The Victoria Falls or Mosi-oa-Tunya (the Smoke that Thunders, and
note that the 'i' is silent) is a waterfall located in southern Africa
on the Zambezi River between the countries of Zambia and Zimbabwe.
It
is claimed to be the largest. This claim is based on a width of 1,708
metres (5,604 ft) and height of 108 metres (354 ft), forming the largest
sheet of falling water in the world. The falls' maximum flow rate
compares well with that of other major waterfalls.
For
a considerable distance upstream from the falls, the Zambezi flows over
a level sheet of basalt, in a shallow valley bounded by low and distant
sandstone hills. The river's course is dotted with numerous
tree-covered islands, which increase in number as the river approaches
the falls. There are no mountains, escarpments, or deep valleys which
might be expected to create a waterfall, only flat plateau extending
hundreds of kilometres in all directions.
The falls
are formed as the full width of the river plummets in a single vertical
drop into a transverse chasm 1708 metres (5604 ft) wide, carved by its
waters along a fracture zone in the basalt plateau. The depth of the
chasm, called the First Gorge, varies from 80 metres (260 ft) at its
western end to 108 metres (354 ft) in the centre. The only outlet to the
First Gorge is a 110 metres (360 ft) wide gap about two-thirds of the
way across the width of the falls from the western end, through which
the whole volume of the river pours into the Victoria Falls gorges.
There
are two islands on the crest of the falls that are large enough to
divide the curtain of water even at full flood: Boaruka Island (or
Cataract Island) near the western bank, and Livingstone Island near the
middle — the place that David Livingstone first saw the falls from in
Zambia. At less than full flood, additional islets divide the curtain of
water into separate parallel streams. The main streams are named, in
order from Zimbabwe (west) to Zambia (east): Devil's Cataract (called
Leaping Water by some), Main Falls, Rainbow Falls (the highest) and the
Eastern Cataract.
