Documenting Twentieth Century Glacier Change with Repeat Photography in the Sierra Nevada, California
HASSAN J BASAGIC; ANDREW G. FOUNTAIN
Department of Geography, Portland State University, Portland, Oregon, 97207
Introduction
Repeat Photography
Alpine glaciers are important indicators of climate trends within a region and play a
significant role in the hydrology of alpine ecosystems. The Sierra Nevada of California
contains approximately 497 alpine glaciers and perennial ice features (Raub, 1980).
These glaciers provide an opportunity to determine regional responses to warming
global temperatures over the past century. Historical photos of glaciers taken by early
explorers, land surveyors, and park rangers in the late 19th century and early 20th
century are valuable records of past conditions. Repeat photography of glaciers is a
useful way to determine how these Sierra Nevada glaciers and perennial ice features
have changed through time. During the summer of 2003 and 2004, over 52 repeat
images were collected from ten glaciers located throughout the Sierra Nevada.
We gathered historical photos from the USGS Earth Science Photographic Archive (http://libraryphoto.er.usgs.gov/)
and re-photographed following methods outlined by Harrison (1960) and Klett et al. (1984). The data
serve as a visual comparison of change through time. Below are the results from four of the ten
locations.
Dana Glacier
Quantifying Glacier Change
Change in glacier area was calculated for Lyell Glacier in Yosemite National Park for
the three time periods of 1883, 1944, 2003. Early photographs and a map by I.C.
Russell indicate that the Lyell glacier extent was near or at the Matthes, or Little Ice
Age maximum (Russell, 1885). The 1944 extent was delineated from aerial and
ground based photographs. The 2003 extent was collected in the field with GPS.
Kilometers
0
120°0'0"W
2.5
5
119°0'0"W
1883 map of Lyell Glacier (Russell,
1885)
1883
I.C. Russell
1944 Army aerial photograph
September 5, 2004 H. Basagic
Lyell Glacier
Mapping terminus with GPS
350 0
36
00
36 00
70
0
38°0'0"N
38°0'0"N
3
36 00
370 0
Surface Area of Lyell Glacier
1883 - 2003
0.8
0.7
38
5
Legend
1883
I.C. Russell
$
H. Basagic
August 15, 2003
Glaciers and perennial ice
00
3 9 00
0
39 0
+
MOUN
N T LL Y
YE
EL L
3 9 9 88 m
+
PE A
AK
3 9 22 77 m
m
1883
High : 4412
37°0'0"N
Low : 672
20
$
0.3
0.2
220
1900
1950
2000
Year
440
West Lobe
East Lobe
37°0'0"N
Conclusion
40
August 7, 1903
G.K. Gilbert
September 5, 2004
H. Basagic
Darwin Glacier
120°0'0"W
0.4
0.0
1850
2003
0
1:800,000
10
0.5
Met ers
Kilometers
0
0.6
0.1
1944
Moraines and rock glaciers
Elevation (m)
Surface Area (km 2)
3 700
0
2.5
0
38
38 00
Kilometers
0
Comparisons of the repeat photography reveal that all ten of the glaciers have
experienced a reduction in ice volume and surface extent over the past century.
Repeat photography is a valuable tool in determining change through time, especially
when combined with aerial photos and field measurements. The case example at
Lyell Glacier indicate the surface area of the west lobe has been reduced by 30%
since 1883, and the smaller east lobe has been reduced by 70%. These results
suggest that topographic controls strongly influence individual glacier response to
regional and global climate change.
119°0'0"W
References
Glacier regions of the Western United States
Sierra Nevada Glacier Inventory
We performed an inventory of all Sierra Nevada glaciers, perennial ice, and
snowfields to understand the distribution and quantity of these features. The GIS
database is based on USGS 7.5 minute topographic quadrangle maps (1:24,000
scale). The USGS created these topographic maps from aerial photos taken between
1975 and 1984. A total of 1795 ice and snow features were found along with 454
moraines and rock glaciers.
Harrison, A.E., 1960. Exploring Glaciers-with a Camera. Sierra Club Books, San Francisco, CA, 71 pp.
August 14, 1908
G.K. Gilbert
August 14, 2004
Klett, M., Manchester, E., Verburg, J., Bushaw, G. and Dingus, R., 1984. Second View: The Rephotographic
Survey Project. Essay by Paul Berger. University of New Mexico Press, Albuquerque.
H. Basagic
Raub, W.B., Post, A., Brown, C.S. and Meier, M.F., 1980. Perennial ice masses of the Sierra Nevada, California,
World glacier inventory. IASH-AISH Publication 126: 33-34.
Goddard Glacier
Russell, I.C., 1885. Existing Glaciers of the United States. 5th Annual Report of the U.S. Geologic Survey
U.S. Geological Survey, Earth Science Photographic Archive.Online at http://libraryphoto.er.usgs.gov
Acknowledgements
Special thanks to Danny Boiano, Annie Esperanza, Pat Lineback, and DNR at Sequoia & Kings Canyon National
Parks; Nate Stephenson, BRD, USGS; and Hal Pranger, Geologic Resources Division, NPS.
August 13, 1908
G.K. Gilbert
August 16, 2004
H. Basagic