Undergraduate Honors Theses

Thesis Defended

Spring 2019

Document Type


Type of Thesis

Departmental Honors


Environmental Studies

First Advisor

Dale Miller

Second Advisor

Julio Sepúlveda

Third Advisor

Greg de Wet


This research study assesses the validity of bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs) for temperature reconstructions in Arctic settings from a sediment core extracted from Brother of Fog lake, Baffin Island. The distribution of brGDGTs in lake sediments have been shown to correlate with mean annual air temperature (MAAT) and serve as a proxy for paleotemperature reconstructions. This study aims to reconstruct temperature variability over the Holocene (~11500 years) and the applicability of this proxy for high latitude lakes. The results show a large bias within the brGDGT-inferred temperature reconstruction when applying the Russell et al. 2018 calibration. Due to the unintended nature of the temperature reconstruction, multiple confounding variables were accounted for to understand the environmental influences on the formation of brGDGTs. Overall, this research shows the potential effects that anoxic water columns have on brGDGT temperature signals from lacustrine sediment cores extracted from Brother of Fog Lake in Baffin Island.