LLapointe_Elrabti

Lyna Lapointe-Elmrabti

Director : Julie Talbot
Codirector: Daniel Fortier

Primary Address:
Department of Geography
Strathcona Building, Room 204
Université de Montréal
520 chemin de la Côte-Sainte-Catherine
Montréal, Qc, Canada, H2V 2B8

Email Adress : lyna.lapointe.elmrabti@gmail.com
https://sites.google.com/site/biogeomontreal/

 

Project Tile

Apparent climate and ecological change during MIS 3-MIS 2 in northern Alaska, Itkillik River Yedoma

 

Description of the project research

The cold-arid climate associated to the late Pleistocene environment of unglaciated Beringia was favorable for active sedimentation processes (mainly eolian) and accumulation of ground ice. These processes resulted in the formation of an uniquetype of ice-rich syngenetic permafrost, termed yedoma. Yedoma deposits, as accumulated during MIS 4-MIS 2, contain a unique paleoenvironmental archive. This offers an opportunity to study long-term vegetation and climate dynamics of high-latitude environments. Often fragmented, data obtained from yedoma can be linked to the archive from other deposits (lake, pond, peatland sequences) and provide snapshots of an older period. Potentially, it can be linked to marine sequences and compared to northeastern Russia studies, were the distribution of yedoma deposits is more widespread. Knowing that Beringia has been a refugium for plant species and the megafauna during the Pleistocene, questions remain about the environmental history of northeastern Beringia, especially the extent and temporal dynamics of the former tundra-steppe biome.

The yedoma exposure atfrom the Itkillik River (69°34′ N, 150°52′ W) is located at the border of the Arctic Coastal Plain and the Arctic Foothills. The site was formed over the late Pleistocene-early Holocene (48,000 to 5,000 14C yr BP). The exposure, about 400 m long, has been eroded by the Itkillik River. The bluff height ranges between 30 to 35 m above river level. Pollen analysis and reconstruction of paleoclimatic parameters such as temperature and precipitation (modem analogue technique and δ18O) reveal a tundra-steppe environment dominated by herbaceous community. Implications of our findings for vegetation and local climate reconstructions using pollen-climate transfer functions are discussed and linked to the sedimentological and biogeochemical records (carbon content, carbon/nitrigen ratio, particle size distribution, etc.), and cryostratigraphy (cryostructure, volumetric ice content, ice wedge volume).

 

Key-words
Paleoecology, Paleoclimate, Pleistocene, Syngenetic permafrost, Carbon

 

Scholarships and other awards

2013 : Northern Scientific Training Program (NSTP)

2014 : Northern Scientific Training Program (NSTP)

 

Affiliations

Centre for Northern Studies (CEN)

Arctic Net

Laboratoire de biogéographie, Université de Montréal

 

 

 

 

 

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