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Methane emission by bubbling from Gatun Lake, PanamaWe studied methane emission by bubbling from Gatun Lake, Panama, at water depths of less than 1 m to about 10 m. Gas bubbles were collected in floating traps deployed during 12- to 60-hour observation periods. Comparison of floating traps and floating chambers showed that about 98% of methane emission occurred by bubbling and only 2% occurred by diffusion. Average methane concentration of bubbles at our sites varied from 67% to 77%. Methane emission by bubbling occurred episodically, with greatest rates primarily between the hours of 0800 and 1400 LT. Events appear to be triggered by wind. The flux of methane associated with bubbling was strongly anticorrelated with water depth. Seasonal changes in water depth caused seasonal variation of methane emission. Bubble methane fluxes through the lake surface into the atmosphere measured during 24-hour intervals were least (10-200 mg/m2/d) at deeper sites (greater than 7 m) and greatest (300-2000 mg/m2/d) at shallow sites (less than 2 m).
Document ID
19950029712
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Keller, Michael (Nation Center for Atmospheric Research, Boulder, CO United States)
Stallard, Robert F. (U. S. Geological Survey, Denver, CO United States)
Date Acquired
August 16, 2013
Publication Date
April 20, 1994
Publication Information
Publication: Journal of Geophysical Research
Volume: 99
Issue: D4
ISSN: 0148-0227
Subject Category
ENVIRONMENT POLLUTION
Funding Number(s)
CONTRACT_GRANT: NAGW-833
Distribution Limits
Public
Copyright
Other