Sediment Characteristics and Methane Ebullition in Three Subarctic Lakes

Authors

Martin Wik, Stockholm University
Joel E. Johnson, University of New Hampshire, DurhamFollow
Patrick M. Crill, Stockholm University
Joel P. DeStasio, University of New Hampshire, Durham
Lance Erickson, University of New Hampshire, Durham
Madison J. Halloran, University of New Hampshire, Durham
Maria Florencia Fahnestock, University of New Hampshire, DurhamFollow
Maurice K. Crawford, University of Maryland Eastern Shore
Stephen C. Phillips, University of New Hampshire, Durham
Ruth K. Varner, University of New Hampshire, DurhamFollow

Abstract

Ebullition (bubbling) from climate‐sensitive northern lakes remains an unconstrained source of atmospheric methane (CH4). Although the focus of many recent studies, ebullition is rarely linked to the physical characteristics of lakes. In this study we analyze the sediments of subarctic postglacial lakes and investigate how sediment properties relate to the large spatial variation in CH4 bubble flux, quantified over multiple years using bubble traps. The results show that the sediments from our lakes are rich in total organic carbon, containing 37 kg/m3 on average. This number is roughly 40% higher than the average for yedoma deposits, which have been identified as high CH4 emitters. However, the quantity of total organic carbon is not a useful indicator of high emissions from the study lakes. Neither is the amount of CH4 in the sediment a reliable measure of ebullition potential. Instead, our data point to coarse detritus, partly from buried submerged aquatic vegetation and redeposited peat as spatial controls on fluxes, often in combination with previously established effects of incoming solar radiation and water depth. The results once again highlight the climate sensitivity of northern lakes, indicating that biological responses to warmer waters and increased energy input and heating of organic sediments during longer ice‐free seasons can substantially alter future CH4 emissions.

Department

Earth Systems Research Center, Earth Sciences

Publication Date

7-11-2018

Journal Title

Journal of Geophysical Research: Biogeosciences

Publisher

American Geophysical Union (AGU)

Digital Object Identifier (DOI)

https://dx.doi.org/10.1029/2017JG004298

Document Type

Article

Recommended Citation

Wik, M., J.E. Johnson, P.M. Crill, *J.P. DeStasio, *L. Erickson, *M.J. Halloran, °M. Florencia Fahnestock, M.K. Crawford, S.C. Phillips, and R.K. Varner (2018) Sediment characteristics and methane ebullition in three subarctic lakes, J. of Geophys. Res. Biogeosci., doi.org/10.1029/2017JG004298.

Rights

©2018. American Geophysical Union. All Rights Reserved.

Comments

This is an article published by AGU in Journal of Geophysical Research: Biogeosciences in 2018, available online: https://dx.doi.org/10.1029/2017JG004298