Society of Woman Geographers

From recent and ongoing research of Southern California's paleoclimate, a picture of the last glacial period is emerging that involves dynamic, high-amplitude changes between warm and cold states that have no modern analogue. Lake deposits from the once-glaciated San Bernardino Mountains span 125,000 years, and multi-proxy analyses were conducted on the biologic, physical, and chemical markers in these deposits. Large shifts in organic deposition and lake productivity over time suggest that changes in incoming summer solar radiation was a key driver for lake primary productivity in subalpine watersheds. Smaller-scale increases in organic deposition from 60,000 - 20,000 years BP match North Atlantic warming events, suggesting that as Arctic underwent sudden change, so did Southern California. Pollen and charcoal accumulation at the sites show times of forest expansion and contracting, and the changing role of wildfire in California's mountains over long timescales. Katherine's current work seeks to use plant macrofossils and pollen from the La Brea Tar Pits collection at 50,000 - 30,000 years BP to test if entrapment events correlated with known warming events, and model the net primary productivity available to the region's ice age animal community. Use this link to register: https://zoom.us/webinar/register/WN_dDibext1Tby2vHKUOE4MKQ Katherine earned her Ph.D. in Geography from UCLA in December 2016, and conducts research, education and outreach across the fields of geography, earth science, and ecology. Her research aims to understand the processes that shaped landscapes in the past, and how this can inform future scenarios of change. She has used lake cores to develop long-term histories that span glacial conditions throughout North America, including Alberta, the Great Lakes region, and the mountains of Southern California. In addition to research, Katherine has worked as a high school science teacher, and a naturalist and park aide in California's state and national parks. Currently, she is a postdoctoral researcher at the Climate Change Institute, University of Maine as part of the La Brea Food Webs project.