Abstract: Luminescence measurements provide a chronology of a mineral grain’s exposure to heat and sunlight on timescales of 10 – 10^5 yr. In this talk, I will present three case studies where luminescence signals are used to understand geologic hazards. In the first study, I use luminescence signals from rapidly cooling bedrock to quantify differences in tectonic exhumation along the San Andreas fault in Southern California. This approach can identify which fault strands have been active in the Late Quaternary. In the second study, I estimate the ages of hydrothermal explosions in Yellowstone National Park. Whether these explosions are associated with periods of regional deglaciation informs the current hazard posed to park visitors. In the final study, I estimate how long subglacial bedrock has been covered by ice in the West Antarctic Ice Sheet. The history of ice sheet thinning and recovery in this region has implications for future sea level rise. 

Speaker bio: Nathan is a Quaternary geochronologist interested in tectonic geomorphology, paleoclimate, sediment transport, and geohazards. His work usually integrates field work, luminescence dating and numerical modeling.

Speaker website: https://nathandbrown.wixsite.com/home