Olosega

Ofu-Olosega
Ofu-Olosega from Space Shuttle.
Highest point
Elevation	639 m (2,096 ft)
Prominence	639 m (2,096 ft)
Coordinates	14°10′30″S 169°37′05″W / 14.175°S 169.618°W / -14.175; -169.618Coordinates: 14°10′30″S 169°37′05″W / 14.175°S 169.618°W / -14.175; -169.618
Geography
Location	American Samoa
Topo map	USGS
Geology
Mountain type	Shield volcanoes
Last eruption	September to November 1866

Ofu and Olosega are parts of a volcanic doublet in the Manu‘a Group of the Samoan Islands—part of American Samoa. The twin islands, formed from shield volcanoes, have a combined length of 6 km and an area of 12 square kilometers (5 square miles); their population is about 500 people. They are geographic volcanic remnants separated by the narrow 137-meter-wide (449-foot) Asaga strait, a natural bridge of shallow coral reef. Before 1970, one had to wade between the two islands at low tide; now a single-lane road bridge over the strait connects villages on Ofu island with those on Olosega.

The highest peak on Ofu is Mount Tumutumu (491 m (1,611 ft), also referred to as Tumu) and the highest elevation on Olosega is Mount Piumafua (629 m (2,064 ft)). The most recent volcanic eruption took place in 1866, 3 km (1.9 mi) south east of Olosega.

Archaeology field work carried out in the 1980s yielded pre-historic evidence including ceramics, adzes, shell and bone which have been significant in furthering understanding of the ancient history of the Samoa Islands and Polynesia. This included samples of red-slipped plainware ceramics that appeared to be in the tradition of the Lapita culture. The work, carried out by a team that included Pacific archaeology specialist Patrick Vinton Kirch, focused on a site called To'aga (site AS-13-1), a 2 km (1.2 mi) coastal stretch on the south coast of Ofu. The results showed continuous human habitation of about 3,000 years.

Ofu is the western part of the volcanic outcrop of Ofu-Olosega Island. The main village of Ofu is located on the western shore, protected behind an offshore islet (eroded tuff cone) known as Nu'utele. Ofu has a small airport (IATA: OFU, ICAO: NSAS) and a boat harbor that serve the population on Ofu and Olosega. Before regular airline service was discontinued in 2009, the flight from Pago Pago took about half an hour.