image (963 Kb)
In one photograph,
International Space Station astronauts were able to capture the
development and accumulation of coral reefs over geologic time scales
from fringing reefs to atolls. Charles Darwin first developed this
theory while visiting Tahiti using maps made by Captain Cook. In
this image of the Leeward Islands of the Society Archipelago the
islands are progressively older to the northwest. As these islands
move away from their magma sources they erode and subside and the
corals have gradually built the reef structure present today. The
two large islands, Raiatea and Tahaa, share a single fringing reef.
The next island to the northwest, Bora-Bora, consists of a highly
eroded volcanic remnant with fringing reef. The last island, Tupai,
signifies the destiny of these islands; the fringing reef has become
an atoll with the central island below sea level.
The image was
taken in February 2003 from the International Space Station using
a digital camera as part of the Crew
Earth Observations Project. Coral reefs are one of the areas
selected as a scientific theme for this project.
book on coral reefs and their development is still used today and
was reprinted in 1984. See The Structure and Distribution of Coral
Reefs, University of Arizona Press, Tucson, Ariz.
is provided by the Earth Sciences and Image Analysis Laboratory
at Johnson Space Center. 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.