The collapse of the Cordilleran–Laurentide ice saddle and early opening ofthe Mackenzie Valley, Northwest Territories, Canada, constrained by (10)Be exposure dating
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F22%3A10454401" target="_blank" >RIV/00216208:11310/22:10454401 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=DfGTqma_z4" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=DfGTqma_z4</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.5194/tc-16-4865-2022" target="_blank" >10.5194/tc-16-4865-2022</a>
Alternative languages
Result language
angličtina
Original language name
The collapse of the Cordilleran–Laurentide ice saddle and early opening ofthe Mackenzie Valley, Northwest Territories, Canada, constrained by (10)Be exposure dating
Original language description
Deglaciation of the northwestern Laurentide Ice Sheet in the central Mackenzie Valley opened the northern portion of the deglacial Ice-Free Corridor between the Laurentide and Cordilleran ice sheets and a drainage route to the Arctic Ocean. In addition, ice sheet saddle collapse in this section of the Laurentide Ice Sheet has been implicated as a mechanism for delivering substantial freshwater influx into the Arctic Ocean on centennial timescales. However, there is little empirical data to constrain the deglaciation chronology in the central Mackenzie Valley where the northern slopes of the ice saddle were located. Here, we present 30 new (10)Be cosmogenic nuclide exposure dates across six sites, including two elevation transects, which constrain the timing and rate of thinning and retreat of the Laurentide Ice Sheet in the area. Our new (10)Be dates indicate that the initial deglaciation of the eastern summits of the central Mackenzie Mountains began at approx. 15.8 ka (17.1-14.6 ka), approx. 1000 years earlier than in previous reconstructions. The main phase of ice saddle collapse occurred between approx. 14.9 and 13.6 ka, consistent with numerical modelling simulations, placing this event within the Bolling-Allerod interval (14.6-12.9 ka). Our new dates require a revision of ice margin retreat dynamics, with ice retreating more easterly rather than southward along the Mackenzie Valley. In addition, we quantify a total sea level rise contribution from the Cordilleran-Laurentide ice saddle region of approx. 11.2 m between 16 and 13 ka.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10508 - Physical geography
Result continuities
Project
<a href="/en/project/GJ19-21216Y" target="_blank" >GJ19-21216Y: New deglaciation chronology of the North American Ice Sheet Complex</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Cryosphere
ISSN
1994-0416
e-ISSN
1994-0424
Volume of the periodical
16
Issue of the periodical within the volume
12
Country of publishing house
DE - GERMANY
Number of pages
22
Pages from-to
4865-4886
UT code for WoS article
000894467200001
EID of the result in the Scopus database
2-s2.0-85145598412