Document Type

Article

Publication Title

Global Biogeochemical Cycles

Publication Date

1-7-2004

Issue Number

1

Publication Number

GB1003

Volume Number

18

Abstract/ Summary

Peatlands deform elastically during precipitation cycles by small (+/- 3 cm) oscillations in surface elevation. In contrast, we used a Global Positioning System network to measure larger oscillations that exceeded 20 cm over periods of 4 - 12 hours during two seasonal droughts at a bog and fen site in northern Minnesota. The second summer drought also triggered 19 depressuring cycles in an overpressured stratum under the bog site. The synchronicity between the largest surface deformations and the depressuring cycles indicates that both phenomena are produced by the episodic release of large volumes of gas from deep semi-elastic compartments confined by dense wood layers. We calculate that the three largest surface deformations were associated with the release of 136 g CH4 m(-2), which exceeds by an order of magnitude the annual average chamber fluxes measured at this site. Ebullition of gas from the deep peat may therefore be a large and previously unrecognized source of radiocarbon depleted methane emissions from northern peatlands.

Citation/Publisher Attribution

Glaser, PH, Chanton, JP, Morin, P, Rosenberry, DO, Siegel, DI, Ruud, O, Chasar, LI, et al., 2004, Surface Deformations as Indicators of Deep Ebullition Fluxes in a Large Northern Peatland: Global Biogeochemical Cycles, v. 18, GB1003. To view the published open abstract, go to http://dx.doi.org and enter the DOI.

Publisher Statement

© Copyright 2004 American Geophysical Union

DOI

10.1029/2003GB002069

Version

publisher's version of the published document

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