Hydraulic reversals and episodic methane emissions during drought cycles in mires
- Syracuse Univ., NY (United States)
- Univ. of Minnesota, Minneapolis, MN (United States)
Reversals in hydraulic head and extensive methane losses were identified during a drought cycle from changes in hydraulic-head and dissolved-methane profiles in peat, Glacial Lake Agassiz Peatlands, northern Minnesota, United States. During the summer 1990 drought, regional groundwater discharged from the mineral soil underlying the peat to raised bogs. Concentrations of dissolved CH[sub 4] in pore water showed that much of the peat column was supersaturated with respect to a reference standard of 1 atm partial pressure CH[sub 4]. By the summer of 1991, the severity of the drought lessened, and the upper peat column was resaturated with precipitation-derived water. Groundwater flow was then controlled by local, precipitation-driven, recharge flow systems, and the regional groundwater that was discharged affected only the peat immediately above the mineral soil-peat interface. In contrast, during the summer of 1991, concentrations of dissolved CH[sub 4] in pore water were all undersaturated with respect to 1 atm partial pressure CH[sub 4]. 23 refs., 5 figs.
- DOE Contract Number:
- FG02-90ER60984
- OSTI ID:
- 7238290
- Journal Information:
- Geology; (United States), Journal Name: Geology; (United States) Vol. 21:3; ISSN 0091-7613; ISSN GLGYBA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010000* -- Coal
Lignite
& Peat
58 GEOSCIENCES
580000 -- Geosciences
ALKANES
AQUATIC ECOSYSTEMS
DEVELOPED COUNTRIES
DROUGHTS
ECOSYSTEMS
ENERGY SOURCES
FLUID MECHANICS
FOSSIL FUELS
FUELS
GROUND WATER
HYDRAULICS
HYDROCARBONS
HYDROGEN COMPOUNDS
INTERFACES
INTERSTITIAL WATER
MATTER
MECHANICS
METHANE
MINNESOTA
NORTH AMERICA
ORGANIC COMPOUNDS
ORGANIC MATTER
OXYGEN COMPOUNDS
PARTIAL PRESSURE
PEAT
PORE PRESSURE
POROSITY
SOILS
SWAMPS
TERRESTRIAL ECOSYSTEMS
USA
WATER
WETLANDS