3D ground-penetrating radar imaging of ice complex deposits in northern East Siberia

Abstract

Ice complex deposits are characteristic, ice-rich formations in northern East Siberia and represent an important part in the arctic carbon pool. Recently, these late Quaternary deposits are the objective of numerous investigations typically relying on outcrop and borehole data. Many of these studies can benefit from a 3D structural model of the subsurface for upscaling their observations or for constraining estimations of inventories, such as the local carbon stock. We have addressed this problem of structural imaging by 3D groundpenetrating radar (GPR), which, in permafrost studies, has been primarily used for 2D profiling. We have used a 3D kinematic GPR surveying strategy at a field site located in the New Siberian Archipelago on top of an ice complex. After applying a 3D GPR processing sequence, we were able to trace two horizons at depths below 20 m. Taking available borehole and outcrop data into account, we have interpreted these two features as interfaces of major lithologic units and derived a 3D cryostratigraphic model of the subsurface. Our data example demonstrated that a 3D surveying and processing strategy was crucial at our field site and showed the potential of 3D GPR to image geologic structures in complex ice-rich permafrost landscapes.

Substrate potential of Eemian to Holocene permafrost organic matter for future microbial greenhouse gas production

“…Considering the thickness of the LP Yedoma deposit of 20 m on Bol'shoy Lyakhovsky Island (Schennen et al, 2016) and 10-60 m across Russia , and a Yedoma extension of about 106 km² (Romanovsky, 1993) a significant substrate pool for future microbial greenhouse gas generation within permafrost thawing is assessable. On a broader perspective, an ongoing Arctic 20 warming will increase active layer thickness and thus favour substrate availability from deeper and older OM for microbial decomposition which enhances the production and release of greenhouse gases (Schuur et al, 2008).…”

Substrate potential of last interglacial to Holocene permafrost organic matter for future microbial greenhouse gas production

“…Thus, as a consequence of Northern Hemisphere warming an increase in ground temperature, changes in soil drainage, deepening of the active layer (seasonally thawed surface layer), spatial retreat of permafrost, and changes in vegetation have already been reported for the Arctic (Davidson and Janssens, 2006;Anisimov, 2007;Romanovsky et al, 2010;Mueller et al, 2015). During permafrost formation low temperatures, anoxic soil conditions, and low rates of organic matter (OM) decomposition (Schimel and Schaeffer, 2012) result in high rates of OM accumulation (Kuhry et al, 2009;Zimov et al, 2009;Schirrmeister et al, 2011a). The currently observed thawing of permafrost promotes the accessibility of accumulated and freeze-locked OM and nutrients for microbial turnover.…”

Prospecting and Evaluation of Underground Massive Ice by Ground-Penetrating Radar

“…We chose the value ε = 4 for our study, which is without restriction, and all of the following formulas can be recalculated for any value ε necessary for the reader. Assume that the signal amplitude emitted by the GPR is equal to Ad, then according to [39] the amplitude of the wave reflected from the upper ice boundary will be equal to Aupper = AdR1-2 2 1 1 (1)…”

“…Assume that the signal amplitude emitted by the GPR is equal to A d , then according to [39] the amplitude of the wave reflected from the upper ice boundary will be equal to…”

“…The review [27] presents the positively proven geophysical methods. Currently, there is positive experience in studying vein ice [28][29][30][31][32][33][34], massive ice [35][36][37], zones of high ice content [17], pingo ice [38,39], and cave ice [40,41].…”