Carbon and hydrogen isotopic characterization of methane from wetlands and lakes of the Yukon-Kuskokwim Delta, western Alaska ...

• Main Authors: Showers, W.J., Martens, C.S., Kelley, C.A., Chanton, J.P.
• Format: Text
• Language: English
• Published: Wiley-Blackwell 1992
• Subjects: Yukon; Kuskokwim; Tundra; Alaska
• Online Access: https://dx.doi.org/10.17615/dtff-dd02; https://cdr.lib.unc.edu/concern/articles/n583z4660

The total methane flux to the troposphere from tundra environments of the Yukon-Kuskokwim Delta is dominated by emissions from wet meadow tundra (~75%) and small, organic-rich lakes (~20%). The mean δ13C value of methane diffusing into collar-mounted flux chambers from wet meadow environments near Bethel, Alaska, was -65.82±2.21‰ (±1 sigma, n=18) for the period July 10 to August 10, 1988. A minimum ebullition estimated for the 5% of total Delta area comprised of small lakes ranges from 0.34 to 9.7 × 1010g Ch4yr-1, which represents 0.6% to 17% of the total Delta methane emission. The δ13C and δD values of this ebullitive flux are -61.41±2.46‰ (n=38) and -341.8±18.2‰ (n=21), respectively. The methane in gas bubbles from two lakes is of modern, bomb carbon enriched, radiocarbon age. Gas bubble δ13C values varied from 2 to 5‰ seasonally, reaching heaviest values in midsummer; no such variations in δD values were observed. ...