thumbnail

Methane in permafrost - Preliminary results from coring at Fairbanks, Alaska

By:  and 

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core

Abstract

Permafrost has been suggested as a high-latitude source of methane (a greenhouse gas) during global warming. To begin to assess the magnitude of this source, we have examined the methane content of permafrost in samples from shallow cores (maximum depth, 9.5m) at three sites in Fairbanks, Alaska, where discontinuous permafrost is common. These cores sampled frozen loess, peat, and water (ice) below the active layer. Methane contents of permafrost range from <0.001 to 22.2mg/kg of sample. The highest methane content of 22.2mg/kg was found in association with peat at one site. Silty loess had high methane contents at each site of 6.56, 4.24, and 0.152mg/kg, respectively. Carbon isotopic compositions of the methane (??13C) ranged from -70.8 to -103.9 ???, and hydrogen isotopic compositions of the methane (??D) from -213 to -313 ???, indicating that the methane is microbial in origin. The methane concentrations were used in a one dimensional heat conduction model to predict the amount of methane that will be released from permafrost worldwide over the next 100 years, given two climate change scenarios. Our results indicate that at least 30 years will elapse before melting permafrost releases important amounts of methane; a maximum methane release rate will be about 25 to 30 Tg/yr, assuming that methane is generally distributed in shallow permafrost as observed in our samples.
Publication type Conference Paper
Publication Subtype Conference Paper
Title Methane in permafrost - Preliminary results from coring at Fairbanks, Alaska
Volume 26
Issue 1-4
Year Published 1993
Language English
Larger Work Title Chemosphere
First page 609
Last page 616
Google Analytic Metrics Metrics page
Additional publication details