Meares Glacier starts at an elevation of about 7200 feet (2195 m) in the Chugach Mountains between Mount Michelson to the north and Columbia Peak to the south and trends generally southwest for 16 miles (26 km) to Unakwik Inlet in Prince William Sound, about 47 miles (76 km) northeast of Whittier and 40 miles (64 km) west of Valdez, Alaska. This tidewater glacier was named in 1909 by Ulysses S. Grant and Daniel F. Higgins of the US Geological Survey in honor of 18th-century British naval captain John Meares, a noted Pacific Northwest explorer and fur trader. Meares spent the winter of 1786-87 in Prince William Sound during a trading expedition aboard the English vessel Nootka. Unakwik Inlet extends northward for about 22 miles (35 km) from the main body of Prince William Sound. The Alutiiq name was first recorded in 1898 as “Unaguig Inlet” by U.S. Army Captain Edwin F. Glenn; the spelling was revised in 1909 by Grant and Higgins. The fjord is 1 to 3 miles wide (1.6-4.8 km), with water depths ranging from 534 feet (163 m) at the glacier terminus to over 1,000 feet (305 m) near the inlet entrance. However, the depth shoals to just 6 feet (1.8 m) at an ancient terminal moraine, likely marking the maximum ice advance during the Holocene Neoglacial period. Prince William Sound’s geology features one of the world’s largest accretionary complexes, known variously as the Chugach terrane, Chugach and Prince William terranes, and most recently, the Southern Margin Composite terrane. This terrane comprises rocks from the Late Cretaceous and Paleogene periods, represented by the Valdez Group north of the Contact Fault at Miners Bay in upper Unakwik Inlet and underlying Meares Glacier. These rocks are primarily complexly deformed metasedimentary graywacke, siltstone, and shale, generally considered deposits from turbidity currents in a deep oceanic trench.

The heavily glaciated north coast of Prince William Sound experienced repeated ice advances during the Neoglacial Period. Despite this hostile environment, humans have inhabited the area for thousands of years. The earliest known occupation of the sound is based on archaeological excavations at a prehistoric village site called Uqciuvit, located at the northern end of Esther Passage in Port Wells, about 16 miles (26 km) west of Unakwik Inlet. This village was inhabited between approximately 4,400 and 3,300 years ago. Little is known about the people of this pre-Neoglacial phase, except that they hunted sea mammals, used red ochre, and were familiar with slate grinding. Historically, Prince William Sound was home to eight geographic groups of Chugach people, the easternmost group of Eskimos. Although these groups shared the same language and culture, each was politically independent, with its own leader and principal village. The Kiniklik people people were one of the original Chugach tribes. In 1956, Frederica de Laguna inventoried the settlements of Prince William Sound based on surveys from 1930 and 1933. She described a prehistoric village of the Kiniklik people in Unakwik Inlet on the west shore near the fjord’s mouth. The main historical village, also named Kiniklik, was located at the peninsula’s end separating Unakwik Inlet from Eaglek Bay to the west and was already abandoned by 1930. In 1790, Spanish explorer Salvador Fidalgo reputedly visited Unakwik Fjord. In 1794, Lieutenant Joseph Whidbey, with the Vancouver Expedition, sailed into the bay and found the upper part blocked by ice. He noted the noise of ice falling from the glacier front. In 1905, Grant and Higgins visited the bay and returned in 1909 to document the glacier. They photographed the terminus, describing it as 0.8 miles (1.3 km) wide and over 300 feet (91 m) high, and noted it was slowly advancing as vegetation was being overrun by ice.

Meares Glacier has been advancing since it was first observed in 1905. William O. Field reported that between 1910 and 1931, the glacier’s terminus advanced 820 to 985 feet (250 to 300 m), with an annual advance of 40 to 50 feet (12 to 14 m). From 1931 to 1966, it advanced 650 to 1,400 feet (200 to 425 m), or 20 to 40 feet (6 to 12 m) annually. Over the 56 years from 1910 to 1966, the terminus advanced 1,640 to 2,215 feet (500 to 675 m), averaging 30 to 40 feet (9 to 12 m) per year. In 1910, Ernest F. Bean, part of a National Geographic Society expedition, found water depths ranging from 634 feet (193 m) about 0.5 miles (0.8 km) south of the terminus to over 1,000 feet (305 m) near the inlet’s entrance. He also identified evidence of past glaciations. The fjord walls are straight and steep, with numerous hanging valleys where streams cascade to the sea. The rock walls display ice grooving, plucking, and striation. Bathymetric soundings confirmed that Meares Glacier once extended farther south, eroding the inlet. Bean determined that the depth was too shallow at the terminus for the glacier to be floating, indicating it was actively scouring the inlet floor. The ice front height is at least 200 feet (61 m), and the water depth is 634 feet (193 m), giving a total thickness of 734 feet (224 m). For glacier ice to float in seawater, one-sixth of its volume must be above water, requiring a total thickness of 1,200 feet (366 m). In 2000, Meares Glacier’s terminus was observed to be slowly advancing and pushing down trees, although aerial observations showed ice thinning at the margins. From 1910 to 2000, the terminus advanced about 0.7 miles (1.1 km), averaging 40 feet (12.2 m) per year. Between 1966 and 2002, the glacier advanced about 1,800 feet (550 m), averaging 50 feet (15 m) annually. This atypical advance is due to the large snow accumulation zone of 30,000 acres (12,140 ha) compared to the ablation zone of 5,000 acres (2,000 ha). Read more here and here. Explore more of Meares Glacier and Unakwik Inlet here: