HR: 0800h
AN: C41A-0043    [Abstracts]
TI: Hubbard Glacier Update: Another Closure of Russell Fjord in the Making?
AU: * Motyka, R J
EM: jfrjm@uas.alaska.edu
AF: Geophysical Institute University of Alaska, 903 Koyukuk Dr., Fairbanks, AK 99775, United States
AU: Lawson, D
EM: Daniel.E.Lawson@erdc.usace.army.mil
AF: CRREL, 72 Lyme Rd, Hanover, NH 03755, United States
AU: Finnegan, D
EM: David.Finnegan@erdc.usace.army.mil
AF: CRREL, 72 Lyme Rd, Hanover, NH 03755, United States
AU: Kalli, G
EM: George.A.Kalli@poa02.usace.army.mil
AF: Army Corp of Engineers, Alaska District, Anchorage, AK 99777, United States
AU: Lingle, C
EM: craig.lingle@gi.alaska.edu
AF: Geophysical Institute University of Alaska, 903 Koyukuk Dr., Fairbanks, AK 99775, United States
AB: Hubbard Glacier is located near the community of Yakutat in southeastern Alaska. It is the largest non-polar temperate tidewater glacier in the world and has been advancing since 1890 AD, currently at a rate of 35 m a-1. Hubbard Glacier has twice closed off Russell Fjord creating enormous glacier dam lakes, once in 1986 and again 2002. Both dams failed catastrophically producing two of the largest outburst floods in historic times. Past closures were facilitated by the terminus pushing glaciomarine sediments above tidewater near Gilbert Point (where past dams have closed Russell Fjord), thus limiting calving losses and allowing the glacier to advance rapidly across the 200-300 m gap. A new push moraine is currently emerging in the same location as past dam forming events, causing concern that a new closure may be eminent, perhaps as early as this winter (2007-08). Such an occurrence is of concern to local inhabitants because sustained damming of Russell Fjord will cause the lake to overflow into the Situk River, dramatically changing the landscape, creating floods, destroying fish habitats, and threatening structures. In this poster we will present results of October 2007 field measurements and remote sensing investigations on the evolution of the glacier push moraine and provide updates on the potential for another closure of Russell Fjord.
DE: 0720 Glaciers
DE: 0758 Remote sensing
DE: 1808 Dams
DE: 1817 Extreme events
DE: 1824 Geomorphology: general (1625)
SC: Cryosphere [C]
MN: 2007 Fall Meeting