When you arrive at the canyon, as you have no idea it is there. It
drops vertically by half a kilometre, out of a flat arid plateau
without any warning. As with most rivers in Namibia the Fish River
is generally dry however in the raining season (January to April)
the river can become a raging torrent. The official view points can
be found around Hobas, a camp site, 70 km north of Ai-Ais. From the
parking lot it is just a short distance to the viewing area, also
accessible for wheelchairs.
WARNING. Fish River Canyon has a steep
cliff. Do not approach the edge.
Keep children under close supervision at all
times.
The Fish River Canyon in Namibia is reputedly the second largest
canyon in the world and is absolutely magnificent and breathtaking
in its immensity. It features a gigantic ravine, in total about 180
km long, up to 27 km wide and in places almost 550 metres deep. It
has been gouged out of the surface of the land in the course 650
million years by the forces of water, wind and gravity. However the
canyon was not only created by water erosion, but through the
collapse of the valley bottom due to movements in the earth's
crust. The river cuts deep into the plateau which is today dry,
stony and sparsely covered with hardy drought resistant plants such
as succulents. At the lower end of the Fish River Canyon, the hot
springs resort of Ai-Ais provides an oasis in the desolate rocky
wastes.
Requirements for claiming this Cache
To get credit for this Earthcache please
answer the following Study Questions and email us your findings. It
would be nice if you post a picture of the Fish River Canyon in the
background. Please do not post any answers with your
log.
Study Questions:
1. Describe in your own words how a Canyon is formed by fast
flowing water.
2. There are three main colours of rock formations, what are
those colours?
3. At the bottom of the Canyon, hot springs can be found. Which
chemical element can be found in those springs?
4. The decent into the canyon is very steep; therefore some
sections have a handrail. What is the handrail made of?
5. The Ministry of Wildlife, Conservation and Tourism requires a
certificate before hiking the Canyon. What kind of certificate is
required?
6. Why is the Canyon closed for hikers in summer time? Do you
know both reasons?
Geology
Formation started about 1.8 million years ago with sandstone,
shale and lava deposits which compressed and heated up to over
600°C. The metamorphosed rock re-crystallised and changed
appearance. Dolorite lava, which never reached the surface, cut
through in dark black lines about 650-900 million years ago, and
the first major period of erosion started soon after, exposing and
levelling the rocks. This became the floor of a shallow sea that
covered the southern part of Namibia, upon which sediments were
deposited. The base of the Nama sediments is only a few metres
thick and consists of small pebble conglomerate. Above this are
150-200m (487-650 ft) of black limestone, grit and sandstones.
These are capped by 10 metres (32 ft) of shale and sandstone.
Fracturing of the crust about 500 million years ago formed a
north-south valley and slow erosion removed the upper layers. Then
about 300 million years ago glaciers of the Dwyka Ice Age and
another period of fractures deepened the valley. Through these
faults emerged ground water, bubbling up as hot springs. Most of
the striking features of the canyon developed over the past 50
million years, and today it is one of the most scenic and
impressive canyons in the world.
Other Information
The Fish River Canyon area has a typical semi-desert climate.
During the hot summer months (October - March) temperatures can
rise up to 48 degrees Celsius during the day and cools down to
about 30 °C at night. Relief from the heat comes in short spells
with occasional thunder storms. The average annual rainfall in the
canyon area is 100 mm. During the short winters, temperatures can
go down below zero at night, but quickly picks up during the day to
a moderate 20 to 28 °C.
There is a five-day Fish River Canyon Hike is one of the most
popular hikes in Namibia. The 85km trail starts from the view site
situated on the lip of the Canyon about 12kms from the Namibia
Wildlife Resorts camping site at Hobas, takes 5 days, with
absolutely no facilities whatsoever. You have only what you carry
on your back and whatever water you can find in semi-permanent
pools. From the view site, the hikers descend steeply down the side
of the Canyon for one to two hours dependant on how one's knees can
take the pressure. Some sections at the beginning of this downhill
are extremely steep and have a handrail to help. The hike ends at
the hot springs of Ai-Ais and is only open between 15th April and
15th September. Bear in mind that you must book the trail well in
advance, and you need a certificate before being allowed to
commence the walk.
Links and Resources
Canyon
Formation:
Fish River
Canyon:
Fish River
Canyon Hike:
Fish
River Canyon Hike:
Fish
River, Ai-Ais, and Hobas:
