Isotopic composition of ground ice, ebullition gases and thermokarst lake water, Alaska, 2008-2010

Brosius, Laura Susan; Walter Anthony, Katey M; Grosse, Guido; Chanton, Jeffrey P; Farquharson, Louise M; Overduin, Pier Paul; Meyer, Hanno

Thermokarst lakes are thought to have been an important source of methane (CH4) during the last deglaciation when atmospheric CH4 concentrations increased rapidly. Here we demonstrate that meltwater from permafrost ice serves as an H source to CH4 production in thermokarst lakes, allowing for region-specific reconstructions of dD-CH4 emissions from Siberian and North American lakes. dD CH4 reflects regionally varying dD values of precipitation incorporated into ground ice at the time of its formation. Late Pleistocene-aged permafrost ground ice was the dominant H source to CH4 production in primary thermokarst lakes, whereas Holocene-aged permafrost ground ice contributed H to CH4 production in later generation lakes. We found that Alaskan thermokarst lake dD-CH4 was higher (-334 ± 17 per mil) than Siberian lake dD-CH4 (-381 ± 18 per mil). Weighted mean dD CH4 values for Beringian lakes ranged from -385 per mil to -382 per mil over the deglacial period. Bottom-up estimates suggest that Beringian thermokarst lakes contributed 15 ± 4 Tg CH4 /yr to the atmosphere during the Younger Dryas and 25 ± 5 Tg CH4 /yr during the Preboreal period. These estimates are supported by independent, top-down isotope mass balance calculations based on ice core dD-CH4 and d13C-CH4 records. Both approaches suggest that thermokarst lakes and boreal wetlands together were important sources of deglacial CH4.

Zitierung

Bei Verwendung dieser Daten, müssen Sie diesen Datensatz mit einer der folgenden Quellenangaben zitieren:

Kontakt

Laura Susan Brosius

Metadaten-Zugang

DCAT in RDF/XML-Format

DCAT in Turtle-Format

DCAT in JSON-LD-Format

APGC Dataset Metadata in JSON-Format

Daten und Ressourcen

Zusätzliche Informationen

Feld Wert
Identifikator DOI: 10.1594/PANGAEA.808037
Projekt(e) International Polar Year (2007-2008) (IPY)
Institut University of Alaska, Fairbanks
Quelle https://doi.pangaea.de/10.1594/PANGAEA.808037
Publikationsdatum 2012
Version 1.0
Produkt δ Deuterium and δ13C methane of thermokarst lake ebullition gases and water
Sensor(en) GC and Delta V isotope ratio mass spectrometer
Dateien
  1. Brosius_2012.zip
  2. Alaska_isotope-ice.tab
  3. Alaska_isotope-gas-water.tab
Variablen [Einheiten]
  1. Event: Event label
  2. Area: Area/locality
  3. Epoch: Epoch
  4. Age max [ka]: Maximum age [ka]
  5. Age min [ka]: Minimum age [ka]
  6. δD H2O [‰ SMOW] (min): minimum δ deuterium water
  7. δD H2O [‰ SMOW] (mean): mean δ deuterium water
  8. δD H2O [‰ SMOW] (max): maximum δ deuterium water
  9. δ18O H2O [‰ SMOW] (min): minimum δ18O water [‰ SMOW]
  10. δ18O H2O [‰ SMOW] (mean): mean δ18O water [‰ SMOW]
  11. δ18O H2O [‰ SMOW] (max): maximum δ18O water [‰ SMOW]
  12. Description (seep generation): Description of seep generation
  13. No (of seeps): Number of seeps
  14. Bathy depth [m] (average depth): bathymetric depth [m]
  15. δD CH4 [‰ SMOW]: δ Deuterium, methane [‰ SMOW]
  16. δD std dev [±] (d2H-CH4): δ Deuterium, standard deviation [±]
  17. δ13C CH4 [‰ PDB]: δ13C, methane [‰ PDB]
  18. δ13C CH4 std dev [±]: δ13C, methane, standard deviation [±]
  19. δ13C CO2 aq [‰]: δ13C, carbon dioxide, aquatic [‰]
  20. δ13C CO2 std dev [±]: δ13C, carbon dioxide, standard deviation [±]
Region Alaska
Räumlicher Bezug
Räumliche Auflösung Point based
Räumliche Abdeckung Latitude 60.0908 to 62.4553, Longitude -135.6598 to -114.5322
Zeitliche Abdeckung 2008 - 2010
Zeitliche Auflösung Discrete
Format ZIP, CSV
Is Supplement To

Brosius, LS et al. (2012): Using the deuterium isotope composition of permafrost meltwater to constrain thermokarst lake contributions to atmospheric CH4 during the last deglaciation. Journal of Geophysical Research: Biogeosciences, 117(G1), G01022, https://doi.org/10.1029/2011JG001810

Zusammenhang mit

Ausdehnung des Datensatzes