Resistivity structures in alas areas in Central Yakutia, Siberia, and the interpretation of permafrost history

Abstract

Deep resistivity structures of permafrost in Siberia were investigated using a transient electromagnetic (TEM) method. The data were compared with temperature profiles. The high and low resistivity layers corresponded to permafrost and a talik, respectively, and the boundary between high and low resistivity was in good agreement with the temperature profile. In TEM surveys conducted from an alas to the taiga forest, the permafrost base was detected at a depth of more than 400 m. This corresponds to the known permafrost depth in this area. A talik was also found to exist at a depth of 100-200 m. Numerical studies indicate that the talik could have been produced by a thermokarst lake. The estimated period after initiation of alas formation agrees with radiocarbon dating results. In combination with the numerical analysis, the geo-electrical information provides a basic model for reconstructing the history of permafrost.

Internal Structure of Open System Pingos, Adventdalen, Svalbard: The Use of Resistivity Tomography to Assess Ground-Ice Conditions

“…However, this is not the case in many areas of lowland permafrost, where permafrost is developed within thick sequences of unconsolidated, fine-grained superficial sediments, or in areas of sedimentary or volcanic bedrock. Permafrost resistivities in these settings are normally much lower (1-10 kV m) (e.g., Hoekstra et al, 1975;Allard et al, 1988;Sellmann et al, 1988;Gahe et al, 1988;Delaney et al, 1988;Harada et al, 2000Harada et al, , 2006Farbrot et al, 2005;Etzelmü ller et al, 2006), although values remain much greater than the unfrozen equivalents. This paper describes electrical resistivity tomography surveys of open system pingos in Adventdalen, Svalbard.…”

Permafrost degradation as a control on hydrogeological regime shifts in a warming climate

“…Consequently, inter‐glacial periods when ground surface temperatures are high enough to thaw permafrost, do often not last long enough to fully remove permafrost before average annual temperatures drop below freezing in the next glacial cycle, and permafrost starts to develop again from the surface downward. Numerical models adopting the latter scenario have been used to explain the occurrence of intrapermafrost talik zones as observed in Siberia [ Harada et al , 2006] and the Mackenzie Delta [ Allen et al , 1988; Taylor et al , 1996]. In a more generic evaluation, Majorowicz et al [2008]show that steady state thermal conditions are unlikely to exist at the present‐day as a result of regional and local ground surface temperature fluctuations over the past millennia.…”

“…In a more generic evaluation, Majorowicz et al [2008]show that steady state thermal conditions are unlikely to exist at the present‐day as a result of regional and local ground surface temperature fluctuations over the past millennia. Transient temperature conditions have been observed underneath thaw lakes [ Mackay , 1997; Mackay and Burn , 2002], which model simulations have shown [ Zhou and Huang , 2004; Ling and Zhang , 2004] to likely result from repeated surface cooling and warming due to the cyclicity of drainage and filling of thaw lakes [e.g., Harada et al , 2006]. Recently, Rowland et al [2011] presented numerical modeling results suggesting that advective heat transport by upwelling groundwater into talik lakes can be an important process locally reducing permafrost thickness and preventing the closure of the talik by permafrost development.…”

Deep groundwater and potential subsurface habitats beneath an Antarctic dry valley

“…Recently, AEM has been used in the Arctic to map the extent of permafrost in Alaska 32 . Surveys based on similar, but ground-based, technologies have also been used in the Arctic to delineate taliks within permafrost 33 34 35 and to map permafrost and buried ice features on Livingston Island, Antarctica 36 .…”