Page 148 - Microbial methane cycling in a warming world From biosphere to atmosphere Michiel H in t Zandt

Chapter 6. Roles of thermokarst lakes in a warming world
AOM - Anaerobic oxidation of methane. This process is performed by anaerobic methanotrophic archaea (ANME). The ANME are further subdivided into the clades ANME-1, ANME-2, and ANME-3.
Ebullition - A suddenly occurring flux of methane bubbles from sediments and water columns. These emissions are the result of methane building up over time, which leads to the formation of gas pockets that are released during bubbling events.
Functional gene - A region of DNA that contains the nucleotide sequence encoding a single protein with a function in an organism. These regions behave as single hereditary units. GWP - Global warming potential. This is a measure of the amount of heat that is trapped by a
greenhouse gas in the atmosphere within a specific time period. The number is expressed
relative to CO2, whose GWP is standardized to 1.
Lagoon - A shallow body of water that is separated from a larger body of water, for example
the sea, by barrier land or reefs. Water bodies separated by barrier land are called coastal
lagoons; those separated by reefs are called atoll lagoons.
Lithalsa - Frost-induced landscape elements that are elevated due to freeze-expansion effects
during ice lens formation. Upon partial thaw these bodies can form characteristic ring-like
structures.
MOB - Methane-oxidizing bacteria. These are bacteria that oxidize methane at the expense of
oxygen using the enzyme methane monooxygenase.
Palsa - Frost heaves that occur in permafrost landscapes with permanently frozen ice lenses.
They consist of a frozen ice core that is covered by a layer of soil. Palsas are comparable to
pingos, but they are generally smaller in size.
Pingo - Alternatively named ‘hydrolaccolith’ or ‘bulgunniakh’, pingos are frost heaves that
occur in permafrost landscapes with permanently frozen ice lenses. These heaves can reach
a height of up to 70 m and are much larger than palsas.
Q10 values - Temperature coefficient. A measure of the rate of change of a system as a result
of a temperature rise of 10°C.
Talik - Year-round unfrozen ground that occurs within permafrost, often below thermokarst
lakes, streams, and rivers.
Thermokarst - A landscape characterized by irregularities including hummocks and hollows
caused by the thaw of ice-rich permafrost.
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