scholarly journals Spatial variability of active layer thickness detected by ground‐penetrating radar in the Qilian Mountains, Western China

2017 ◽  
Vol 122 (3) ◽  
pp. 574-591 ◽  
Author(s):  
Bin Cao ◽  
Stephan Gruber ◽  
Tingjun Zhang ◽  
Lili Li ◽  
Xiaoqing Peng ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Qilian Mountains ◽  
Western China ◽  
Active Layer Thickness ◽  
The Qilian Mountains ◽  
Ground Penetrating

Ground-penetrating radar-derived measurements of active-layer thickness on the landscape scale with sparse calibration at Toolik and Happy Valley, Alaska

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. H1-H11 ◽  
Author(s):  
Albert Chen ◽  
Andrew D. Parsekian ◽  
Kevin Schaefer ◽  
Elchin Jafarov ◽  
Santosh Panda ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Landscape Scale ◽  
Active Layer Thickness ◽  
Ground Penetrating ◽  
Happy Valley

Ground-penetrating radar-derived measurements of active-layer thickness on the landscape scale with sparse calibration at Toolik and Happy Valley, Alaska

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. H9-H19 ◽  
Author(s):  
Albert Chen ◽  
Andrew D. Parsekian ◽  
Kevin Schaefer ◽  
Elchin Jafarov ◽  
Santosh Panda ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Empirical Relationship ◽  
Monitoring Network ◽  
Active Layer Thickness ◽  
Antenna Coupling ◽  
Thaw Depth ◽  
Ground Penetrating ◽  
Happy Valley

Active-layer thickness (ALT) is an important parameter for studying surface energy balance, ecosystems, and hydrologic processes in cold regions. We measured ALT along 10 routes with lengths ranging from 0.7 to 6.9 km located on the Alaska North Slope near Toolik Lake and the Happy Valley airstrip (between 68.475° and 69.150°N, and [Formula: see text] and [Formula: see text]). Using a ground-penetrating radar (GPR) system in a common-offset configuration, we measured the two-way traveltimes from the surface to the bottom of the active layer at the end of summer, when the thaw depth was greatest. We used 500 and 800 MHz antennas; the 500 MHz antenna provided suitable vertical resolution, while producing more unambiguous active-layer reflections in the presence of nonideal antenna coupling and active layer inhomogeneity. We derived ALT measurements and their uncertainties from GPR two-way traveltimes, with mechanical probing for velocity calibration. Using an empirical relationship between the wave velocity and soil volumetric water content (VWC), we found that the velocities were consistent with soil VWCs ranging from 0.46 to 0.63. In 31% of traces, the permafrost table horizon was identifiable, resulting in ALT measurements with uncertainties of generally less than 25%. The average ALT was 48.1 cm, with a standard deviation of 16.1 cm. We found distinct patterns of ALT spatial variability at different sites and different length scales. At some sites, the ALT at one point was effectively uncorrelated with ALT at other points separated by lag distances as small as tens of meters; for other sites, there was correlation at lag distances up to approximately 400 m. The ALT statistics were similar to nearby long-term in situ ALT measurements from the Circumpolar Active Layer Monitoring Network, through which yearly ALT measurements have been made since 1990.

scholarly journals Using ground-penetrating radar, topography and classification of vegetation to model the sediment and active layer thickness in a periglacial lake catchment, western Greenland

2016 ◽  
Vol 8 (2) ◽  
pp. 663-677 ◽  
Author(s):  
Johannes Petrone ◽  
Gustav Sohlenius ◽  
Emma Johansson ◽  
Tobias Lindborg ◽  
Jens-Ove Näslund ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Vegetation Classification ◽  
Active Layer Thickness ◽  
Sediment Thickness ◽  
Catchment Scale ◽  
Scale Models ◽  
Ground Penetrating

Abstract. The geometries of a catchment constitute the basis for distributed physically based numerical modeling of different geoscientific disciplines. In this paper results from ground-penetrating radar (GPR) measurements, in terms of a 3-D model of total sediment thickness and active layer thickness in a periglacial catchment in western Greenland, are presented. Using the topography, the thickness and distribution of sediments are calculated. Vegetation classification and GPR measurements are used to scale active layer thickness from local measurements to catchment-scale models. Annual maximum active layer thickness varies from 0.3 m in wetlands to 2.0 m in barren areas and areas of exposed bedrock. Maximum sediment thickness is estimated to be 12.3 m in the major valleys of the catchment. A method to correlate surface vegetation with active layer thickness is also presented. By using relatively simple methods, such as probing and vegetation classification, it is possible to upscale local point measurements to catchment-scale models, in areas where the upper subsurface is relatively homogeneous. The resulting spatial model of active layer thickness can be used in combination with the sediment model as a geometrical input to further studies of subsurface mass transport and hydrological flow paths in the periglacial catchment through numerical modeling. The data set is available for all users via the PANGAEA database, doi:10.1594/PANGAEA.845258.

Estimating 3D variation in active-layer thickness beneath arctic streams using ground-penetrating radar

2009 ◽  
Vol 373 (3-4) ◽  
pp. 479-486 ◽  
Author(s):  
Troy R. Brosten ◽  
John H. Bradford ◽  
James P. McNamara ◽  
Michael N. Gooseff ◽  
Jay P. Zarnetske ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Active Layer Thickness ◽  
Arctic Streams ◽  
Ground Penetrating

scholarly journals Using ground-penetrating radar, topography and classification of vegetation to model the sediment and active layer thickness in a periglacial lake catchment, Western Greenland

2016 ◽  
Author(s):  
Johannes Petrone ◽  
Gustav Sohlenius ◽  
Emma Johansson ◽  
Tobias Lindborg ◽  
Jens-Ove Näslund ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Vegetation Classification ◽  
Active Layer Thickness ◽  
Sediment Thickness ◽  
Catchment Scale ◽  
Local Point ◽  
Scale Models ◽  
Ground Penetrating

Abstract. The geometries of a catchment constitute the basis for distributed physically based numerical modeling of different geoscientific disciplines. In this paper results from ground-penetrating radar (GPR) measurements, in terms of a 3D model of total sediment thickness and active layer thickness in a periglacial catchment in western Greenland, are presented. Using the topography, thickness and distribution of sediments are calculated. Vegetation classification and GPR measurements are used to scale active layer thickness from local measurements to catchment scale models. Annual maximum active layer thickness varies from 0.3 m in wetlands to 2.0 m in barren areas and areas of exposed bedrock. Maximum sediment thickness is estimated to be 12.3 m in the major valleys of the catchment. A method to correlate surface vegetation with active layer thickness is also presented. By using relatively simple methods, such as probing and vegetation classification, it is possible to upscale local point measurements to catchment scale models, in areas where the upper subsurface is relatively homogenous. The resulting spatial model of active layer thickness can be used in combination with the sediment model as a geometrical input to further studies of subsurface mass-transport and hydrological flow paths in the periglacial catchment through numerical modelling. The data set is available for all users via the PANGAEA database, https://doi.pangaea.de/10.1594/PANGAEA.845258.

scholarly journals Active Layer Stratigraphy and Organic Layer Thickness at a Thermokarst Site in Arctic Alaska Identified Using Ground Penetrating Radar

2015 ◽  
Vol 47 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Alessio Gusmeroli ◽  
Lin Liu ◽  
Kevin Schaefer ◽  
Tingjun Zhang ◽  
Timothy Schaefer ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Ground Penetrating Radar ◽  
Organic Layer ◽  
Arctic Alaska ◽  
Ground Penetrating

Spatial variability of permafrost active-layer thickness under contemporary and projected climate in Northern Alaska

2012 ◽  
Vol 35 (2) ◽  
pp. 95-116 ◽  
Author(s):  
Dmitry A. Streletskiy ◽  
Nikolay I. Shiklomanov ◽  
Frederick E. Nelson
Keyword(s):  
Spatial Variability ◽  
Layer Thickness ◽  
Active Layer ◽  
Active Layer Thickness ◽  
Northern Alaska

scholarly journals Warming permafrost and active layer variability at Cime Bianche, Western Alps

2014 ◽  
Vol 8 (4) ◽  
pp. 4033-4074
Author(s):  
P. Pogliotti ◽  
M. Guglielmin ◽  
E. Cremonese ◽  
U. Morra di Cella ◽  
G. Filippa ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Snow Cover ◽  
Layer Thickness ◽  
Active Layer ◽  
Ground Surface ◽  
Small Scale ◽  
Active Layer Thickness ◽  
Spatial And Temporal Variability ◽  
Monitoring Site ◽  
Surface Temperatures

Abstract. The objective of this paper is to provide a first synthesis on the state and recent evolution of permafrost at the monitoring site of Cime Bianche (3100 m a.s.l.). The analysis is based on seven years of ground temperatures observations in two boreholes and seven surface points. The analysis aims to quantify the spatial and temporal variability of ground surface temperatures in relation to snow cover, the small scale spatial variability of the active layer thickness and the warming trends on deep permafrost temperatures. Results show that the heterogeneity of snow cover thickness, both in space and time, is the main factor controlling ground surface temperatures and leads to a mean range of spatial variability (2.5±0.15°C) which far exceeds the mean range of observed inter-annual variability (1.6±0.12°C). The active layer thickness measured in two boreholes 30 m apart, shows a mean difference of 2.03±0.15 m with the active layer of one borehole consistently lower. As revealed by temperature analysis and geophysical soundings, such a difference is mainly driven by the ice/water content in the sub-surface and not by the snow cover regimes. The analysis of deep temperature time series reveals that permafrost is warming. The detected linear trends are statistically significant starting from depth below 8 m, span the range 0.1–0.01°C year−1 and decrease exponentially with depth. Our findings are discussed in the context of the existing literature.

scholarly journals Warming permafrost and active layer variability at Cime Bianche, Western European Alps

2015 ◽  
Vol 9 (2) ◽  
pp. 647-661 ◽  
Author(s):  
P. Pogliotti ◽  
M. Guglielmin ◽  
E. Cremonese ◽  
U. Morra di Cella ◽  
G. Filippa ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Snow Cover ◽  
Layer Thickness ◽  
Active Layer ◽  
Ground Surface ◽  
Small Scale ◽  
Active Layer Thickness ◽  
Spatial And Temporal Variability ◽  
Monitoring Site ◽  
European Alps

Abstract. The objective of this paper is to provide a first synthesis on the state and recent evolution of permafrost at the monitoring site of Cime Bianche (3100 m a.s.l.) on the Italian side of the Western Alps. The analysis is based on 7 years of ground temperature observations in two boreholes and seven surface points. The analysis aims to quantify the spatial and temporal variability of ground surface temperature in relation to snow cover, the small-scale spatial variability of the active layer thickness and current temperature trends in deep permafrost. Results show that the heterogeneity of snow cover thickness, both in space and time, is the main factor controlling ground surface temperatures and leads to a mean range of spatial variability (2.5 ± 0.1 °C) which far exceeds the mean range of observed inter-annual variability (1.6 ± 0.1 °C). The active layer thickness measured in two boreholes at a distance of 30 m shows a mean difference of 2.0 ± 0.1 m with the active layer of one borehole consistently deeper. As revealed by temperature analysis and geophysical soundings, such a difference is mainly driven by the ice/water content in the sub-surface and not by the snow cover regimes. The analysis of deep temperature time series reveals that permafrost is warming. The detected trends are statistically significant starting from a depth below 8 m with warming rates between 0.1 and 0.01 °C yr−1.

Sign in / Sign up

Export Citation Format

Share Document