Glacier Bay Basin, in southeastern Alaska, United States, encompasses the eponymous Glacier Bay and the surrounding mountains and glaciers. It was first proclaimed a U.S. National Monument on February 25, 1925, and later enlarged and re-designated as Glacier Bay National Park and Preserve on December 2, 1980, under the Alaska National Interest Lands Conservation Act, covering an area of 3,283,000 acres (1,329,000 hectares). In 1986, UNESCO declared an area of 57,000 acres (23,000 hectares) within the park a World Biosphere Reserve, making it the largest UNESCO-protected biosphere in the world. In 1992, UNESCO included the area as part of a much larger World Heritage Site, extending over an area of 24,300,000 acre (9,800,000 ha) which also includes Wrangell–St. Elias National Park and Preserve, as well as Kluane National Park and Reserve and Tatshenshini-Alsek Provincial Park, both in Canada. Part of Glacier Bay National Park is also designated a wilderness area covering 2,658,000 acres (1,076,000 hectares).
Current glaciers cover a combined area of , accounting for 27 percent of the park area. Until the early 1700s, the area was a single large glacier of solid ice. It has since retreated and evolved into the largest protected water area park in the world. Glacier Bay, on the Gulf of Alaska, was once part of the Grand Pacific Glacier, about thick and around in width. Over the last 200 years the glaciers have retreated, exposing of ocean, and in this process have divided into 20 other separate glaciers. In 1890, the name "Glacier Bay" was given to the bay by Captain Lester A. Beardslee of the U.S. Navy.
Glacier Bay has many scenic branches, inlets, lagoons, islands, and channels that hold prospects for scientific exploration and tourism. The area is popular as a cruise ship destination during the summer. However, there are restrictions imposed by the National Park Service on the number of vessels that can operate in a day: two cruise ships, three tour boats, six charter vessels, and 25 private vessels. The bay received an average of 443,975 recreational visitors annually from 2012 to 2021, with 89,768 visitors in 2021.
History
Geologists believe that Glacier Bay existed during a minimum of four glacial periods ending with the Little Ice Age, which has a 4,000-year-old record, as the latest period. All glaciers in the park today are said to be remnants from this glacial period.
The earliest recorded history of the Glacier Bay area starts with the 1741 Russian expedition led by Vitus Bering and Aleksei Chirikov. La Pérouse (after whom one of the glaciers in the bay was named subsequently) established contact with the local inhabitants, the Tlingit at Lutya Bay, in 1786, though traditionally the Tlingit lived in the area before the last glacial advance forced them out. This was followed by the Russians staking their claim to the region.
In 1794, Joseph Whidbey, master of the Discovery during George Vancouver's 1791–1795 expedition, reported that his exploration of this part of the coast was blocked by a wall of width and thick. Vancouver claimed the land for Britain in conflict with an earlier Russian claim, which was resolved by the Anglo-Russian Convention of 1825. The United States purchased Alaska from the Russians in 1867 with a claim under that treaty of owning all lands up to "the summit of the mountains situated parallel to the coast". The United States and Canada agreed that an arbitration board would draw the exact boundary. The arbitration award given in 1903 resolved the Alaska boundary dispute by drawing a line that linked the mountain peaks in this area. Because the agreement froze the exact boundary in 1903, further retreat of the glacier does not alter the boundary as the coast extends northward. As a result, the northern edge of Tarr Inlet is approaching the boundary.
With the discovery of gold in the area, the resulting gold rush brought miners to the area. In 1890, Willoughby Island in Glacier Bay was the scene of a meeting between the miners, which was followed by the establishment of the Berry mining district. In the 1890s, a salt mine was established at Bartlett Cove. Fox farms and a cannery were also established; the cannery was abandoned in 1935.
John Muir, the naturalist, conservationist and scientist, pioneered the focus of the world on the Glacier Bay phenomenon. During his research Muir witnessed the glaciers in action. He had noted that the ice had retreated almost all the way up. In his 1915 memoir Travels in Alaska, Muir reported that when he first visited the Bay in 1879, this wall was wide and retreated from the sea by . Today it has retreated to , as a remnant of the old wall of the glacier system, and has 16 major tidewater glaciers (10, 12 and 15 are also mentioned in some references).
In 1899, wealthy railroad magnate Edward Harriman arranged for a maritime expedition called the Harriman Alaska Expedition comprising an elite community of scientists, artists, photographers, and naturalists to explore and document the Alaskan coast. The expedition spent two months traveling from Seattle, along the coast of Alaska, to Siberia, and back again. In many ways, the expedition was an intersection of 19th-century and 20th-century science. The expedition claimed to have discovered some 600 species that were new to science, including 38 new fossil species. They charted the geographic distribution of many species. They discovered an unmapped fiord and named several glaciers. John Muir and his friend Harriman, both of whom were members of the expedition, were instrumental in governmental lobbying on National Park legislation. The Harriman expedition was instrumental in documenting the extent of the glacier's retreat in 1899.
Muir was seeking corroboration of the continental glaciation theories of Louis Agassiz, whose controversial Etudes sur les Glaciers was published in 1840. The year 1893 recorded the arrival of the first tourist ship at the entrance to the Bay, at Bartlett Cove, which over the years has become central to the tourist trade in the Glacier Bay. By 1916, the Grand Pacific Glacier was at the head of Tarr Inlet, about from Glacier Bay's mouth. This is the fastest documented glacial retreat ever. In 1925, Glacier Bay was declared a national monument.
For centuries, Glacier Bay has been the homeland of the Huna Tlingit native tribes of Alaska. Their oral traditions indicate being displaced by the last advance of the glacier. They continue to be part of the Bay residents and it is woven into the "tapestry of their lives".
Geography
Glacier Bay is subsumed within the larger about National Park and Preserve. The preserve, which is a spectacular ensemble of marine and terrestrial life, is delimited by: The Tongass National Forest borders on the east and north east; by the international boundary with Tatshenshini-Alsek Wilderness Provincial Park in British Columbia, Canada on the north; by the waters of Cross Sound and Icy Strait border on the south; and by the Pacific Ocean on the west. When President Calvin Coolidge declared the Glacial Bay to be a national monument, in 1925, the objective clearly stated was:
The Alaska National Interest Lands Conservation Act of 1980 changed its status to a National Park and Reserve covering an area of including as a preserve: However, have been declared as Wilderness. The Glacier Bay also encompasses about of two mining claim groups, and about allotted to Alaska Natives; some small private tracts are also reported within the limits of the Glacier Bay.
The Glacier Bay Basin is now a myriad combination of tidewater glaciers, snow-capped mountain ranges, ocean coastlines, deep fjords, and freshwater rivers and lakes that provide widely varying land and seascape and "hosts a mosaic of plant communities and a variety of marine and terrestrial wildlife."
Glacier Bay is covered with of glaciers which accounts for 27% of the Park area with most glaciers originating in mountains with elevation range of . There are over 50 named glaciers (both tidewater and terrestrial glaciers); 10 tide water glaciers – one on the east arm of the bay and all others on the west arm reach shorelines and calved) (literal meaning: "breaking off") to produce icebergs. Seven of these glaciers are reported to be active tidewater glaciers, which depict the calving phenomenon, which means that they break into icebergs and fall into the sea with thundering noise raising large waves. The McBride Glacier is the only tidewater glacier in the eastern arm at a distance of from Bartlett Cove. Of the other glaciers on the western arm, Johns Hopkins Glacier is at the farthest end – from the entrance to the bay while the Margerie Glacier is about away.
The National Park Service manages a total of of marine waters of the Glacier Bay. It covers a coastline of including some reach of the coast outside the Bay. Glacier Bay Basin as such has a coast line of including all islands; the coast line without counting islands accounts for statute . The deepest point in the bay is below sea level with the diurnal tides occurring every 6 hours, with a tide range of (upper limit of the range is reported to be .
According to the recorded findings, most glaciers are retreating except the Johns Hopkins Glacier, which is advancing and the Margerie Glacier which is stable. The glacier thinning or retreating process is attributed to lesser incidence of snowfall on the hills, raising temperatures in the winter season followed by decrease in cloud cover and precipitation during the summer season.
Post Little Ice Age Rebound in the Glacier Bay Basin has been studied by researchers of the Geophysical Institute, University of Alaska Fairbanks, Alaska in association with National Park and Preserve Service, under a National Science Foundation grant using GPS geodesy combined with studies of raised shorelines and tide gauges. The studies have established that the fastest rates of glacier rebound in the world are now taking place in the Glacier Bay region. The studies have also reported that "these adjustments to LIA loading and unloading are producing significant stresses on the earth's crust which can affect seismicity and regional tectonics. The rising land also is continually changing the geomorphic texture of shoreline throughout the Park and causing changes in hydrologic patterns, erosion, and sedimentation. All these changes have a direct impact on the ecosystems of the Park."
Glacier Bay can be approached only by boats or ships and partly by hiking along three trails () and by kayaking along ) of shore line. The nearest road head and airport are in the small town of Gustavus, which is known as the southern gateway to the Glacier Bay. However, Gustavus as such is approachable only by air and sea. Juneau, the capital of Alaska, is about ). The approximate distance between Anchorage and Juneau is .
The advancing and retreating characteristics of the glaciers in the Glacier Bay are explained in simple terms as a steady state of snow getting converted into ice on the hills. Ice, as a lens of water on the base of bedrock, slides by gravity downwards. The good moraine of rock and rubble insulates it from water erosion. As a result, during freezing temperatures that exists all the year, the glacier advances. When the insulation and erosion effect of the hills gets reduced erosion sets in and along with rising temperatures the glaciers start retreating. Another unpredictable phenomenon that is observed in many glaciers in the Glacier Bay is that of calving. Calving is a process in which blocks of ice get detached or break off from the glacier, irrespective of weather conditions, all the year round, and crash into the sea with thundering noise creating a boiling like turbulence.