Holocene Glacial History of Climate Change in the Puget Sound Basin
May 20, 2026 | 12:00 – 1:00 pm
This presentation reviews 40 years of research using glaciers and glacial deposits to understand the climate history of the North Cascades. It begins with a summary of the Holocene record of glacial activity based on radiocarbon ages of forests buried by glacial till around Mount Baker. The second part of the talk will focus on the punctuated retreat of glaciers in the past century. A stunning photographic record of these changes will be presented along with 50 years of glacial mass balance data collected at nine glaciers surrounding Puget Sound.
Jon L. Riedel, Ph.D., is a geologist with more than 40 years of experience studying the glacial and fluvial history of the Skagit Valley. He holds degrees from the University of Wisconsin and Simon Fraser University, and has authored over a dozen peer-reviewed publications. During his career with the National Park Service at North Cascades National Park, Jon led major efforts to address erosion and river management challenges, including the development of the Stehekin River Management Plan and long-term erosion control strategies for Lake Chelan and the Skagit reservoirs. He also founded a glacier monitoring program that expanded across multiple national parks. Jon continues his work as a licensed consulting geologist through his consulting firm, Skagit Quaternary, where he is leading regional geologic mapping and groundwater investigations, and remains actively engaged in the scientific community through research, board service, and regional environmental leadership.