Stardust Bay, Sedanka Island


Stardust Bay, Sedanka Island

by | May 24, 2018

Stardust Bay is on the southeast coast of Sedanka Island, about 16 miles (26 km) southeast of Dutch Harbor, Alaska. Stardust Bay is named for a fishing vessel wrecked on the steep, high energy beach, at the head of a funnel-shaped embayment exposed toward the Aleutian Trench. This bay is the site of an ongoing study by the U.S. Geological Survey of very large tsunamis.

Sedanka Island is about 11 miles (18 km) long, and located in the Fox Islands off the northeast coast of Unalaska Island, in the Eastern Aleutians, Alaska. In 1792 Lieutenant Sarichev, of the Imperial Russian Navy, named the island “Spirkin”, but that same year Martin Sauer gave the Aleut name “Sithanak” which Marcus Baker recorded “Siginak” meaning “braided” or “curled”. The U.S. Coast and Geodetic Survey named the island “Sedanka” on charts from 1921. Sedanka is uninhabited, but an Aleut village called Biorka was on the north coast until 1942 when it was evacuated during World War II and later abandoned.

Core samples and shallow pits revealed a series of sand deposits from historical tsunamis that reached 0.5 miles (800 m) inland. Drift logs ringing the lowland floodplain approximate the landward limit of the most recent tsunami. The highest log found (a 10 m long by 0.25 m diameter pole) was nearly 0.6 miles (1 km) inland, bridging a narrow gully at an elevation of 60 feet (18.5 m). The drift logs came from Stardust Bay’s shoreline because driftwood litters the beach and, like other Aleutian islands, no trees grow on Sedanka Island. The evidence suggests that intervals between historical tsunamis were as short as 170 years and as long as 570 years. On average, tsunamis of the past 1700 years inundated Stardust Bay every 300–340 years. Learn more about the study here and here. Explore more of Stardust Bay and Sedanka Island here:

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