The Iguassu Waterfalls are situated inside
the Iguassu National Park. (latitude: 25Ȱ 41' S :: longitude: 54
26' W )
The Iguassu National Park (Brazil) was created
by Brazil federal decree on the 10th January 1939. The Park
contains the area of 185,000 hectares of subtropical rain forest. The national
park was declared by UNESCO as Natural Heritage of Mankind site in 17th November 1986. Waterfalls consist of 275 single falls on the Brazilian
and Argentinian side of the Iguassu River. The waterfalls were most probably initially located
at the confluence of the Iguaz and Parana Rivers some 20,000 years ago,
but erosion has caused them to recede 28 km upstream to their present location
at the altitude of 150 m. The area of waterfalls is part of a large
plateau formed by basaltic lavas during the Mesozoic Era, more than 150
million years ago. Lava surfaced through tectonic faults and cracks, without
formation of volcanic cones, and covered some one million square kilometres.
There are only 3 larger waterfalls on the Brazilian
side of 19 larger together. The Guarani word 'Iguassu' means 'Great Water'.
The river rises in the area of Serra do Mar and runs for 1320 km through
the state of Paran before it flows into the Paran River at Puerto do
Iguazu where are three borders of Argentina, Brazil and Paraguay.
The width of the falls (2700 m)
is 800 m on the Brazilian side and 1900
m on the Argentinean side. Including a rapid above the falls, the
height is 72 m (their height varies between 40 and 90m). Depending
on the season of the year (rain fall) the water flow varies between
300 cubic metres/sec and 6500 cubic metres/sec with an average flow
of 1500 cubic metres/sec.