Yale Glacier is a massive tidewater glacier in College Fjord of Prince William Sound that starts at an elevation of 9,270 feet (2,826 m) between Mount Cardozo and Mount Einstein in the Chugach Mountains and flows generally southwest for 17 miles (27 km) to Yale Arm, about 48 miles (77 km) northeast of Whittier and 43 miles (69 km) west-northwest of Valdez, Alaska. The glacier was named for Yale University in New Haven, Connecticut by members of the 1899 Harriman Alaska expedition. The Chugach Mountains of Southcentral Alaska are the northernmost of several mountain ranges that make up the Pacific Coast Ranges of the western edge of North America. The range is about 250 miles (402 km) long and 60 miles (97 km) wide and extends from the Knik and Turnagain Arms of Cook Inlet in the west to Bering Glacier in the east. It is bounded on the north by the Matanuska, Copper, and Chitina Rivers. The highest point of the Chugach Mountains is Mount Marcus Baker at 13,094 feet (3,991 m), but with an average elevation of 4,006 feet (1,221 m), most of its summits are not especially high. Even so, its position along the Gulf of Alaska ensures more snowfall in the Chugach than anywhere else in the world, an annual average of over 800 inches (1500 cm). The name ‘Chugach’ is derived from ‘Cuungaaciq’, the Chugach Sugpiaq word for one of the Alutiiq dialects spoken on the Chugach Islands and the neighboring part of the Kenai Peninsula. Cuungaaciq is actually a place name, referring to several islands in Alutiiq territory. The Chugach Sugpiat people are Alutiiq or Pacific Eskimo who speak the Chugach dialect of the Alutiiq language. In 1898, U.S. Army Captain William R. Abercrombie applied the name ‘Chugatch’ to the mountains surrounding Valdez.

During the Last Glacial Maximum, Prince William Sound was covered by the Cordilleran ice sheet. When the ice sheet receded about 9,000 years ago, people began to migrate into the area, and evidence from a prehistoric village site called Uqciuvit about 25 miles (40 km) southwest of Yale Glacier suggests occupation from around 4,400 years ago. During the Little Ice Age, the mountain glaciers advanced and likely forced the abandonment of the village. In 1794, the glaciers of College Fjord were first reported by Lieutenant Joseph Whidbey, with Captain George Vancouver‘s survey party, who came within about 12 miles (19 km) of the glacier before being blocked by floating ice. In 1887, Samuel Applegate, on the schooner Nellie Juan and surveyed this area but also did not approach the glacier terminus. Applegate’s map of Yale Glacier indicates the glacier terminus was near or just beyond College Point. In 1898, the U.S. Army team of Edward F. Glenn, Joseph C. Castner, and Walter C. Mendenhall approached the huge glaciers at the head of College Fjord on the steamship Valencia and called them ‘Twin Glaciers’. In 1898, the Harriman Expedition on the steamship George W. Elder, named the glacier in the east arm of College Fjord for Yale University. Henry Gannett and Grove Karl Gilbert studied the glaciers as fully as their brief visit permitted and other members of the expedition took many photographs. In 1908 and 1909, the U.S. Geological Survey team of Ulysses S. Grant and Daniel F. Higgins, who were both faculty at Northwestern University, took photographs, made maps, and wrote detailed descriptions of the glacier. In 1937, aerial photographs by Bradford Washburn of the U.S. Geological Survey show the glacier terminus was located at about the same position that it occupied when it was visited by the Harriman Alaska Expedition in 1899. The photograph shows several tributary valley glaciers descending the east wall of the fjord, and the two closest to the terminus were detached from the Yale Glacier. In 2006, Yale Glacier had retreated about 3.7 miles (6 km) from the 1937 position and had thinned substantially, in places by more than 820 feet (250 m). All the eastern tributaries had retreated and were detached from the Yale Glacier. An island and a large area of glacially sculpted bedrock had emerged from the retreating glacier.

The terminus fluctuations of several tidewater glaciers in College Fjord have been monitored since 1931 by surveying, photogrammetry, and most recently by satellite imagery. Observation of two glaciers at the head of College Fjord, Yale and Harvard Glaciers, which parallel each other and are derived from the same snowfield in the Chugach Mountains, suggests that their terminus behavior may be more related to the dynamics of the tidewater glacier cycle rather than directly linked to climate change, although many indirect links exist. Harvard Glacier has been advancing at an average rate of nearly 66 feet (20 m) per year since 1931, while the adjacent Yale Glacier has retreated at approximately 164 feet (50 m) per year during the same period, nearly twice the advance rate of Harvard Glacier. In general, the terminus positions of tidewater glaciers are a result of complex interactions among fjord depth, ice thickness, and calving rate. Tidewater glaciers are known to have a periodic cycle with three distinct phases. The first phase is a period of slow advance during which the glacier moves down the fjord through deep water by pushing or maintaining a submarine moraine in front of the terminus. The moraine is maintained in front of the glacier by continuous erosion along the sides and bottom and deposition at the front that results in greatly reduced iceberg calving. The second phase is a period of relative stability during which the glacier terminus is nearly stationary in the shallow water created by the submarine moraine. The third phase is a period of rapid retreat during which the terminus retreats off its submarine moraine exposing the terminal face to deep water. This causes the calving rate to increase and exceed the rate of ice supply to the terminus which results in a dramatic retreat up the fjord. The retreat will continue until the glacier stabilizes on another submarine shoal or becomes grounded at the head of the fjord where it can begin building another terminal moraine. Yale Glacier appears to be near the completion of the catastrophic retreat phase while Harvard Glacier is in the advancing phase. The cycle may be triggered or intervened by climatic changes since overall warming could limit the ice supply. Read more here and here. Explore more of Yale Glacier here: