In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems

Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of per...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: M. A. Kass, T. P. Irons, B. J. Minsley, N. J. Pastick, D. R. N. Brown, B. K. Wylie
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2017
Subjects:
geo
Ice
Online Access:https://doi.org/10.5194/tc-11-2943-2017
https://www.the-cryosphere.net/11/2943/2017/tc-11-2943-2017.pdf
https://doaj.org/article/08b8960fb56342759a2368a39c6da6e2
Description
Summary:Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example) geophysical investigations, ecological characterization, direct observations, remote sensing, and more. As part of a multiyear investigation into the impacts of wildfires on permafrost, we have collected in situ measurements of the nuclear magnetic resonance (NMR) response of the active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes and show the efficacy of borehole NMR (bNMR) to permafrost studies. Through statistical analyses and synthetic freezing simulations, we also demonstrate that borehole NMR is sensitive to the nucleation of ice within soil pore spaces.