 Eastern cone of Mount Young in the Semisopochnoi Caldera. | |
 | |
  Semisopochnoi Location on a map of Alaska | |
| Geography | |
|---|---|
| Location | Bering Sea |
| Coordinates | 51°57′05″N 179°36′03″E / 51.95139°N 179.60083°E |
| Archipelago | Rat Islands |
| Area | 221.59 km2 (85.56 sq mi) |
| Length | 18 km (11.2 mi) |
| Width | 20 km (12 mi) |
| Highest elevation | 1,221 m (4006 ft) |
| Administration | |
 United States | |
| State |  Alaska |
Semisopochnoi Island or Unyak Island (obsolete Russian: Семисопочной, modern Russian: Семисопочный Semisopochny – "having seven hills"; Aleut: Unyax̂[1]) is part of the Rat Islands group in the western Aleutian Islands of Alaska. The island is uninhabited and provides an important nesting area for maritime birds. The island is of volcanic origin, containing several volcanoes including Mount Young. It has a land area of 85.558 square miles (221.59 square km), measuring 11 miles (18 km) in length and 12 miles (20 km) in width.
At 179°46' East (+179.7667) (in the Eastern Hemisphere), the easternmost tip of Semisopochnoi is, by longitude, the easternmost land location in the United States and North America. Semisopochnoi is located 14 minutes (0.2333 degrees) or 9.7 miles (15.6 km) west of the 180th meridian.
- ^ Bergsland, K. (1994). Aleut Dictionary. Fairbanks: Alaska Native Language Center.