latent heat content of the active layer and for estimating weekly to monthly averages of the ground heat flux during the thaw period.

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