Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Michael A. O'Neal, Dept. of Geography. Includes bibliographical references.

Glaciers respond to local climate changes making them important indicators of regional climate change. The North Cascades region of Washington is the most glaciated region in the lower-48 states with approximately 25% of all glaciers and 40% of the total ice-covered area. While there are many on-going investigations of specific glaciers, little research has addressed the entire glacier cover of the region. A reference inventory of glaciers was derived from a comparison of two different inventories dating to about 1958. The different inventories agree within 93% of total number of glaciers and 94% of total ice-covered area. To quantify glacier change over the past century aerial photographs, topographic maps, and geologic maps were used. In ~1900 total area was about 533.89 ± 22.77 km2 and by 2009 the area was reduced by -56% ± 3% to 236.20 ± 12.60 km2. Most of that change occurred in the first half of the 20th century, between 1900 and 1958, -245.59 ± 25.97 km2 (-46% ± 5%) was lost, followed by a period of stability/growth in mid-century (-1% ± 3% from 1958-1990) then decline since the 1990s (-9% ± 3% from 1990-2009). The century-scale loss is associated with increasing regional temperatures warming in winter and summer; precipitation shows no trend. On a decadal time scale winter precipitation and winter and summer temperatures are important factors correlated with area loss. Topographically, smaller glaciers at lower elevations with steeper slopes and higher mean insolation exhibited greater loss than higher, gentler more shaded glaciers.

Glaciers in the North Cascades store winter snowfall as ice and release it in late summer as melt, providing an important regional source of water and hydroelectric energy. The future of glaciers in the North Cascades, Washington, were evaluated using a regional glaciation model driven by the Community Climate System Model 4 global climate model. The climate model was coupled with three Representative Concentration Pathways (RCPs), 2.6, 4.5, and 8.5. These RCPs provide a business-as-usual scenario (RCP 8.5), which assumes society makes little to no efforts to reduce greenhouse gas emissions, a best-case scenario (RCP 2.6) with strong attempts to mitigate greenhouse gas emissions, and a moderate scenario (RCP 4.5). Spun up from 850 C.E., modeled glacier area for 1970 was 96-102% of observed. By 2100 the predicted area relative to the total observed area in 1900 was 42% for RCP 2.6, 16% for RCP 45, and 5% for RCP 8.5. By 2100 only glaciers on high peaks, such as Mt. Baker and Glacier Peak, will remain (145.98 km2, RCP 2.6; 70.49 km2, RCP 4.5; 16.82 km2, RCP 8.5) and entirely gone by 2200 in any of the three climate scenarios.

Thesis (Ph. D.)--University of Washington. / Bibliography: l. [144]-154.