Glacier in northern
Southeast Alaska, near
Yakutat. A relatively large
tidewater glacier, the Hubbard Glacier drew much attention in 1986 and again in 2002 when it has temporarily blocked off the nearby
Russel Fjord during periods of major surging activity.
The terminis of the Hubbard Glacier is located directly across from the North end of the Yakutat Penninsula, a spit of land bounded on the North by Disenchantment Bay (a large sound-like body of water opening directly into the Gulf of Alaska), and on the South by Russel Fjord (a narrow inlet that begins at the eastern end of Disenchantment bay and protrudes about 65 miles in the southwestern direction). The glacier originates in the St. Elias Mountains to the North and West of the Yakutat Penninsula.
Since about 1900, the Hubbard Glacier has been steadily advancing. While this occurred gradually for along time, the pace of the glacier's advancement greatly accelerated in about 1971. By the early 1980s, the Hubbard had advanced well into Disenchantment Bay, leaving only a narrow channel between the eastern end of the bay and the beginning of Russel Fjord.
As a result, when the glacier first underwent a major surge in 1986 (advancing about 30 metres during the first few months of that year), the terminis reached the tip of the Yakutat Penninsula, completely blocking off the Russel Fjord and trapping sealife behind this "ice dam". This situation drew a great deal of concern, not only because of the threat to the trapped wildlife; but because of the danger that, should the water level rise substantially in the newly created "Russel Lake" (the blocked-off fjord), it could cause flooding in the Yakutat area.
By October of 1986, the ice dam had begun to leak; and shortly thereafter ruptured fully, clearing the channel between Russel Fjord and Disenchantment Bay. This rupture occurred largely because the water level in "Russel Lake" had risen 30 metres since the fjord had been blocked off in May of that year, placing an immense amount of pressure on the ice dam.
Update: After the breaking of the ice dam, the Hubbard resumed advancing, but at a slower rate. Beginning in 2002, however, the Hubbard underwent a series of surges lead to the formation of a new ice dam in June, 2002. Between mid-June and mid-August of that year, the water level in
Russel Lake rose more than 50 feet, once again creating concern about flooding that could affect fishing habitat (commercial
charter fishing is a large component of
Yakutat's economy). In August 2002, however, the glacier formed a leak and water began gushing out of
Russel Lake (or
Russel Fjord, as the case may once again be).