Ryan Ellis,  

Sponsor or Client: 

Title:

Recent Warming in Context of the Past 500 Years at Salmon Lake, Alaska

Abstract:

This research utilizes a sediment record from Salmon Lake, Alaska, to reconstruct environmental changes over approximately 500 years to better understand glacier responses to regional shifts. It employs a multi-proxy approach, including BSi (Biogenic Silica), PSA (Particle Size Analysis), and XRF (X-Ray Fluorescence) analyses, alongside temperature and precipitation data from Nome, Alaska. We analyzed 64 core samples from the EN22501 surface core using a spectrophotometer and laser diffraction particle size analyzer. Based on the current age model developed from Northeastern University, diatom abundance increases since the 19th century, potentially indicating heightened lake productivity due to temperature rise, reduced ice cover, or increased nutrient delivery. Temperature rise correlates strongly with increased BSi, while precipitation shows a less consistent increase since 1900. XRF data suggest increased nutrient delivery, with notable changes in BSi, silica, and calcium around the Industrial Revolution, indicating possible anthropogenic influence. This study enhances understanding of past and present environmental conditions, shedding light on lake processes and their sensitivity to external factors, particularly human-induced changes.