Date of Award

Spring 5-8-2020

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Physics

Advisor

C.T. Hess

Second Committee Member

Thomas Stone

Third Committee Member

Saima Farooq

Additional Committee Members

Andre Kahlil

George Bernhardt

Abstract

Radiometric dating is a common technique used to estimate the age of sediment and ice core samples. Lead-210 is widely used for dating sediment samples less than 150 years old. The two most commonly used lead-210 dating techniques rely on the assumption that the amount of lead-210 that is deposited in lake beds and other waterways remains constant over time. However, this assumption may not always be physically realistic, and if the rate is not constant, then age estimates derived using the constant rate assumption may not be accurate. A new dating technique allowing for non-constant lead-210 supply rates (the NCRS model) was developed. It was implemented on 34 different sediment samples. Of these samples, 10 exhibited apparent sinusoidal caluctuations. Discrepancies in age estimates between models were most pronounced for the upper sediment layers. For the data sets which varied sinusoidally, the period was also computed and analyzed.

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