|
|
Greatest
River....
AMAZON
How Great is the Amazon
River?
The Amazon is the greatest
river in the world by so many measures; the volume of water it carries
to the sea (approximately 20% of all the freshwater discharge into
the oceans), the area of land that drains into it, and its length
and width. It is one of the longest rivers in the world and, depending
upon who you talk to, is anywhere between 6,259km/3,903mi and 6,712km/4,195mi
long.
For the last century the length of the Amazon
and the Nile Rivers have been in a tight battle for title of world's
longest river. The exact length of the two rivers varies over time
and reputable sources disagree as to their actual length. The Nile
River in Africa is reported to be anywhere from at 5,499km/3,437mi
to 6,690km/4,180mi long. But there is no question as to which of
the two great rivers carries the greater volume of water -
the Amazon River.
At its widest point the Amazon River
can be 11km/6.8 mi wide during the dry season. The area covered by the
Amazon River and its tributaries more than triples over the course of
a year. In an average dry season 110,000 square km of land are water-covered,
while in the wet season the flooded area of the Amazon Basin rises to
350,000 square km. When the flood plains and the Amazon River Basin
flood during the rainy season the Amazon River can be up to 40km/24.8
mi wide. Where the Amazon opens at its estuary the river is over 325km/202
mi wide!
Because the Amazon drains the entire
Northern half of the South American continent (approx. 40% landmass),
including all the torrential tropical rains that deluge the rainforests,
it carries an enormous amount of water. The mouth of the Amazon River,
where it meets the sea, is so wide and deep that ocean-going ships have
navigated its waters and traveled as far inland as two-thirds the way
up the entire length of the river.
The
Amazon - Home of Extremes
The
Amazon River is not only the greatest in the world, it is home to many
other "Extremes"  of
the natural world. Have you ever seen a catfish?
They're usually
found in warm, slow moving waters of lakes and streams, and some people
keep them as pets in aquariums. Catfish are pretty creepy looking fish
with big flat heads and "whiskers" on either side of their heads (hence
the name, catfish). Most catfish that we're familiar with here
in the U.S. are anywhere from eight inches long to about five feet,
weighing in at up to 60 pounds. But the catfish that live in the world's
greatest river have all the room in the world to grow as big as nature
will allow - they have been captured weighing over 200 pounds! One of
the largest freshwater fish in the world is found living in the waters
of the Amazon River. Arapaima, also known locally
as Pirarucu, Arapaima gigas are the largest, exclusively fresh
water fish in the world. They have been found to reach a length of 15
ft/4m and can weigh up to 440lbs/200kg. (Read
about the biggest freshwater fish in the world.)
The Amazon
is also home to some other extreme creatures, featured here in "Extreme
Science"; the Anaconda (biggest snake),
and Piranha ( most ferocious).
Check it out!
So, how did the Amazon
get to be so big? The first reason has to do with its location -
right at the equator. Around the "belt line" of the earth lies a
warm, tropical zone where over 400 in/1016cm of rain fall every
year. That averages out to more than an inch (3cm) of rain, everyday!
A lot of water falls onto the land surrounding the river,
what is called the "Amazon River drainage basin". A good way to
understand what a drainage basin is to think of the whole northern
half of the continent of South America as a shallow dish, or saucer.
Whenever rain falls and lands anywhere in the river basin it all
runs into the lowest place in the pan, which happens to be the Amazon
River. The sheer volume of rain in the Amazon jungle, as well as
the slope of the surrounding land, combine to create the enormous
river known as the Amazon.
|
Location: The headwaters
of the Amazon begin high in the Andes Mountains
of South America. The river snakes through the entire northern
half of the continent.
Facts: 4.2 million cubic
feet of water per SECOND empties into the ocean at the mouth of
the Amazon River. During the rainy season that
number goes up to 7 million feet per second!
The Scientists Who Study this Cool
Stuff?
Hydrologists, Biologists, Ichthyologists, Geologists, Entomologists,
Botanists, Zoologists, Herpetologists.
Links:
Wiki
Page on the Amazon
Save
the Amazon Rainforest
Smithsonian
National Zoo
Access
Excellence; River of Venom |
|
