Nunivak Island is volcanic in origin; most of the island is dominated by
volcanic plateau 500 ft (160 m) or more above sea level. The island is dotted with about 60
cinder cones and four
maars. Much of its surface consists of widespread, thin flows of
pahoehoe lava from small
shield volcanoes, which spread over
sedimentary rock of the
Cretaceous period. Volcanic eruptions took place during 5 periods of activity beginning 6.1 million years ago. Most of the volcanic field was formed during the two most recent eruptive periods during the
Pleistocene ending about 300,000 years ago. Because of the history of volcanic activity, it is considered part of the
Bering Sea Volcanic Province. The Ibkilwit Lava Bed is located on Nunivak Island.
Tundra is the main landscape feature; the largest trees on Nunivak are dwarf
willow trees, most less than 4 ft (1.2 m) tall. More than 40 rivers drain the tundra upland.
Brackish lagoons ring the eastern and southern shores, and steep, volcanic cliffs dominate the northwest shores. At least 89 migratory
seabird and
waterfowl species have seasonal homes on Nunivak Island, including several endangered and threatened species. Dense summer-breeding
rookeries are found on all shores of the island, and in inland tundra lakes. Prehistorically, Nunivak was home to a modest herd of
caribou, but these were exterminated after the introduction of firearms in the late 19th and early 20th century. The
United States Fish and Wildlife Service introduced
reindeer (the smaller Eurasian caribou) and
musk oxen onto the island in the 1930s and 1940s. Large herds of these animals are maintained by the local Native Corporation of
Mekoryuk. The muskoxen are most valued for their wool, or
qiviut, which is collected after the animals shed in springtime for spinning into yarn, with one skein sometimes selling for $100. Most of the island is part of the
Yukon Delta National Wildlife Refuge, administered by the
U.S. Fish and Wildlife Service. The southern half of the island (600,000 acres) is protected as the Nunivak Wilderness. ==Culture==