Grewingk Glacier is on the Kenai Peninsula and flows northwest for 11 miles (18 km) from the Kenai Icefield to its terminus at a proglacial lake in Kachemak Bay State Park about 5 miles (8 km) southwest of Kachemak Bay, and 16 miles (25 km) east-southeast of Homer, Alaska. Grewingk Creek drains the lake and flows 3 miles (4.8 km) to Kachemak Bay. The glacier was named by William Healey Dall of the U.S. Coast and Geodetic Survey in 1880 for Constantin Grewingk who in 1850, published work in German on the geology and volcanism of Alaska.
There are several named glaciers on the southeastern side of Kachemak Bay which approach but no longer reach tidewater. These include from south to north remnants of the Southern Glacier that drains into Tutka Bay, Doroshin and Wosnesenski Glaciers that drain into Neptune Bay, Grewingk Glacier, Portlock Glacier that drains into Kachemak Bay just north of Mallard Bay, Dixon Glacier that drains into Kachemak Bay via the Martin River, Kachemak Glacier that drains into Bradley Lake, Dinglestadt Glacier that drains into Kachemak Bay via the Sheep River, and the Chernof Glacier that drains into Kachemak Bay via the Fox River. These are the most westerly glaciers on the Kenai Peninsula. From 1950 to 2005 at least 27 glaciers in the Kenai Icefield region were retreating, and the Grewingk Glacier had retreated 1.5 miles (2.5 km).
Grewingk Glacier was visited by W.H. Dall in 1880, 1892, and 1895. The results of his mapping of this glacier were incorporated in charts of the U.S. Coast and Geodetic Survey. Dall visited the Grewingk Glacier again in 1899 with Grove Karl Gilbert, a geologist on the Harriman Expedition, who provided a detailed description of the glacier. The Grewingk ice front continues to calve into an expanding pro-glacial lake that is currently about 2 miles (3.2 km) long. Between 1986 and 2014, the glacier had retreated 0.9 miles (1.4 km) or about 164 feet (50 m) per year. There was also an increase in the glacier slope 1.5 miles (2.5 km) above the terminus where crevassing increases. This suggests the lake will end at this point, which should cause a reduction in retreat rate. The loss of glacial ice may have triggered a massive landslide of 2,966 million cubic feet (84 million cubic meters) of rock and debris, creating a tsunami that swept the forefield of Grewingk Glacier in the fall of 1967. Read more here and here. Explore more of Grewingk Glacier here: