Grewingk Creek flows for 3.5 miles (5.6 km) from a lake, formed by the retreating Grewingk Glacier, to the southern shore of Kachemak Bay about 13 miles (21 km) east of Homer and 4 miles (6.5 km) north-northeast of Halibut Cove, Alaska. Grewingk Glacier is located on the Kenai Peninsula and trends northwest for about 12 miles (19 km) to its terminus lake. The glacier and creek were named in 1880 by W.H. Dall, of the U.S. Coast and Geodetic Survey for Constantin Grewingk who in 1850, published work in German on the geology and volcanism of Alaska.
Retreating glaciers generally produce high river discharges, large volumes of sediment, and steep channel slopes. Rivers emanating from these glaciers respond to the discharge processes by developing a braided river pattern with multiple channels separated by bars or islands. Braided channel systems are high energy and variable so that channel configurations are constantly changing. Three factors are probably necessary for braiding to occur: 1) an abundant sediment supply, 2) erodible banks, and 3) high stream energy.
When glacial rivers reach the sea the resulting beach sediments can also be highly dynamic with erosion events caused by storm-driven waves and deposition events caused by glacier surges and retreats. In Kachemak Bay, during periods of relative sediment stability, animals such as barnacles and blue mussel, and plants such as rockweed and sea lettuce, colonize the beach face creating multi-colored patterns. Read more here and here. Explore more of Grewingk Creek here: