Anchor Glacier flows east for 3 miles (5 km) to Northwestern Fjord, which is located approximately 52 miles (84 km) east-northeast of Homer and 32 miles (52 km) southwest of Seward, Alaska. The ice stream starts at an elevation of about 5,700 feet (1,737 m) on the eastern flank of McCarty Ridge in the Kenai Mountains. Northwestern Fjord stretches north for 10 miles (16 km) from Harris Bay on the Gulf of Alaska coast within Kenai Fjords National Park. The fjord was named in 1909 for Northwestern University by Ulysses S. Grant and Daniel F. Higgins of the U.S. Geological Survey. Harris Bay was named after Abram W. Harris, president of Northwestern University from 1906 to 1916. As late as 1900, Northwestern Glacier filled the fjord, terminating at a terminal moraine that partially encloses the inlet at the head of Harris Bay. Between 1894 and 1960, the glacier retreated dramatically by 9.4 miles (15 km), revealing bedrock composed of granite and granodiorite. This bedrock is part of a large batholith formed from an igneous intrusion during the Paleocene and Eocene epochs, approximately 60 to 40 million years ago. The batholith stretches from Nuka Bay in the west to Aialik Bay in the east, encompassing offshore islands. It extends north under the Harding Icefield, where it is visible as numerous nunataks.

In 1909, Grant and Higgins observed that Northwestern Glacier had retreated to about 1,200 feet (365 m) from the terminal moraine. By 1928, a U.S. Coast and Geodetic Survey hydrographic survey indicated that the glacier ended approximately 0.5 miles (0.8 km) from the moraine shoal, at a point where the water now reaches a maximum depth of 400 feet (122 m). By 1942, photographs taken by the Army Air Force for reconnaissance mapping showed the glacier had retreated about 4 miles (6.4 km), terminating in a high, irregular ice cliff. A deep, concave embayment had formed near the northern side, where the fjord currently has a maximum depth of 965 feet (294 m). The retreat continued and by 1950, when the U.S. Geological Survey photographed the area for topographic mapping, the glacier ended in a long, concave front extending from rocks west of Erratic Island to Striation Island, and as a high ice cliff blocking Polished Passage north of the island. By 1960, the glacier had retreated an additional 2.5 miles (4 km), and it then terminated at a retracted, stable position near the head of tidewater.

In 1980, Austin S. Post of the U.S. Geological Survey named two tributary glaciers, Anchor Glacier and Ogive Glacier, on the western shore of the fjord exposed by the retreat of Northwestern Glacier. Post was a renowned mountaineer, glacier photographer, and scientist. He was among the first to propose that the water depth at a glacier’s calving margin significantly affects the rate of iceberg calving. This insight contributed to a better understanding of the tidewater glacier cycle. The ongoing retreat of the Ogive and Anchor Glaciers has led to the separation of their termini. Currently, the Anchor Glacier reaches tidewater approximately 4 miles (6.5 km) south of the Northwestern Glacier’s terminus. Many other glaciers that were tributaries to the lower part of the Northwestern Glacier at the turn of the 20th century have now become small, relict ice patches stranded high above the fjord. Read more here and here. Explore more of Anchor Glacier and Northwestern Fjord here: