Barclay, D.J., 1998, Tree ring and glacial records of Holocene climate change, northern Gulf of Alaska region: Buffalo, New York, State University of New York, Ph.D. dissertation, 232 p., illust., photos.
Tree-ring cross-dates of glacially overrun trees at eight sites around western Prince William Sound show ice margins advanced in the early (late 12th through 13th centuries AD) and middle (17th to early 18th centuries) Little Ice Age. Tree-ring dates of 22 moraines at 13 glaciers in the same region indicate an early period of moraine stabilization in the early 18th century. This overlaps with the second period of glaciers overrunning trees and marks culmination of this middle Little Ice Age advance. Moraine stabilization on nine of the study forefields in the latter 19th century delineates a third interval of Little Ice Age glacial expansion. These intervals of land-terminating glacier advance are synchronous with other tree-ring dated glacial histories from around the northern Gulf of Alaska, suggesting common climatic forcing across this region. Ring-widths in a 1,119-year-long tree-ring-width chronology developed from subfossil and living trees on glacial forefields around western Prince William Sound are primarily controlled by May through July temperatures of the growth year. Multi-decadal length warm periods in western Prince William Sound during the past 750 years were centered on 1300, 1440, 1730 and 1950 AD. Major cool periods were centered on 1400, 1660 and 1870 AD. Surficial mapping and 52 radiocarbon ages enable reconstruction of the Holocene glacial history of Yakutat Bay and Russell Fiord. Following an early to middle Holocene non-glacial interval, Hubbard Glacier began an advance at ~5600 cal. BP that culminated between ~4300 and 3474 cal. BP. Retreat by ~3200 cal. BP preceded readvance to Holocene maxima in Yakutat Bay and Russell Fiord at ~725 cal. BP (1225 cal. AD). The Hubbard ice margin in Yakutat Bay retreated by 1245 cal. AD, and was behind its modern position by 1791 AD. Ice from the Brabazon Range kept the Russell Fiord glacier lobe at its maximum until retreat during the late 18th and 19th centuries AD. The extent and timing of specific fluctuations of Hubbard Glacier are largely controlled by fjord geometry and glacial dynamics. Climatic warming may have triggered calving retreat.
Theses and Dissertations