Late glacial–Younger Dryas climate in interior Alaska as inferred from the isotope values of land snail shells

Quaternary Research
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Abstract

The isotope values of fossil snail shells can be important archives of climate. Here, we present the first carbon (δ13C) and oxygen (δ18O) isotope values of snail shells in interior Alaska to explore changes in vegetation and humidity through the late-glacial period. Snail shell δ13C values were relatively consistent through the late glacial. However, late-glacial shell δ13C values are 2.8‰ higher than those of modern shells. This offset is best explained by the Suess effect and changes in the δ13C values of snail diet. Snail shell δ18O values varied through the late glacial, which can be partially explained by changes in relative humidity (RH). RH during the snail growing period was modeled based on a published flux balance model. Results suggest a dry period toward the beginning of the Bølling–Allerød (~14 ka) followed by two distinct stages of the Younger Dryas, a wetter stage in the early Younger Dryas from 12.9 to 12.3 ka, and subsequent drier stage in the late Younger Dryas between 12.3 and 11.7 ka. The results show that land snail isotopes in high-latitude regions may be used as a supplementary paleoclimate proxy to help clarify complex climate histories, such as those of interior Alaska during the Younger Dryas.

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Publication type Article
Publication Subtype Journal Article
Title Late glacial–Younger Dryas climate in interior Alaska as inferred from the isotope values of land snail shells
Series title Quaternary Research
DOI 10.1017/qua.2023.54
Volume 117
Year Published 2024
Language English
Publisher Cambridge University Press
Contributing office(s) Geosciences and Environmental Change Science Center
Description 16 p.
First page 119
Last page 134
Country United States
State Alaska
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