How deep is the sand in the Sahara?

already exists.

Would you like to merge this question into it?

already exists as an alternate of this question.

Would you like to make it the primary and merge this question into it?

exists and is an alternate of .

I asked a similar question of Dr. Christopher S. Swezey in 2001:

Hi - I recently came across your letter to Science in the 10/8/99
issue and thought you might be able to answer a question I have had
since visiting the Sahara in 1985: how deep is the sand at its
deepest? Or how deep at the greatest depth that has been sampled or
imaged? Are your thermoluminscence data from drilling core samples?

Thanks in advance for satisfying my idle curiosity.
--

Gantt Galloway

Here's the answer he gave me:

Much of the Sahara is characterized by bare rock, and the sand in the
Sahara tends to occur in discrete groups (usually topographic basins).
Large areas covered by sand are called sand seas or "ergs." Within ergs,
however, the amount of sand cover is variable. Dunes take on different
shapes, as a function of wind characteristics and the amount of sand
available. Barchan dunes (small crescentic dunes) form where the wind is
unidirectional and where there is not much sand available. The interdune
areas associated with barchan dunes consist of bare rock or some other
non-sandy substrate. In contrast, star dunes form where the winds are
multidirectional and where there is a lot of sand available.

I am most familiar with the Grand Erg Oriental (Great Eastern Sand Sea) of
Tunisia and Algeria. This erg is characterized by barchan dunes and other
small linear dunes in the north, larger dunes with various linear and
grid-like shapes further south, and star dunes at the extreme southeastern
part of the erg. The tallest star dunes of this erg are 320 m high, and
the interdune areas around the star dunes are filled with sand (Star dunes
in most other regions of the Sahara are not as tall as the star dunes of
the Grand Erg Oriental, so I assume that the sand cover is less thick in
these other regions). I am not certain how thick the sand would be if you
drilled a well in the middle of an interdune area among the Erg Oriental
star dunes (maybe 150 m, maximum?). I do know that the dunes of the Erg
Oriental rest on top of sandstones of Miocene age (~5-23 million years
old), that these sandstones are exposed in the interdune areas to the
north. Some oil companies have drilled wells in the southern part of the
sand sea, but their targets are very deep and they rarely report the
thicknesses of the younger sediments near the surface.

My thermoluminescence dates from the Grand Erg Oriental were from small
outcrops on the northern margin of the erg, where wind-blown sand deposits
interfinger with lake and river deposits. I chose this area because it is
a basin that lies below sea level, and is still subsiding. I thought that
this might have the oldest record of wind-blown sediments in the Sahara. I
found out, however, that most of these sediments are relatively young
(<18,000 years old), and that these relatively young sediments rest
directly on top of much older Miocene sandstones. This pattern of
relatively young sediments (thousands of years old) resting on top of much
older sandstones (millions of years old) is consistent with what is
observed in most of the rest of the Sahara. If I were to go back to the
Sahara today and look for the oldest record of wind-blown sand, I would
probably look in the area of Lake Chad (another basin that is subsiding,
and filling up with sediments).

Anyway, that may be more information that you wanted. I did most of my
work in the Sahara when I was in graduate school (Univ. of Texas at Austin,
and Univ. Louis Pasteur in Strasbourg - France). When I wrote the letter
to Science, I was employed by British Petroleum in Texas, but about a year
and a half ago I quit BP and took a job with the U. S. Geological Survey.
I am currently working on putting together a story on the origin of the
Sahara Desert, and I am also working on various projects associated with
the Appalachians.

Thanks for contacting me, and let me know if you have any other questions.

- Chris.
9 people found this useful

What percent of the Sahara desert is covered by sand?

searching the web for an answer to the same question, I found this: http://www.pbs.org/wnet/africa/explore/sahara/sahara_topography_lo.html so, it seems the percentage of sand desert amount to 20. I hope this results to be useful. bye. Seem to remember it being between 12% and 20% sand the rest (MORE)

How much sand is need to cover 700 square feet 1 inch deep?

700 sq feet converted to cubic feet is 58.333 (double check that?) convert that to gallons and you get- (this I know is true.) 436.5 gallons, rounded up.. I was told that a 50 lb. bag of sand would cover 6 square feet 1 inch deep. So, divide 700/6 and you get 117. It would take 117 50 lb. ba (MORE)

How does the sand fox adapt the Sahara desert?

The sand fox is nocturnal so it operates during the cool portion of the day rather than traveling in the scorching sun. It has developed large ears to improve its ability to cool itself as canine animals don't sweat like we do. and it burrows underground to keep it cool when it is sleeping. They fav (MORE)

Who sand Deep Purple in 1940s?

Bing Crosby I believe. The song was Ritchie Blackmore's grandmother's favourite song, which is how the band Deep Purple got their name.. Well, actually, there were several versions of the song recorded between 1933 and the early 1980s, but Bing never had a big hit with it. It was, however Ritchie's (MORE)

How many sand dunes are in the sahara desert?

There is no way to answer that question. The Sahara is immense and it would take thousands of people to inventory all the dunes. Also, dunes are constantly changing with the wind. Some disappear, some combine with other dunes and some split from other dunes.

Is the Sahara Desert the only desert with sand seas in it's terrain?

I think (if you mean the only desert with sand dunes everywhere) that the Sahara isn't. I've seen pictures of deserts with sand dunes everywhere, and most of them weren't the Sahara. However, if your talking about its size, the Sahara is the largest (hot) desert on Earth.

Can you sand out deep scratches in bamboo flooring?

Bamboo is really hard to repair. It can be done, but only by an experienced pro. Bamboo is actually a grass that has been pressed. It burns very easily when sanded. Also, you cannot use most wood fillers on it, in addition to its unusual color that would be hard to match.

How far will .74 cubic yards of sand spread at 4 inches deep?

0.74 cubic yards spread at 4 inches (1/9 of a yard) means 0.74 divided by (1/9) = 6.66 square yards, so the answer will depend on how wide the path is. So now you would have to divide 6.66 by the width of the path. This is about 5.5 square metres. So on a path 2 feet wide is would spread 9.99 yards (MORE)

How deep is the sand in the Mojave Desert?

It varies but much of the desert is simply rock, or soil baked into a hard surface. However, the Kelso Dunes in the Mojave National Preserve have reached a height of up to 650 feet (200 meters). This is an unusually large sand formation.

Will three yards of sand cover 54 sq feet 16 inches deep?

If the question refers to 3 cubic yards of sand then all measurements need to be converted to a common unit for the calculation to be made. Let the chosen unit be feet. 1 cubic yard = 3 x 3 x 3 = 27 cu ft : 3 cubic yards = 3 x 27 = 81 cu ft. 12 inches = 1 foot : 16 inches = 16 / 12 = 1.333 feet. (MORE)

Can you give me a BIG paragraph about the sand storm in the Sahara desert?

A dust storm or sand storm is ameteorological phenomenon common in aridand semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, a process that moves soil from one place and (MORE)

How much sand is needed to cover an area 24ft around by 2 inches deep?

You have the circumference which is given by pi x d. Rounding 24/3 gives you a diameter of 8 feet. Surface area is pi x r x r for 192 square feet. Convert 2 inches to feet gives 1/6 th of a foot divide into 192 gives 32 cubic feet. There is 27 cubic feet in a cubic yard so slightly over.