The image above
is a mosaic of the following 3 images:
image (113 Kb)
High-resolution image (110 Kb)
High-resolution image (93 Kb)
Why are cities
established where they are? How do local economies and politics
influence patterns of human settlement and development at such a
grand scale that these patterns can be identified from space? This
mosaic of images of Johannesburg, South Africa, taken from the International
Space Station illustrates the human geography of the region.
In this case,
the cityscape of Johannesburg is the most difficult pattern to discern.
The center of Johannesburg is the fine-grained pattern -- created
by shadows cast from the high rise buildings in the city -- in the
center of this mosaic. On the southern fringe of Johannesburg a
line of light colored, angular patches, known as the great "mine
dumps", stretch across the scene. These patches are the crushed
rock that remains after gold extraction from numerous gold mines.
These mines underpinned the South African economy for decades --
and their dumps, or tailings piles -- are the visuals that orbiting
crews see when they overfly Johannesburg and neighboring cities,
delineating the east-west outcrop of the gold-rich rock strata discovered
in 1886. Some mine dumps are so large that an outdoor movie theater
was located on one of them. Neighboring industrial cities are nestled
among the mine dumps as far as the edges of the mosaic. Older mine
dumps nearer the Johannesburg city center have disappeared from
view in the last 25 years, having been re-mined for the gold that
remained within them.
The green zone,
located in the top middle, is the leafy northern suburbs, where
hundreds of square miles of grassland have been progressively forested
since Johannesburg was founded in 1886. Small light patches within
the tree-rich zone are satellite business and shopping centers.
By contrast, major ghettoes established by the former South African
government, typical of developing-world urban migration, appear
as grey zones lower left (the famous Soweto Township) with a smaller
ghetto top right (Alexandra Township). Soweto appears largely treeless
except for protected valley bottoms.
are 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.