LATE-HOLOCENE GLACIATION AND 20TH-CENTURY RETREAT, NORTHEASTERN BROOKS RANGE, ALASKA

Lichenometric dating of moraines deposited by eight glaciers in the no rtheastern Brooks Range suggests major glacial advances or stillstands at about 2600, 1000, 450, and 60 lichenometric (t) years BP. The latt er two advances of the early-middle and latest part of the 'Little Ice Age', respectively, formed prominent moraines at all glaciers studied . In response to overall twentieth-century warming, these glaciers hav e retreated at average rates of 2 to 19 m yr(-1) from the distinct rid ges formed in AD 1890. Glacier thinning at rates of 0.7 to 0.9 m yr(-1 ) accounts for over 90% of the ice loss.