Pacific OceanUnited States
14°10′S 169°37′W
Ofu-Olosega
Part of Manuʻa Islands
Ofu and Olosega are parts of a volcanic doublet in the Manuʻa Islands, which is a part of American Samoa in the Samoan Islands. These twin islands, formed from shield volcanoes, have a combined length of 6 km and a combined area of 12 square kilometers (5 square miles).

Chart
Overview
Ofu and Olosega are parts of a volcanic doublet in the Manuʻa Islands, which is a part of American Samoa in the Samoan Islands. These twin islands, formed from shield volcanoes, have a combined length of 6 km and a combined area of 12 square kilometers (5 square miles). Together, they have a population of about 500 people. Geographically, the islands are volcanic remnants separated by the narrow, 137-meter-wide (449-foot) Āsaga Strait, composed of shallow-water coral reef. Before 1970, people crossed between the two islands by waiting until low tide and then wading across the shallow water of the strait. Since 1970, there has been a bridge over the strait, providing a single-lane road that connects the two islands. The highest peak on Ofu Island is Mount Tumutumu (also called Tumu), at 491 m (1,611 ft). The highest peak on Olosega is Mount Piumafua, at 629 m (2,064 ft). The most recent volcanic eruption was in 1866, 3 km (1.9 mi) southeast of Olosega. Pre-historic artifacts discovered on Ofu by archaeological field work in the 1980s significantly furthered understanding of the ancient history of Ofu in particular, and the Samoa Islands and Polynesia in general. The artifacts include ceramics, adzes, and worked shell and bone pieces. Samples of red-slipped plainware ceramics were found that appear to have been crafted in the tradition of the Lapita culture. The field 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. Dating of the artifacts suggested that Ofu has been continuously inhabited by humans for about 3,000 years.
From Wikipedia, CC BY-SA 4.0
Census, cataloged
- Major islands2
- Minor islands0
- Islets0
- Rocks & skerries0
Major islands
Ofu
- Area
- 7.2 km²
- High point
- 487 m
Ofu and Olosega are parts of a volcanic doublet in the Manuʻa Islands, which is a part of American Samoa in the Samoan Islands. These twin islands, formed from shield volcanoes, have a combined length of 6 km and a combined area of 12 square kilometers (5 square miles).
Olosega
- Area
- 5.2 km²
- High point
- 623 m
Figures
Photographs

Ofu-Olosega, American Samoa. Ofu (left) and Olosega (right) are separated by a narrow strait just left of the center

Aerial view of Ofu-Olosega, American Samoa. Olosega with Olosega Village on the right, Ofu on the left. Both islands are connected via bridge, crossing a narrow strait.

Beach at Ofu, American Samoa. Original Description: Photo of beach at Ofu.

Ofu, Manu‘a Islands, American Samoa; viewed from the village of Sili on Olosega
Ofu, Manu‘a Islands, American Samoa seen from Olosega; National Park of American Samoa

The west coast of Ofu in American Samoa.

Curt Storlazzi, USGS Pacific Coastal and Marine Science Center. Public domain. / Public domain

A montage of corals and coralline algae found on a reef off the north coast of Ofu in American Samoa.

A montage of corals and coralline algae found on a reef off the north coast of Ofu in American Samoa.

Ofu-Olosega, American Samoa

Divers aboard the National Oceanic and Atmospheric Administration survey ship NOAAS Rainier (S 221) assess conditions off the north coast of Olosega in American Samoa before the day's dives.

A boat from the National Oceanic and Atmospheric Administration survey ship NOAAS Rainier (S 221) off the south coast of Ofu in American Samoa, and a diver from the ship installs a temperature recorder on a coral reef there.
Sources
Facts
Photographs
- Ofu Olosega NPS. Peter Craig, National Park Service / Public domain
- Olosega Village Aerial NPS. Peter Craig, National Park Service / Public domain
- Ofu Beach NPS. Peter Craig, National Park Service / Public domain
- AmSamoa Ofu 442. Eric Guinther (talk · contribs) / CC BY-SA 3.0
- AmSamoa Ofu 160. Eric Guinther (talk · contribs) / CC BY-SA 3.0
- Ofu west coast 2023. NOAA Fisheries/Damaris Torres-Puliza / Public domain
- Radon detector setup. Curt Storlazzi, USGS Pacific Coastal and Marine Science Center. Public domain. / Public domain
- Montage 1 corals Ofu 2023. NOAA Fisheries/Damaris Torres-Puliza / Public domain
- Montage 2 corals Ofu 2023. NOAA Fisheries/Damaris Torres-Puliza / Public domain
- Ofu-Olosega. NASA / Public domain
- NOAAS Rainier (S 221) divers assess conditions Olosega 2023. NOAA Fisheries/Ray Boland / Public domain
- NOAAS Rainier (S 221) Ofu boat diver montage 2023. NOAA Fisheries/Morgan Winston / Public domain