At roughly eight kilometers wide, Atafu Atoll is the smallest of
three atolls and one island (Nukunonu and Fakaofo Atolls to the
southeast and Swains Island to the south are not shown) comprising the
Tokelau Islands group located in the southern Pacific Ocean. The
political entity of Tokelau is currently a territory of New Zealand. In
recent years, public referendums on independence within the islands
have been held, but have not received sufficient support to move
forward.
The primary settlement on Atafu is a village located at the
northwestern corner of the atoll-indicated by an area of light gray
dots in this astronaut photograph. The typical ring shape of the atoll
is the result of coral reefs building up around a former volcanic
island. Over geologic time, the central volcano has subsided beneath
the water surface, leaving the fringing reefs and a central lagoon that
contains submerged coral reefs. Erosion and soil development on the
surfaces of the exposed fringing reefs have formed tan to light-brown
beach deposits (southern and western sides of the atoll) and allowed
vegetation to take root (northern and eastern sides of the atoll).
The Tokelau Islands, including Atafu Atoll, suffered significant inundation and erosion during Tropical Cyclone Percy
in 2005. The approximate elevation of Atafu Atoll is only two meters
above the tidal high-water level. Vulnerability to tropical cyclones
and potential sea level rise make the long-term habitability of the
atoll uncertain.
Astronaut photograph ISS018-E-18129
was acquired on January 6, 2009, with a Nikon D2Xs digital camera
fitted with an 800 mm lens, and is provided by the ISS Crew Earth
Observations experiment and the Image Science & Analysis
Laboratory, Johnson Space Center. The image was taken by the Expedition 18 crew. The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program
supports the laboratory to help astronauts take pictures of Earth that
will be of the greatest value to scientists and the public, and to make
those images freely available on the Internet. Additional images taken
by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption William L. Stefanov, NASA-JSC.
- Instrument:
- ISS - Digital Camera