1:00 pm - 2:00 pm
150 South Academic Building (SAB), South Academic Building, University of Alberta, Edmonton AB
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree. This is an ALES PhD Final Exam Seminar by Andrii Oleksandrenko. This seminar is open to the general public to attend.
Zoom Link: https://ualberta-ca.zoom.us/j/97977538618?pwd=nLeTe1M79U79tOdcabnUogPKsTGjFi.1
PhD with Dr. William Shotyk.
Thesis Topic: Americium-241 and trace elements in peat bogs as markers of the beginning of the Anthropocene
Abstract:
Peat bogs may serve as archives of atmospheric deposition of contaminants marking the start of the Anthropocene—the period of globally significant human impacts on the environment. Fallout radionuclides (e.g., ²⁴¹Am) and trace elements (TEs) such as lead (Pb) are potential markers of this epoch, but their preservation in acidic bogs required evaluation. In 35 peat cores, ²⁴¹Am peaks were detected in 22 cases, with 18 aligning within a decade of 1963, the zenith in open-air nuclear weapons testing. Lead in peat cores sampled 20 years apart is well preserved, while other TEs showed considerable differences over time. Comparing peat and porewater concentrations illustrates how well elements such as Pb are retained by the solid phase while other TEs are released to the porewaters. While ²⁴¹Am in bogs is a promising marker of the start of the Anthropocene, more sensitive analytical methods are needed for further study. Regarding TEs in bogs as markers of anthropogenic emissions to the atmosphere, the differential retention of elements by peat must be duly considered.
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