2002 Russell Fiord Closure and Russell Lake Outburst

Photo June 14, 2002

Photo June 20, 2002

Photo June 23, 2002

Photo June 28, 2002 by National Park Service.

Photo July 3, 2002 by National Park Service.

Photo July 16, 2002 by US Forest Service.

Photo July 21, 2002 by US Forest Service.

Photo August 10, 2002 by National Park Service.

Photo August 14, 2002 by National Park Service.

Photo August 15, 2002 by National Park Service.

Photo May 20, 2002

Had the blockage held, Russell Lake would have eventually overflowed into the Situk River when its level reached about 40 meters (130 feet) above sea level.

In late May or early June, 2002, Hubbard Glacier pushed a moraine plug across the seaward entrance to Russell Fiord and began to restrict the tidal exchange between Disenchantment Bay and Russell Fiord. By early June, as the moraine continued to grow, the tidal exchange was blocked. From then on, a delicate balancing act was played out between the slow advance and growth of the moraine dam from glacier movement and its erosion by water overflowing the dam. Early in the blockage, small amounts of water leaked from Russell Lake over the moraine dam into Disenchantment Bay. Despite this small leak, the dam held and lake level rose at an average rate of more than 0.24 meters per day (0.8 feet per day) because of the large amount of runoff and glacial melt in the basin. By late July, the dam completely sealed off the lake.

August 10 photographs showed that the water was again flowing over the dam. On August 11 and 12 heavy rains fell in the area (nearly 4 inches alone on Aug. 12). This may have tipped the balance in favor of the dam's erosion though other factors such as possible slow down of the glacier's movement or reduced growth of the moraine may also have played a role.

At about 3 a.m., Aug. 14, real-time USGS water gage data revealed that the water level in the Lake had peaked at about 18.6 meters (61 feet) above sea level and had begun to drop.

 The outflow increased throughout the day due to rapid erosion of the lake outlet channel. Water discharge peaked at about midnight on Aug. 14 with a one-hour average rate of 54,000 cubic meters per second (1.9 million cubic feet per second) at a lake level of 11 meters (36 feet), which meant a water-level drop of nearly 0.9 meter per hour (3 feet/hour). By 10 a.m. on Aug. 15, the lake level had dropped below the USGS water gage sensor level of 4.9 meters (16 feet) above sea level, with the discharge still at about 14,000 cubic meters per second (500,000 cubic feet per second). The lake level returned to its more normal sea level by early afternoon on Aug. 15, ending the outburst event about 36 hours after it started, and returning the lake to its former status as a fiord. The recent episode carved out a new 200 meter-wide (600 feet) entrance into Russell Fiord and the entire moraine dam is now gone. A total of 3.86 cubic kilometers of stored water (0.9 cubic miles) were discharged in the outburst event.

 A one-hour peak discharge of 54,000 cubic meters of water per second (1.9 million cubic feet per second) is the second largest measured glacial lake outburst worldwide in historical times, exceeded only by the 1986 outburst from Russell Lake, which was about 105,000 cubic meters per second (3.7 million cubic feet per second). In comparison, the August 14 peak discharge was about 30 percent greater than the peak historic flow on the Mississippi River at Baton Rouge, La.

Photographs made by the U.S. Geological Survey, the U.S. Forest Service, Yakutat Range District, and the U.S. National Park Service, Yakutat Ranger Station. Click on any photo for enlargement of the entire series (about 750 KB.