Thermokarst lake methanogenesis along a complete talik profile

Heslop, Joanne; Anthony, K. M. Walter; Sepulveda‐Jauregui, Armando; Martinez‐Cruz, Karla; Bondurant, Allen C.; Grosse, Guido; Jones, Miriam C.

doi:10.5194/bg-12-4317-2015

Cited by 51 publications

(111 citation statements)

References 65 publications

(94 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two enrichment cultures derived from wetland sediments indicate higher Δ 18 values for a given CH 4 production rate than the pure culture experiments, possibly as a result of higher values of r rev or the occurrence of anaerobic CH 4 oxidation ( Figure S1). The modeled relationship between r net and Δ 18 from the pure cultures spans a plausible range of values for northern lakes, based on CH 4 production rates from incubation experiments of thermokarst lake sediments (Heslop et al, 2015) (Figure 1). Although there is uncertainty in quantitatively relating Δ 18 to CH 4 production rates in environmental samples, we propose that Δ 18 values can be used as an indicator of relative differences in CH 4 production rates between samples.…”

Section: Clumped Isotope Values In Culture Experiments Reflect Ch 4 Pmentioning

confidence: 99%

Clumped Isotopes Link Older Carbon Substrates With Slower Rates of Methanogenesis in Northern Lakes

Douglas

Moguel

Anthony

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

The release of long‐stored carbon from thawed permafrost could fuel increased methanogenesis in northern lakes, but it remains unclear whether old carbon substrates released from permafrost are metabolized as rapidly by methanogenic microbial communities as recently produced organic carbon. Here, we apply methane (CH4) clumped isotope (Δ18) and 14C measurements to test whether rates of methanogenesis are related to carbon substrate age. Results from culture experiments indicate that Δ18 values are negatively correlated with CH4 production rate. Measurements of ebullition samples from thermokarst lakes in Alaska and glacial lakes in Sweden indicate strong negative correlations between CH4 Δ18 and the fraction modern carbon. These correlations imply that CH4 derived from older carbon substrates is produced relatively slowly. Relative rates of methanogenesis, as inferred from Δ18 values, are not positively correlated with CH4 flux estimates, highlighting the likely importance of environmental variables other than CH4 production rates in controlling ebullition fluxes.

show abstract

Section: Clumped Isotope Values In Culture Experiments Reflect Ch 4 Pmentioning

confidence: 99%

Clumped Isotopes Link Older Carbon Substrates With Slower Rates of Methanogenesis in Northern Lakes

Douglas

Moguel

Anthony

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…The entrance to the VC tunnel is secured by a 30-m-long steel tube, which makes the uppermost part of the section inaccessible. The VC tunnel was also studied as a reference site for thermokarst lake methanogenesis by Heslop et al (2015).…”

Section: Study Areamentioning

confidence: 99%

Late Quaternary paleoenvironmental records from the Chatanika River valley near Fairbanks (Alaska)

Schirrmeister

Meyer

Andreev

et al. 2016

Quaternary Science Reviews

View full text Add to dashboard Cite

a b s t r a c tPerennially-frozen deposits are considered as excellent paleoenvironmental archives similar to lacustrine, deep marine, and glacier records because of the long-term and good preservation of fossil records under stable permafrost conditions. A permafrost tunnel in the Vault Creek Valley (Chatanika River Valley, near Fairbanks) exposes a sequence of frozen deposits and ground ice that provides a comprehensive set of proxies to reconstruct the late Quaternary environmental history of Interior Alaska. The multi-proxy approach includes different dating techniques (radiocarbon-accelerator mass spectrometry [AMS 14 The studied sequence consists of 36-m-thick late Quaternary deposits above schistose bedrock. Main portions of the sequence accumulated during the early and middle Wisconsin periods. The lowermost unit A consists of about 9-m-thick ice-bonded fluvial gravels with sand and peat lenses. A late Sangamon (MIS 5a) age of unit A is assumed. Spruce forest with birch, larch, and some shrubby alder dominated the vegetation. High presence of Sphagnum spores and Cyperaceae pollen points to mires in the Vault Creek Valley. The overlying unit B consists of 10-m-thick alternating fluvial gravels, loess-like silt, and sand layers, penetrated by small ice wedges. OSL dates support a stadial early Wisconsin (MIS 4) age of unit B. Pollen and plant macrofossil data point to spruce forests with some birch interspersed with wetlands around the site. The following unit C is composed of 15-m-thick ice-rich loess-like and organic-rich silt with fossil bones and large ice wedges. Unit C formed during the interstadial mid-Wisconsin (MIS 3) and stadial late Wisconsin (MIS 2) as indicated by radiocarbon ages. Post-depositional slope processes significantly deformed both, ground ice and sediments of unit C. Pollen data show that spruce forests and wetlands dominated the area. The macrofossil remains of Picea, Larix, and Alnus incana ssp. tenuifolia also prove the existence of boreal coniferous forests during the mid-Wisconsin interstadial, which were replaced by treeless tundra-steppe vegetation during the late Wisconsin stadial. Unit C is discordantly overlain by the 2-m-thick late Holocene deposits of unit D. The pollen record of unit D indicates boreal forest vegetation similar to the modern one.The permafrost record from the Vault Creek tunnel reflects more than 90 ka of periglacial landscape dynamics triggered by fluvial and eolian accumulation, and formation of ice-wedge polygons and postdepositional deformation by slope processes. The record represents a typical Wisconsin valley-bottom facies in Central Alaska.

show abstract

“…In contrast, ancient yedoma carbon is decomposed throughout the sediment profile (Fig. 1), with particularly high rates of methanogenesis occurring along the permafrost thaw front, located deep in the thaw bulb beneath the lake (Heslop et al, 2015). Methane produced at depth in the thaw bulb subsequently migrates, primarily as free-phase bubbles through bubble tubes in sediments, to the surface sediments where it escapes the lake via ebullition (Walter Anthony and Anthony, 2013;Tan et al 2015).…”

Section: Geographic and Seasonal Variations In Physicochemical Paramementioning

confidence: 99%

Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

et al. 2015

Self Cite

View full text Add to dashboard Cite

Abstract. Methanotrophic bacteria play an important role oxidizing a significant fraction of methane (CH 4 ) produced in lakes. Aerobic CH 4 oxidation depends mainly on lake CH 4 and oxygen (O 2 ) concentrations, in such a manner that higher MO rates are usually found at the oxic/anoxic interface, where both molecules are present. MO also depends on temperature, and via methanogenesis, on organic carbon input to lakes, including from thawing permafrost in thermokarst (thaw)-affected lakes. Given the large variability in these environmental factors, CH 4 oxidation is expected to be subject to large seasonal and geographic variations, which have been scarcely reported in the literature. In the present study, we measured CH 4 oxidation rates in 30 Alaskan lakes along a north-south latitudinal transect during winter and summer with a new field laser spectroscopy method. Additionally, we measured dissolved CH 4 and O 2 concentrations. We found that in the winter, aerobic CH 4 oxidation was mainly controlled by the dissolved O 2 concentration, while in the summer it was controlled primarily by the CH 4 concentration, which was scarce compared to dissolved O 2 . The permafrost environment of the lakes was identified as another key factor. Thermokarst (thaw) lakes formed in yedoma-type permafrost had significantly higher CH 4 oxidation rates compared to other thermokarst and non-thermokarst lakes formed in non-yedoma permafrost environments. As thermokarst lakes formed in yedoma-type permafrost have been identified to receive large quantities of terrestrial organic carbon from thaw and subsidence of the surrounding landscape into the lake, confirming the strong coupling between terrestrial and aquatic habitats and its influence on CH 4 cycling.

show abstract

Thermokarst lake methanogenesis along a complete talik profile

Cited by 51 publications

References 65 publications

Clumped Isotopes Link Older Carbon Substrates With Slower Rates of Methanogenesis in Northern Lakes

Clumped Isotopes Link Older Carbon Substrates With Slower Rates of Methanogenesis in Northern Lakes

Late Quaternary paleoenvironmental records from the Chatanika River valley near Fairbanks (Alaska)

Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

Contact Info

Product

Resources

About