Aialik Glacier flows southeast for 8 miles (13 km) from the Harding Icefield in the Kenai Mountains to tidewater at Aialik Bay in Kenai Fjords National Park, about 66 miles (106 km) east-northeast of Homer and 16 miles (26 km) southwest of Seward, Alaska. Named in 1909 by US Geological Survey researchers Grant and Higgins, the glacier takes its name from the bay, which in turn derives from the Alutiiq word ‘Ayalikskaya’ recorded by Russian fur traders. The fjord—about 5 miles (8 km) wide—extends 22 miles (35 km) south from the glacier’s terminus to the Gulf of Alaska and reaches depths of 966 feet (294 m). Its shoreline is indented by numerous bays and coves formed by drowned, glacier-carved cirques. The surrounding bedrock consists mainly of rocks from the Chugach terrane. A portion of this terrane includes fine sediments of the Valdez Group, which filled an ocean trench and lithified as turbidites 75–55 million years ago. These were later intruded by igneous oceanic basalts and, following accretion to the North American Plate, by granitic plutons around 55 million years ago. The Valdez Group—a widespread unit along Southcentral Alaska’s coast—comprises highly deformed, partially metamorphosed sedimentary rocks such as graywacke, siltstone, and shale. Turbidite layers range from a few inches to several feet thick, with some beds tens of feet thick. Aialik Bay is flanked by the Harris Peninsula to the west and the Aialik Peninsula to the east. Along the east, the Aialik Pluton appears as granitic outcrops on offshore islands and extends more than 37 miles (60 km) north into the Harding Icefield, where it emerges in numerous nunataks. During the Last Glacial Maximum, the Harding Icefield formed part of a Cordilleran ice sheet that once covered much of Alaska and North America. This ended about 10,000 years ago with a shift to warmer Holocene conditions and alternating intervals of warming and cooling. The final cooling phase—the Little Ice Age (c. 1350–1850 AD)—left behind today’s Aialik glaciers.

Early humans followed retreating glaciers and settled along the ice-free coastal fringe. Two prehistoric settlements in the Kenai Peninsula fjords are known: Northwestern Lagoon, occupied between 1225 and 1750 AD, and McArthur Pass, occupied between 250 and 1400 AD. Russian fur traders recorded villages such as Yalik Village in Nuka Bay and an unnamed settlement at Verdant Cove in Aialik Bay. In 1793, a Russian fort was built at Voskresenskii near present-day Seward in Resurrection Bay. Outer coast Indigenous residents worked at Voskresenskii, traded furs, and joined annual Russian-organized kayak fleets dispatched during the 1790s and early 1800s to hunt sea otters along the Kenai Peninsula, Prince William Sound, and the eastern mainland. In 1794, Captain George Vancouver encountered one such flotilla of over 400 men. Early Russian fur traders imposed universal service on the Alutiiq: half the men aged 18 to 50 could be conscripted for up to three years to hunt sea otters. In practice, most able-bodied individuals—men, women and children—were required to hunt, fish, trap, harvest birds, prepare food, make clothing, or tan skins for company use. When Russian Orthodox missionaries arrived in the early 1800s and witnessed these hardships, reforms soon followed. By 1844, labor documents described the outer Kenai Alutiiq as semi-dependent, meaning the Russian-American Company had little real control. Hunters were paid in tobacco, beads, iron, copper and other imported goods rather than being subject to impressment. Archaeologists excavated the Aialik settlement, uncovering a midden mound, seven house depressions, four cache pits and two above‑ground sod‑wall features. The findings suggest the site housed 40 or more people in a mix of above‑ground summer houses and semi-subterranean winter houses. The settlement appears to have been short‑lived, likely established in response to the Russian fort and trading center in Resurrection Bay before residents moved closer to the post.

Aialik Glacier reaches tidewater at the head of Aialik Bay. Terminal moraine shoals—sills only 30 ft (9 m) deep—stretch across the bay near Pederson Lagoon, about 5 mi (8 km) south of the current terminus, marking a former extent. The glacial front is a 200‑ft (61 m) ice cliff that discharges ice continuously, with peak calving in summer. Although retreating, Aialik Glacier recedes far more slowly than others in Kenai Fjords because its accumulation far exceeds its ablation zone. The glacier covers 17,297 acres (7,000 ha), with 15,321 acres (6,200 ha) in accumulation and 1,977 acres (800 ha) in ablation. Its terminus is 0.4 mi (0.6 km) wide. In 1909, Ulysses S. Grant and Daniel F. Higgins photographed the terminus and noted a retreat of up to 1,312 ft (400 m) in the prior decade. Between 1950 and 1964 it receded 984 ft (300 m); by the 1990s an additional 787 ft (240 m) was lost. The retreat of Kenai Fjords’ glaciers has exposed a rocky, precipitous coastline with deep-water fjords that attract harbor seals. These seals favor calving tidewater glaciers for hauling out on floating ice, whose availability depends on glacier and fjord morphology, calving rates, currents, weather, water temperatures and season. Floating ice peaks in spring and dwindles by summer. Unlike tidal habitats, ice offers multiple haulout points, allowing seals to group for enhanced vigilance without overcrowding. Ice calved from Aialik Glacier circulates around Squab Island, about 1.2 mi (2 km) east of the terminus, usually remaining north of the sill at Pederson Lagoon. Although Kenai Fjords supports high densities of harbor seals—with several hundred in Aialik Bay—climate change is reducing floating glacier ice. From 1979 to 2009, the number of seals using glacial ice near Aialik fell by 93%. Read more here and here. Explore more of Aialik Bay and Kenai Fjords National Park here: