| INTRODUCTION Why study glaciers in the North Cascades of Washington? Glaciers are one of the world’s best climate monitors and are a critical water resource to many populated glaciated regions. This is particularly true in the North Cascades where 725 glaciers yield 200 billion gallons of runoff each summer and where the glaciers have lost 30 % of their area in the last century. Just as important is the magnificent wilderness that is the North Cascades and the biology that inhabits them This web page documents the principal findings of the North Cascade Glacier Climate Project (NCGCP) which monitors more glaciers than any other program in North America. NCGCP was founded in 1983 to identify the response of North Cascade glaciers to 
regional climate change, particularly changes in mass balance, glacier
runoff and terminus behavior. The North Cascades, Washington mountains
are host to approximately 725 glaciers. Summary Findings Between 1984 and 2005, NCGCP observed the terminus behavior of 47 glaciers all are currently retreating. Five of the glaciers have melted away completely. The rate of retreat increased in 1992 and again in 2001.
Annual mass balance surveys on nine glaciers in the North Cascades
indicate that North Cascade glaciers have lost an average of 0.5 m of thickness each year
from 1984-2005. This 11-12 m of
glacier thickness lost is approximately 20-40 % of the entire volume of
North Cascade glaciers, gone in twenty one years. The trend of
consistent negative balances and glacier thinning of the
1985-1995 period, has been replaced by wild fluctuations from
years of near record accumulation 1997 and 1999 to years of record
melt 1998 and 2001, and early season high snowfall for 2002, and
exceptionally negative balances in 2003-2005. North Cascade glaciers are an important summer water supply, more during dry summers and in heavily glaciated basins such as Baker Lake. Glaciers provide 230 billion gallons each summer. Key changes have been.
Most North Cascades glaciers are in a state of disequilibrium with the current climate meaning they cannot retreat to a point where equilibrium can be reestablished. These glaciers will melt away if the current climate continues. There
have been several interesting, if moderate, discoveries made during
the course of this study. Taxa
were dominated by ice worms, an oligochaete surprising in itself, and
by several new species of Collembola, including Isotoma (Myopia)
sp., Isotoma (Desoria) sp., and Agrenia sp.
The Agrenia sp. is particularly interesting because it occurred
only on the northernmost glaciers, in the Mt. Baker cluster, while the
only previously identified species of this genus occur in Arctic
environments. The Myopia sp. is near M. alaskana, previously
reported from glacier and non-glacier habitats in Alaska.
These distributions could support a model of distribution based
on historic contacts, with the northernmost being the most recent
arrivals to this area; or their extinction to the south could be a
result of previous stochastically-induced extinctions.
Phylogenetic study is required to solve this question. We observe The terminus behavior of 38 North Cascade glaciers during the last century to illustrate three different types of glacier response to climate change: 1) Retreat from the Little Ice Age (LIA) to approximately 1950 followed by a period of advance from 1950-1976, and then retreat since 1976. 2) Rapid retreat from the LIA to approximately 1950, slow retreat or equilibrium from 1950-1976, and moderate to rapid retreat since 1976. 3) Continuous retreat from the LIA to the present. These types reflect different physical characteristics. The initial response times (Ts) of North Cascade glaciers to both a positive and negative mass balance changes resulting from climate change have been observed on 21 glaciers to be 4-16 years. Climate Changes
|