Dendroclimatology of
the Columbia Bay Region,
Prince William Sound,
Alaska*
*This
material is based upon work supported by the National Science
Foundation under Grant No. 9910805. Any opinions, findings, and
conclusions or recommendations expressed in this material are
those of the author and do not necessarily reflect the views of
the National Science Foundation.
Aaron Shear
The College of Wooster
The Columbia Glacier is a 60km-long, iceberg-calving, piedmont
glacier located in Prince William Sound, Alaska. The retreat of
this great tidewater glacier from its Little Ice Age maximum began
in 1982. Partly buried mountain hemlock forests along a section
of the 15km fjord were exposed due to this retreat.

During the past summer (2000), four other scientists and I had
the opportunity to travel to this region of southern Alaska to
take part in dendrochronologic / dendroclimatic research concerning
the Columbia Glacier. The project was funded by a National Science
Foundation grant to Parker E. Calkin of the Universirty of Colorado
at Boulder, Greg Wiles of The College of Wooster and David Barclay
at SUNY-Cortland. The primary objective of this research was to
help develop a continuous tree-ring chronology from living and
subfossil wood around Prince William Sound that would span the
past 2000-years. The 2000 year chronology will be developed by
linking and extending existing tree-ring records with new collections
of subfossil and living wood. We took samples from subfossil logs
either in the form of cores or disks, while living trees were
sampled using non-destructive increment borers.

This new record will be used to: reconstruct the Holocene history
of the Columbia Glacier, provide calendar-dates to early Medieval
(AD 600) glacial advances around the northern Gulf of Alaska,
and finally to asssess climate change in the North Pacific region
over the past two millennia through calibration with meteorological
records and dendroclimatic reconstruction. My area of emphasis
on the project will be in the area of dendroclimatology and examining
what the tree-ring record tells us about climate.
By comparing the collected tree-ring data with meteorological
record I will be able to identify the most important climatic
variables that influenced the growth of the mountain hemlocks,
and that ultimately lead to the advance or retreat of the Columbia
Glacier throughout the past several hundred years. Meteorological
records stretching back into the early to mid 1900s can be acquired
from stations in Seward, Valdez, and Cordova. Longer records will
be used for comparison with regional climate will be taken from
stations at Kodiak and Sitka.
Such reconstruction of past climate is accomplished by taking
several steps. The first of which is to compare the modern meteorological
records with the widths of the collected tree rings that were
produced during the same period of time. The second step is to
establish a statistical relationship between the meteorological
record and tree ring record. Finally by substituting the widths
of the dated rings (using them as a proxy). these estimates of
climate from tree rings can substitute for meteorological reocords
and thus provide valuable information concerning climate for periods
and areas where no meteorological data exists.
http://www.wooster.edu/geology/hdgd/Aaron.html
http://www.wooster.edu/geology/Orthids.html
http://www.ldeo.columbia.edu/trl/index.html
http://www.sonic.net/bristlecone/dendro.html
http://www.geog.psu.edu/tree/research.html
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http://academic.emporia.edu/aberjame/geomorph/climate/climate.htm
http://www.treeringsociety.org/TRS_links.html
http://www2.sunysuffolk.edu/mandias/honors/student/paleoclimatology/