Holocene tephra stratigraphy, Cook Inlet region
Tephra layers preserved in lacustrine sediments near active volcanoes provide a valuable record of the long-term frequency and magnitude of ash-fall events. Lakes are important repositories for tephra because their sediments accumulate continuously and they include organic material for 14C dating. As part of a collaborative project with the Alaska Volcano Observatory, my students, colleagues, and I use sediment cores from lakes across the Cook Inlet region (Kenai Peninsula, upper Alaska Peninsula, and Anchorage area) to improve our understanding of ashfall hazards. The lakes are located downwind of the historically active volcanoes of the Aleutian Arc. We use magnetic susceptibility and petrographic analysis to detect tephras, and 14C dating of organic material to determine their ages and to correlate tephras among the lakes.
