Yukon Dust from Source to Sink: Characterizing the St. Elias Mountains as a High-Latitude Dust Source

Author (Your Name)

Audrey Y. Lemoine, Colby CollegeFollow

Date of Award

2025

Document Type

Honors Thesis (Open Access)

Department

Colby College. Geology Dept.

Advisor(s)

Bess Koffman

Second Advisor

Evan Dethier

Third Advisor

James King

Abstract

High-latitude dust is an important, yet poorly understood, component of Earth’s climate system. It impacts weather and albedo by acting as cloud condensation nuclei, directly affects Earth’s radiative balance, and can enhance productivity by supplying nutrients to ecosystems. In order to better understand high-latitude dust dynamics and impacts, we sampled glacial meltwater, surface sediment, and Holocene loess in the Łhù’ààn Mân (Kluane Lake) region of the Yukon Territory, Canada. We found that suspended sediment concentration is correlated with average slope and glaciation within a catchment, and is influenced by river morphology. We present new εNd and ⁸⁷Sr/⁸⁶Sr values that define a broader isotopic field than previously measured in the Yukon Territory, and demonstrate a strong relationship between average bedrock age and εNd on a catchment-by-catchment basis throughout the St. Elias Mountains. Our ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb data further define the provenance fingerprint and provide evidence of Asian pollution aerosols in the Yukon Territory. Altogether, these data add to a growing catalog of high-latitude dust-producing regions, offering insights into dust dynamics and transport patterns in the region.

Keywords

dust provenance, pollution, meltwater, suspended sediment, iron, isotopes

Recommended Citation

Lemoine, Audrey Y., "Yukon Dust from Source to Sink: Characterizing the St. Elias Mountains as a High-Latitude Dust Source" (2025). Honors Theses. Paper 1504.
https://digitalcommons.colby.edu/honorstheses/1504