iSPEAC (invited Speakers in Physics, Environmental science, And Chemistry) is the Department of Physical and Environmental Science’s invited speaker series, which covers topics and is delivered by external experts and academics in physics, environmental science, and chemistry.  Speakers from near and far are invited to share their cutting-edge research with an interdisciplinary audience of students, faculty and staff.  The series is co-sponsored by the Department of Physical and Environmental Science, and the Office of the Vice-Principal Research at UTSC. 

Tuesday Jan 16, 2018 Time: 3PM-4pm  Room: EV140
Professor Greg Slater, McMaster University

"Investigating the Role of Microbial Carbon Cycling in Contaminated Systems"

Research Interests: Stable Isotope Geochemistry, Environmental and Organic Geochemistry, Geobiology, Contaminant Hydrogeology, Biodegradation and Bioremediation, Astrobiology

Thursday Feb 15, 2018 Time: 3PM-4PM Room: EV140

Dr Jeroen Sonke

"Mercury stable isotope biogeochemistry - Exploration, application and opportunities"

2019 will mark the 100th aniversary of the discovery of Hg stable isotopes by Sir Francis Aston. Early attempts in the 1920s to detect variations in the Hg isotope abundances of natural Hg by precise density measurements were unlucky. The field had to await the 21st century for the first modern mass spectrometric evidence for large (10 per mil) mass dependent and mass independent Hg isotope fractionation. In this presentation I will reflect on nearly two decades of modern Hg isotope exploration. Studies in the fields of biogeochemistry, atmospheric chemistry, and paleogeochemistry will be highlighted. Exploration is now giving way to hypothesis-driven studies and novel applications to challening problems in Hg science; I will briefly discuss breakthroughs in our understanding of atmospheric Hg deposition pathways.

Tusday Feb 20, 2018 Time: 3PM-4pm  Room: EV140

Professor Nelson O’Driscoll, Acadia University

"Wetland restoration, biovectors and mercury cycling: A story of human disturbance"

Big Meadow Bog (Brier Island, Nova Scotia, Canada) is a wetland ecosystem with a history of human disturbance. It was ditched for small-scale blueberry production in the 1950s, which significantly altered the hydrology of the system and resulted in vegetation changes and colonization by 3000+ pairs of herring gulls by the 1980s. The blueberry venture never materialized. This talk will provide an overview of the history of this site and the complex effects of the hydrological and ecological changes on mercury cycling. Mercury is a persistent and bioaccumulative chemical that is present in many remote environments due to its ability to be transported long distances in the atmosphere. Wetland ecosystems are important “hot spots” for mercury in eastern Canada, providing anoxic environmental conditions that promote the bacterial methylation of mercury. Methyl mercury is the most biologically available form of mercury and the form which biomagnifies in food webs. Seabird guano is a well-documented biovector for metals (including mercury) and nutrients, which may indirectly affect mercury speciation. Our results show significantly higher phosphate and methyl mercury concentrations in shallow surface water in Big Meadow Bog, compared to reference bog sites that are minimally impacted by avian biovectors. Big Meadow Bog is currently undergoing restoration to reverse the effects of the ditching and re-establish an endangered plant species; these changes will likely again alter the presence of biovectors and ultimately the fate of mercury in the system.

Research Interests: Quantifying environmental processes that control the fate of mercury and other toxic chemicals in ecosystems

Friday March 9, 2018 Time: 1:30PM-2:30PM Room: EV140
Professor Jay Austin University of Minnesota Duluth

Research Interests: Physical Limnology and Oceanography

Wednesday March 14, 2018 Time:3PM-4PM Room: EV140
Professor Debra Wunch, University of Toronto

Research Interests: Impact of the Boreal forest on the global carbon cycle, and the magnitude of the greenhouse gas emissions from Toronto, Canada's largest city

TBA April Room: EV140
Professor Derek Wilson, York University

Research Interests: Protein Dynamics, Microfluidics, Time-resolved Mass Spectrometry, Biophysical NMR

All students, faculty, and staff are welcome to attend!