Transient Electromagnetic Surveys for the Determination of Talik Depth and Geometry Beneath Thermokarst Lakes

Creighton, A.; Parsekian, Andrew D.; Angelopoulos, Michael; Jones, Benjamin M.; Bondurant, Allen C.; Engram, Melanie; Lenz, Josefine; Overduin, Paul; Grosse, Guido; Babcock, Esther; Arp, Christopher D.

doi:10.1029/2018jb016121

Cited by 24 publications

(38 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a future study, a larger NMR loop size could improve the ability to discern the talik base, but it is important to keep in mind that the depth of investigation with large loops can be limited in very high latitudes by the high magnetic field inclination (Parsekian et al, ). It is possible that deeper imaging the talik base could also be accomplished using other deeper‐penetrating geophysical methods such as transient electromagnetics (Creighton et al, ) or airborne electromagnetics (Minsley et al, ), though we hypothesize that such surveys would have limited success at the Kuparuk site, where electrically resistive subsurface conditions observed during initial testing indicated that multifrequency EM surveys would likely yield little useful information. Direct current electrical resistivity methods (e.g., Minsley et al, ; Sjöberg et al, ; Yoshikawa & Hinzman, ) would be more suited to the resistive subsurface materials at the Kuparuk site and could potentially provide useful supporting information on talik thickness.…”

Section: Discussionmentioning

confidence: 99%

Seasonal Subsurface Thaw Dynamics of an Aufeis Feature Inferred From Geophysical Methods

Terry¹,

Grunewald

Briggs³

et al. 2020

JGR Earth Surface

View full text Add to dashboard Cite

Aufeis are sheets of ice unique to cold regions that originate from repeated flooding and freezing events during the winter. They have hydrological importance associated with summer flows and winter insulation, but little is known about the seasonal dynamics of the unfrozen sediment layer beneath them. This layer may support perennial groundwater flow in regions with otherwise continuous permafrost. For this study, ground penetrating radar (GPR) were collected in September 2016 (maximum thaw) and April 2017 (maximum frozen) at the Kuparuk aufeis field on the North Slope of Alaska. Supporting surface nuclear magnetic resonance data were collected during the maximum frozen campaign. These point‐in‐time geophysical data sets were augmented by continuous subsurface temperature data and periodic Structure‐from‐Motion digital elevation models collected seasonally. GPR and difference digital elevation model data showed up to 6 m of ice over the sediment surface. Below the ice, GPR and nuclear magnetic resonance identified regions of permafrost and regions of seasonally frozen sediment (i.e., the active layer) underlain by a substantial lateral talik that reached >13‐m thickness. The seasonally frozen cobble layer above the talik was typically 3‐ to 5‐m thick, with freezing apparently enabled by relatively high thermal diffusivity of the overlying ice and rock cobbles. The large talik suggests that year‐round groundwater flow and coupled heat transport occurs beneath much of the feature. Highly permeable alluvial material and discrete zones of apparent groundwater upwelling indicated by geophysical and ground temperature data allows direct connection between the aufeis and the talik below.

show abstract

Section: Discussionmentioning

confidence: 99%

Seasonal Subsurface Thaw Dynamics of an Aufeis Feature Inferred From Geophysical Methods

Terry¹,

Grunewald

Briggs³

et al. 2020

JGR Earth Surface

View full text Add to dashboard Cite

show abstract

“…The modeled talik thickness after 5,000 years was 107 m, which is comparable to other studies. On the Alaskan coastal plain, thermokarst taliks over 90 m deep have been interpreted from TEM data (Creighton et al., 2018), and a talik 95 m deep was also interpreted from shallow seismics in the Lena Delta in Siberia (Schwamborn et al., 2002). In the initial phase of thermokarst development, the lake was completely isolated from Tiksi Bay (Figure 9a).…”

Section: Discussionmentioning

confidence: 99%

Thermokarst Lake to Lagoon Transitions in Eastern Siberia: Do Submerged Taliks Refreeze?

et al. 2020

Self Cite

View full text Add to dashboard Cite

As the Arctic coast erodes, it drains thermokarst lakes, transforming them into lagoons, and, eventually, integrates them into subsea permafrost. Lagoons represent the first stage of a thermokarst lake transition to a marine setting and possibly more saline and colder upper boundary conditions. In this research, borehole data, electrical resistivity surveying, and modeling of heat and salt diffusion were carried out at Polar Fox Lagoon on the Bykovsky Peninsula, Siberia. Polar Fox Lagoon is a seasonally isolated water body connected to Tiksi Bay through a channel, leading to hypersaline waters under the ice cover. The boreholes in the center of the lagoon revealed floating ice and a saline cryotic bed underlain by a saline cryotic talik, a thin ice-bearing permafrost layer, and unfrozen ground. The bathymetry showed that most of the lagoon had bedfast ice in spring. In bedfast ice areas, the electrical resistivity profiles suggested that an unfrozen saline layer was underlain by a thick layer of refrozen talik. The modeling showed that thermokarst lake taliks can refreeze when submerged in saltwater with mean annual bottom water temperatures below or slightly above 0°C. This occurs, because the top-down chemical degradation of newly formed ice-bearing permafrost is slower than the refreezing of the talik. Hence, lagoons may precondition taliks with a layer of ice-bearing permafrost before encroachment by the sea, and this frozen layer may act as a cap on gas migration out of the underlying talik.

show abstract

“…The total thaw depth (talik depth ∼32 m, altitude difference between lake and Yedoma uplands ∼20 m) of ∼52 m is relatively shallow for 8000 years of thermokarst development (M. Angelopoulos, personal communication, 2020). Previous talik modeling studies of Alaskan thermokarst lakes showed faster talik growth rates for lakes in North America (e.g., Ling and Zhang, 2003;West and Plug, 2008;Kessler et al, 2012;Creighton et al, 2018). However, talik growth could be slowed by characteristics of Siberian Yedoma, such as its higher ice volume in these sediments or the presence of bedfast ice during an extended shallow lake phase (<2 m).…”

Section: Unit Iii/unit a -Yedoma Deposition Under Cold-dry Conditionsmentioning

confidence: 94%

n-Alkane Characteristics of Thawed Permafrost Deposits Below a Thermokarst Lake on Bykovsky Peninsula, Northeastern Siberia

Jongejans

Mangelsdorf

Schirrmeister

et al. 2020

Front. Environ. Sci.

View full text Add to dashboard Cite

Rapid permafrost thaw by thermokarst mobilizes previously frozen organic matter (OM) down to tens of meters deep within decades to centuries, leading to microbial degradation and greenhouse gas release. Late Pleistocene ice-rich Yedoma deposits that thaw underneath thermokarst lakes and refreeze after lake drainage are called taberal sediments. Although widespread, these have not been the subject of many studies. To study OM characteristics and degradability in thawed Yedoma, we obtained a 31.5 m long core from beneath a thermokarst lake on the Bykovsky Peninsula, northeastern Siberia. We reported radiocarbon ages, biogeochemical parameters [organic carbon (OC) content and bulk carbon isotopes] and n-alkane distributions. We found the most degraded OM in frozen, fluvial sediments at the bottom of the core, as indicated by the lowest n-alkane odd-over-even predominance (OEP; 2.2). Above this, the thawed Yedoma sediments had an n-alkane distribution typical of emergent vegetation, suggesting a landscape dominated by low-centered polygons. These sediments were OC poor (OC content: 0.8 wt%, 60% of samples < 0.1 wt%), but the OM (OEP∼5.0) was better preserved than in the fluvial sediments. The upper part of the Yedoma reflected a transition to a drier, grass dominated environment. Furthermore, this unit's OM was least degraded (OEP∼9.4). The thermokarst lake that formed about 8 cal ka BP thawed the Yedoma in the talik and deposited Holocene lake sediments containing well-preserved OM (OEP∼8.4) with the highest n-alkane concentrations (20.8 µg g −1 sediment). Old, allochthonous OM was found in the thawed Yedoma and frozen fluvial deposits. Using an n-alkane endmember model, we identified a mixed OM input in all units. In our study, the thawed Yedoma sediments contained less OC than reported in other studies for still frozen Yedoma. The Yedoma OM was more degraded compared to previous biomarker research on frozen Yedoma. However, this signal is

show abstract

Transient Electromagnetic Surveys for the Determination of Talik Depth and Geometry Beneath Thermokarst Lakes

Cited by 24 publications

References 79 publications

Seasonal Subsurface Thaw Dynamics of an Aufeis Feature Inferred From Geophysical Methods

Seasonal Subsurface Thaw Dynamics of an Aufeis Feature Inferred From Geophysical Methods

Thermokarst Lake to Lagoon Transitions in Eastern Siberia: Do Submerged Taliks Refreeze?

n-Alkane Characteristics of Thawed Permafrost Deposits Below a Thermokarst Lake on Bykovsky Peninsula, Northeastern Siberia

Contact Info

Product

Resources

About