Tree-ring dates on two pre-Little Ice Age advances in Glacier Bay National Park and Preserve, Alaska, USA

Researchers have identified two significant glacial advances in Glacier Bay National Park and Preserve, Alaska, predating the Little Ice Age. Using tree-ring chronologies from Geikie Inlet, they determined one advance occurred around AD 850, while another took place between 3400 and 3000 cal yr BP. The study cross-dated one chronology with living trees in Prince William Sound, providing calendar dates, whereas the second relied on radiocarbon dating due to its floating status. These findings align with glacial expansion patterns observed in other Alaskan and British Columbian tidewater glaciers, offering a more precise timeline for past glacial activity in the region.

Wiles, G. C., Lawson, D. E., Lyon, E., Wiesenberg, N., & D’Arrigo, R. D. (2011). Tree-ring dates on two pre-Little Ice Age advances in Glacier Bay National Park and Preserve, Alaska, USA. Quaternary Research, 76(2), 190–195. https://doi.org/10.1016/j.yqres.2011.05.005