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Late glacial and holocene sedimentation, vegetation, and climate history from easternmost Beringia (northern Yukon Territory, Canada)
- Beringian climate and environmental history are poorly characterized at its easternmost edge. Lake sediments from the northern Yukon Territory have recorded sedimentation, vegetation, summer temperature and precipitation changes since similar to 16 cal ka BP. Herb-dominated tundra persisted until similar to 14.7 cal ka BP with mean July air temperatures <= 5 degrees C colder and annual precipitation 50 to 120 mm lower than today. Temperatures rapidly increased during the Bolling/Allerod interstadial towards modern conditions, favoring establishment of Betula-Salix shrub tundra. Pollen-inferred temperature reconstructions recorded a pronounced Younger Dryas stadial in east Beringia with a temperature drop of similar to 1.5 degrees C (similar to 2.5 to 3.0 degrees C below modern conditions) and low net precipitation (90 to 170 mm) but show little evidence of an early Holocene thermal maximum in the pollen record. Sustained low net precipitation and increased evaporation during early Holocene warming suggest a moisture-limited spread ofBeringian climate and environmental history are poorly characterized at its easternmost edge. Lake sediments from the northern Yukon Territory have recorded sedimentation, vegetation, summer temperature and precipitation changes since similar to 16 cal ka BP. Herb-dominated tundra persisted until similar to 14.7 cal ka BP with mean July air temperatures <= 5 degrees C colder and annual precipitation 50 to 120 mm lower than today. Temperatures rapidly increased during the Bolling/Allerod interstadial towards modern conditions, favoring establishment of Betula-Salix shrub tundra. Pollen-inferred temperature reconstructions recorded a pronounced Younger Dryas stadial in east Beringia with a temperature drop of similar to 1.5 degrees C (similar to 2.5 to 3.0 degrees C below modern conditions) and low net precipitation (90 to 170 mm) but show little evidence of an early Holocene thermal maximum in the pollen record. Sustained low net precipitation and increased evaporation during early Holocene warming suggest a moisture-limited spread of vegetation and an obscured summer temperature maximum. Northern Yukon Holocene moisture availability increased in response to a retreating Laurentide Ice Sheet, postglacial sea level rise, and decreasing summer insolation that in turn led to establishment of Alnus-Berula shrub tundra from similar to 5 cal ka BP until present, and conversion of a continental climate into a coastal-maritime climate near the Beaufort Sea.…
Verfasserangaben: | Michael FritzORCiDGND, Ulrike HerzschuhORCiDGND, Sebastian WetterichORCiD, Hugues LantuitORCiDGND, Gregory P. De Pascale, Wayne H. Pollard, Lutz SchirrmeisterORCiDGND |
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DOI: | https://doi.org/10.1016/j.yqres.2012.07.007 |
ISSN: | 0033-5894 |
Titel des übergeordneten Werks (Englisch): | Quaternary research : an interdisciplinary journal |
Verlag: | Elsevier |
Verlagsort: | San Diego |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2012 |
Erscheinungsjahr: | 2012 |
Datum der Freischaltung: | 26.03.2017 |
Freies Schlagwort / Tag: | Holocene thermal maximum; Lake sediments; Laurentide Ice Sheet; Modern analogue technique; Pollen; Precipitation reconstruction; Temperature reconstruction; Trout Lake; WAPLS; Younger Dryas |
Band: | 78 |
Ausgabe: | 3 |
Seitenanzahl: | 12 |
Erste Seite: | 549 |
Letzte Seite: | 560 |
Fördernde Institution: | German Science Foundation (DFG) [LA 2399/3-1]; International Bureau of the German Federal Ministry of Education and Research (BMBF) [CAN 08/A07, CAN 09/001]; German Federal Environmental Foundation (DBU) |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer Review: | Referiert |