Geophysical Observations of Taliks Below Drained Lake Basins on the Arctic Coastal Plain of Alaska

Abstract

Lakes and drained lake basins (DLBs) combined are estimated to cover up to ∼80% of the western Arctic Coastal Plain of Alaska (∼30,000 km 2) (Grosse et al., 2013; Hinkel et al., 2005; Jones & Arp, 2015). There are a variety of lake types in the Arctic, but the most common are thermokarst lakes in lowland regions with ice-rich permafrost (Grosse et al., 2013; Kling, 2009) that form due to permafrost thaw and surface subsidence. Deeper lakes developed in permafrost terrain are often underlain by layers or bodies of perennially unfrozen ground below the lake bed known as a talik (van Everdingen, 1998). Arctic lakes can persist for thousands of years, but, due to ongoing margin expansion and other landscape changes, they eventually drain laterally to create a mosaic of extant lakes and DLBs (Hinkel et al. 2007; Mackay, 1992). Arctic lake drainage can occur through a variety of processes, and where and when lake drainage occurs influences landscape succession and permafrost aggradation (refreezing of the talik). Remote-sensing analysis of historical imagery of the western Arctic Coastal Plain of Alaska identified that 1-2 lakes larger than 10 ha have partially (>25% area reduction) or completely drained per year between

Rapid Saline Permafrost Thaw Below a Shallow Thermokarst Lake in Arctic Alaska

“…Assuming that the water resistivity and mineral phase remain constant, then reduction of ice in pore spaces would be the only property to explain the difference in resistivity over time. Differences in in situ measured pore water electrical properties (Figure 2) and bulk electrical conductivity measured by TEM (Figure 3) in this study are expected due to differences in sampling volumes of the two measurements and the fact that the sonde measures fluid electrical conductivity while the TEM measures bulk electrical properties (Rangel et al, 2021). (2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022) for a floating ice lake with relatively freshwater (West Twin Lake), a lake that transitioned from bedfast to floating with brackish water below the ice (East Twin Lake), and a floating ice lake with brackish water below the ice over the entire study period (Lake 113).…”

“…Assuming that the water resistivity and mineral phase remain constant, then reduction of ice in pore spaces would be the only property to explain the difference in resistivity over time. Differences in in situ measured pore water electrical properties (Figure 2) and bulk electrical conductivity measured by TEM (Figure 3) in this study are expected due to differences in sampling volumes of the two measurements and the fact that the sonde measures fluid electrical conductivity while the TEM measures bulk electrical properties (Rangel et al., 2021).…”

“…Saline permafrost thaw is thought to be a factor in increasing erosion rates along Arctic coastlines (Bristol et al., 2021; Jones et al., 2018; Lorenson et al., 2018). In addition, near‐surface geophysical studies on the ACP focused on quantifying permafrost degradation below lakes (Creighton et al., 2018; Parsekian et al., 2019) as well as permafrost aggradation in drained lake basins (Rangel et al., 2021) has revealed the likely influence of salinity on the presence of unfrozen liquid pore water in the permafrost.…”

Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard

“…Elsewhere within the ERT profiles (Figures 5 and 6), and particularly at depths greater than 8 m, persistent low resistivity values (10 1 –10 3 Ωm) can be interpreted as permafrost. Whilst the resistivity of permafrost is commonly between 1 and 1 MΩm (Kneisel & Hauck, 2008), previous studies conducted further up‐valley (Harada & Yoshikawa, 1996; Ross et al., 2007) and in other coastal environments (Rangel et al., 2021; Yoshikawa et al., 2006) have demonstrated that permafrost resistivities can be substantially reduced in cases where sediments contain unfrozen porewater due to high dissolved salt content. Indeed, porewater salinities of 30–40 ppt have been recorded in Adventdalen (Gilbert et al., 2019).…”

Geophysical Approach to Delineate Groundwater Potentials in the Northwestern Part of Wadi Dara, Eastern Desert, Egypt

“…The 2D-ERI approach, on the other hand, is regarded as the first geophysical technique to be intended for locations with limited subsurface data (Dos Santos Gomes et al, 2018;Zarif et al, 2021a andJunaid et al, 2022). Electrical and electromagnetic tools are performed to evaluate groundwater resources because they are both sensitive to physical and chemical variations in the subsurface associated with changing groundwater quality (Louis et al, 2002;Bowling et al, 2007;Rangel et al, 2021 andZarif et al, 2021b).…”