Johan Gilchrist and Kate Smith
Thursday, April 8, 2021 · 11:00 am
Virtual / Zoom
Hosted by
Philippe Tortell and Rachel White

Honey, let me tell you about this city! Honey as a biomonitor for lead distribution un urban environments

Kate Smith holds a BSc in Chemistry from Michigan Technological University (2008) and a MSc in Geochemistry from the University of Wisconsin-Madison (2010). She worked as an analytical chemist for the State of Wisconsin for 7 years before coming to UBC. Kate is currently in her fourth year of a PhD program in UBC’s Earth, Ocean and Atmospheric Sciences Dept. Her research interests fall at the intersection of urban geochemistry, environmental health, and public health. Kate explores the biogeochemical cycling of various metals within the environment with questions like Where do they come from? How are they transported? Where do they end up? She has a particular interest in the effects that built/engineered environments have on the natural world. Kate will be presenting some key results and applications from her doctoral work exploring the use of honey as a biomonitor for metal distribution in urban environments.


Fountains from hell: Towards a new understanding of explosive eruption columns

My name is Johan Gilchrist and I’m a PhD candidate at UBC studying geophysics with a focus on explosive volcanic eruptions. When I left New Jersey to begin my undergraduate studies at UBC, I did not know where this journey would take me, much less which major would position me best to help society. I was falling in love with the Cascade mountains of western North America and constantly wondering how they formed. I asked myself “If you love the mountains so much, why don’t you just study them?” So what have I learned about the Cascade mountains since? Volcanism built the Cascades that form the backdrop of Vancouver and when volcanoes explode violently, like the 1980 eruption of Mt. St. Helens, they inject hot mixtures of rocks, ash and gas tens of kilometers into the atmosphere to form an eruption column. Eruption columns are notorious for collapsing to Earth’s surface and destroying everything within a 10-100 km radius around the volcano, including the city of Pompeii, Italy during the AD 79 eruption of Mt. Vesuvius. Curiously, eruption columns tend to collapse periodically during an eruption, which raises a question- what drives the periodicity of eruption column collapse? By conducting laboratory experiments to simulate eruption columns, I’ve learned that the same physics governing the bobbing of water fountains on UBC campus also govern the periodic collapse of explosive eruption columns. Armed with this knowledge, I have created a new framework for classifying volcanic eruptions. This new eruption classification will help volcanologists protect settlements around volcanoes, direct air traffic away from ash clouds, understand how eruptions influence Earth’s climate, and determine the risk of a potential mass extinction event following a super eruption.