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Hubbard Glacier, : Growing and Advancing in Spite of Global and the 1986 and 2002 Russell Outburst

Introduction 140o 139o , the largest calving glacier on the North American Continent (25 percent ALASKA MAP larger than Rhode ), advanced across the AREA entrance to 35-mile-long Russell Fiord (fi g.1) H U B B during June 2002, temporarily turning it into a lake. Hubbard Glacier has been advancing A R for more than 100 years and has twice closed D the entrance to Russell Fiord during the last MT LOGAN 60o 16 years by squeezing and pushing submarine 30' glacial across the mouth of the fi ord (fi gs. 2 and 3). fl owing into the cutoff Lowell Glacier fi ord from and glacier melt G L causes the level of Russell Lake to rise. How- A C I E ever both the 1986 and 2002 failed (fi g. 4) A TES before the lake altitude rose enough for water to d Glacier TA war C A N A D spill over a low pass at the far end of the fi ord Se V R and enter the Situk drainage, a world- UNITED S alerie Glacier class sport and commercial fi shery near Yakutat, Haenke Gl

Alaska. Turner Gl HYDROLOGIC BASIN 60o Osier Is BOUNDARIES Calving Glaciers are Unresponsive Haenke Is Variegated Gl to Climate Malaspina Russell Glacier Hubbard Glacier is defying the global para- hantment

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digm of or mountain glacier shrinkage ior Malaspina L F A I R and retreat in response to global climate warm- d ing. Hubbard Glacier is the largest of eight W E A calving glaciers in Alaska that are currently T H E R F A U L G Y A K U T A T B A Y increasing in total mass and advancing. All L A 1 C 1 IA 3 of these glaciers calve into the , are at the L 0 T AD ER +1 G U L F OM F 6 T heads of long fi ords, have undergone retreats IN 0 A tuk L P Yakutat Si Cr OS ld during the last 1,000 years, calve over relatively ITIO O 59o N Situk River shallow submarine , and have unusu- 30' A L Airport ally small areas compared to their A S K accumulation areas. A

Ablation: All processes by which and 0 10 20 MILES are lost from a glacier. 0 10 20 30 KILOMETERS Accumulation: All processes by which snow and ice are added to a glacier. Figure 1. Hubbard Glacier and Russell Fiord study area.

U.S. Department of the Interior USGS Fact Sheet 001—03 U.S. Geological Survey January 2003 Figure 3. Ice and blocking the entrance to Russell Fiord, July 7, 2002. Photo by U.S. Service.

Figure 2. Submarine glacial sediments emerging from the sea May 20, 2002. Photo by Bill Lucey, U.S. Forest Service.

For example, Hubbard Glacier retreated about 38 miles Figure 4. Outburst fl ood on August 14, 2002, about 9 hours after Russell Lake began to lose volume. Photo by Al Grillo, Associated Press between 1130 A.D. and late in the 19th century (fi g. 1). (published with permission). The fi ord bottom lies 1,300 feet below under the glacier, shallows to a depth of 200-250 feet at the glacier calving terminus, and then deepens again to as The 1986 and 2002 Formation and Growth of much as 750 feet below sea level down Disenchant- Russell Lake ment Bay. The accumulation area of Hubbard Glacier is 95 percent of the entire glacier area and, like the other The 1986 closure occurred near the fi rst of June; the 2002 growing calving glaciers, is far from being in equilib- closure was gradual and was complete about June 16. The rium with climate. newly closed Russell Lake basin fi lled at the average rate The large calving glaciers that are currently advanc- of 0.7 feet per day in both 1986 and 2002 (fi g. 5). No water ing have been discordant with climate-driven glacier was visibly leaking through or over the dam during the 1986 changes for a very long time. The glaciers that are closure. However, relatively small amounts of lake water currently growing and advancing in the face of global overfl owed the 2002 moraine dam during most of the period warming were retreating throughout the Little of closure (fi g. 3). This observation suggests that the dam- (AD1350 or 1450 to AD1900) when most glaciers ming moraine was being squeezed higher above sea level were growing.

2 140 Estimated level at which Russell Lake will overflow into the Situk River 2.0 130 The 1986 and 2002 Russell 120 110 Lake Outburst Floods 100 1.5 90 The 1986 dam failed catastrophi- 80 cally during the night of October 8 70 1.0 60 (fi g. 7) releasing a fl ood that rapidly 50 1986 accelerated to a maximum of about

40 IN CUBIC MILES 30 0.5 4,000,000 ft3/s about 6 hours after the

IN FEET ABOVE SEA LEVEL 20 2002 10 initial failure (fi g. 7). The 2002 dam LAKE VOLUME ABOVE SEA LEVEL, RUSSELL LAKE SURFACE ALTITUDE, 0 0.0 began to fail when the lake surface June 1 July 1 August 1 September 1 October 1 Figure 5. Filling and emptying of Russell Lake during 1986 and 2002 . altitude reached about 49 feet above sea level (fi g. 5). A rainstorm caused a rapid lake rise that increased the 100 1986 Russell Lake 5 volume of water fl owing over the 90 2002 Russell Lake 80 2002 Yakutat moraine dam, which also increased the 4 70 rate of of the dam. The growth 60 of the moraine dam by glacier fl ow 3 did not keep pace with erosion and the 50 dam progressively failed (fi g. 7). Dam 40 2 failure released a fl ood that reached a 30 maximum discharge of 1,850, 000 ft3/s

OF CUBIC FEET PER SECOND 20 1

PER DAY BASIN AREA about 21 hours later (about midnight NET LAKE INFLOW, IN THOUSANDS 10 OR NET LAKE INFLOW, IN INCHES on August 14). These two fl oods 0 0 YAKUTAT PRECIPITATION, IN INCHES June 1 July 1 August 1 September 1 October 1 are the largest recorded glacial-lake Figure 6. Russell Lake fi lling rates and 2002 precipitation at Yakutat, outburst fl ood events in historical time Alaska. ( 1).

4,000 Table 1. Peak discharges of largest known historic glacial 3,500 lake outbursts Peak 3,000 Location Date discharge (ft3/s) 2,500 August 13-14, 2002 October 7-8, 1986 1. Russell Lake, Alaska 1986 3,970,000 2,000 Outburst Outburst 2. Russell Lake, Alaska 2002 1,850,000 1,500 3. Grimsvatn, 1934 1,770,000 4. Chong Kumdan, India 1939 800,000 1,000 5. Berg Lake, Alaska 1983 600,000 500 6. Chakachamna Lake, Alaska 1971 470,000

OF CUBIC FEET PER SECOND 7. Lake George, Alaska 1958 360,000 0 NET LAKE OUTFLOW, IN THOUSANDS -500 -3 0 3 6 9 12 15 18 21 24 27 30 33 Peak discharge of Mississippi R. 1937 1,980,000 at Memphis, Tennessee TIME SINCE START OF OUTBURST, IN HOURS Figure 7. Russell Lake 1986 and 2002 outburst fl oods.

throughout the 2002 closure period. The volume of water fl ow- The maximum recorded discharge of ing into the lake can be calculated from the rates of lake level the Mississippi River upstream from the rise (fi g. 6). During the 1986 closure, the average infl ow rate fl ood-control structures on the lower was 15,000 cubic feet of water per second (ft3/s). The maximum river is about 7 percent larger than the rate of infl ow was about 44,000 ft3/s, which occurred on maximum discharge during the 2002 August 13 in response to a 2-week-long rainstorm in the area. outburst fl ood from Russell Lake and During the 2002 closure, the average net infl ow rate was about about one-half the size of the 1986 out- 18,700 ft3/s and the maximum rate was about 92,000 ft3/s, burst fl ood from Russell Lake. which occurred on August 12, also in response to a rainstorm (fi g. 6).

3 Additional Reading Long-Term Advance and Repeat Closure of Mayo, L.R., 1989, Advance of Hubbard Glacier and 1986 Russell Fiord Expected outburst of Russell Fiord, Alaska, U.S.A.: Annals of , v. 13, p. 189-194. Hubbard Glacier has advanced at a rate of about 80 feet per year since 1895 (fi g. 8). Although the timing is uncer- Seitz, H.R., Thomas, D.S., and Tomlinson, B., 1986, The stor- tain, the prospect of the glacier continuing to advance and age and release of water from a large glacier-dammed lake: again blocking the entrance to Russell Fiord is much more Russell Lake near Yakutat, Alaska, 1986: U.S. Geological certain. Survey Open-File Report 86–545, 10 p.

0 1 2 3 MILES Trabant, D.C., Krimmel, R.M., and Post, A., 1991, A Flow preliminary forecast of the advance of Hubbard Glacier 01 2 3 4 KILOMETERS and its infl uence on Russell Fiord, Alaska: U.S. Geological Survey Water- Investigations Report 90–4172, 34 p. 1948 1895 Flow N 2001 1988 Cooperating Agencies: Hubbard Glacier U.S. Forest Service 648 Mission Street Federal Building

Russell Ketchikan, AK 99901-6591 hantment F Bay ior 907-225-3101 d http://www.fs.fed.us/r10/tongass/ Disenc National Park Service Wrangell-St. Elias National Park and Preserve Figure 8. Terminus positions of Hubbard Glacier in 1895, 1948, 107 Richardson Highway 1988, and 2001 showing advances during the last 106 years. P.O. Box 439 Copper Center, AK 99573 907-822-5234 http://www.nps.gov/wrst/

For more information, please contact:

U.S. Geological Survey 4230 University Drive, Suite 201 Anchorage, AK 99508-4664 Hubbard Glacier 907-786-7100 http://ak.water.usgs.gov Russell Lak e Ice moraine dam site U.S. Geological Survey Glaciology Disenchantment Bay P.O. Box 75-7300 930 Koyukuk Drive Fairbanks, AK 99775-7300 907-474-1934 Hubbard Glacier, June 13, 1986. Photo by Rod March, U.S. Geo- http://ak.water.usgs.gov/glaciology/ logical Survey.

—D.C. Trabant, R.S. March, and D.S. Thomas U.S. Department of the Interior U.S. Geological Survey Fact Sheet 001—03 January 2003

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