A multi-proxy investigation of late-Holocene temperature change and climate-driven fluctuations in sediment sourcing: Simpson Lagoon, Alaska:

The significant and ongoing environmental changes in Arctic regions demonstrate the need for quantitative, high-resolution records of pre-industrial climate change in this climatically sensitive region; such records are fundamental for understanding recent anthropogenic changes in the context of natural variability. Sediment contained within Arctic coastal environments proximal to large fluvial systems has the ability to record paleoclimate variability on subdecadal to decadal scale resolution, on par with many other terrestrial climate archives (i.e. lake sediments, ice cores). Here, we utilize one such sediment archive from Simpson Lagoon, Alaska, located adjacent to the Colville River Delta to reconstruct temperature variability and fluctuations in sediment sourcing over the past 1700 years. Quantitative reconstructions of summer air temperature are obtained using the branched glycerol dialkyl glycerol tetraether (brGDGT)-derived methylation index of branched tetraethers (MBT’)/cyclization ratio of bra...