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Sahara Sea

Sahara Sea is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sahara Sea rather than just read about it. In short: The Sahara Sea was the name of a hypothetical macro-engineering project which proposed flooding endorheic basins in the Sahara with waters from the Atlantic Ocean or Mediterranean Sea. The goal of this unrealised project was to create an inland sea that would cover the substantial areas of the Sahara that lie below sea level, bringing humid air, rain, and agriculture deep into the desert.

Sahara Sea — main illustration
Sahara Sea — illustration

Key takeaways

  • Sahara Sea belongs to earth science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Sahara Sea to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Sahara Sea from memory before moving on to harder problems.

Reference excerpt

The Sahara Sea was the name of a hypothetical macro-engineering project which proposed flooding endorheic basins in the Sahara with waters from the Atlantic Ocean or Mediterranean Sea. The goal of this unrealised project was to create an inland sea that would cover the substantial areas of the Sahara that lie below sea level, bringing humid air, rain, and agriculture deep into the desert. The possibility of such a project was raised several times by different scientists and engineers during the late 19th century and early 20th century. The concept of a flooded Sahara was also featured in novels of the time. Countries regarding which such a project was discussed include Morocco, Algeria, Tunisia, and Egypt.

History

19th century In 1877, the Scottish entrepreneur and abolitionist Donald Mackenzie was the first to propose the creation of a Sahara Sea. Mackenzie's idea was to cut a channel from one of the sand-barred lagoons north of Cape Juby, south to a large plain which Arab traders had identified to him as El Djouf. Mackenzie believed this vast region was up to 61 metres (200 ft) below sea level and that flooding it would create an inland sea of 155,400 square kilometres (60,000 sq mi) suited to commercial navigation and even agriculture. He further believed that geological evidence suggested this basin had once been connected to the Atlantic via a channel near the Saguia el-Hamra. He proposed that this inland sea, if augmented with a canal, could provide access to the Niger River and the markets and rich resources of West Africa. There are several small depressions in the vicinity of Cape Juby; at 55 m below sea level, the Sebkha Tah is the lowest and largest. But it covers less than 250 km² and is 500 km north of the geographical area identified as El Djouf (also known as the Majabat al-Koubra) which has an average elevation of 320m. Mackenzie never travelled in this area, but he had read of other sub-sea level desert basins in present-day Tunisia, Algeria, and Egypt similar to those found near Cape Juby. These basins contain seasonally dry salt lakes, known as chotts or sebkhas.

François Elie Roudaire, a French geographer, and Ferdinand de Lesseps, a diplomat influential in the creation of the Suez Canal, proposed this area for the creation of an inland sea in 1878. Roudaire and de Lesseps proposed that a channel be cut from the Gulf of Gabès in the Mediterranean to the Chott el Fejej which would allow the sea to drain into these basins. They were not specific in the area such a sea would cover (although subsequent analyses suggested that it would be considerably smaller than Mackenzie's proposal at only 8,000 square kilometres (3,100 sq mi) in area), but argued that the new inland sea would improve the quality of weather on the European continent. The estimated cost of the Roudaire project was $30,000,000 at the time. While Roudaire and de Lesseps were optimistic about the weather effects that such an inland sea would produce in Europe, others were not as hopeful. Alexander William Mitchinson argued that flooding substantial areas would create disease-ridden swamps. Others were critical of the feasibility of the project or the proposal to join the sea at El Djouf with the sea in what is now Tunisia and Algeria. The project was ultimately rejected by the French Government and funding was withdrawn when surveys revealed that many areas were not below sea level as had been believed.

20th century The proposal to create a Sahara Sea was revived in the early 1900s by French professor Edmund Etchegoyen. Around 1910, Etchegoyen proposed that a longer and deeper channel could be constructed. He argued that such a sea could be a boon for colonisation and could potentially produce an inland sea half the size of the Mediterranean. This proposal was considered by the French government but also rejected. Critics noted that, while some parts of the Sahara were indeed below sea level, much of the Sahara was above sea level. This, they said, would produce an irregular sea of bays and coves; it would also be considerably smaller than estimates by Etchegoyen suggested.

The Qattara Depression Project proposed to flood the Qattara Depression in Egypt, producing hydroelectricity and allowing for future salt mining. Discussed as early as 1912, the idea was considered periodically throughout the 20th and early 21st centuries. Operation Plowshare was an American idea to use nuclear explosives in civil engineering projects such as the Qattara Depression Project. It was also suggested that nuclear explosives might be detonated to create a channel from the Mediterranean to the chotts of Tunisia. This proposal was abandoned, however, with the signing of various treaties prohibiting peaceful nuclear explosions.

21st century The project regained steam in the mid 2010s with the creation of the association Cooperation Road which in 2018 obtained the approval of the Tunisian government.

Appearances in literature The notion of a Sahara Sea has been featured several times in literature, most notably in Jules Verne's last novel, Invasion of the Sea, which directly referred to the plan of Roudaire and de Lesseps. The idea of a flooded Sahara also occurs in The Secret People by John Wyndham. In "The Man Who Rocked the Earth" (1915), a man who has harnessed nuclear power blasts through the Atlas Mountains to flood the Sahara. In the 2018 film Aquaman, the Sahara was once a sea inhabited by an Atlantean tribe.

Other desert flooding projects Since the late 19th century there have been proposals to connect Lake Eyre in the South Australian desert to the ocean via canal. In 1905, engineers working on an irrigation canal in southern California accidentally released the waters of the Colorado River into a formerly dry basin, creating a large saline lake known as the Salton Sea. Although the lake has shrunk considerably since its creation, it remains the largest lake in the state of California.

References

Illustrations

Sahara Sea: A relief map of northwestern North Africa
A relief map of northwestern North Africa
Sahara Sea: A relief map of Egypt, with the Qattara Depression shown in blue
A relief map of Egypt, with the Qattara Depression shown in blue
Sahara Sea: Map of Tunisia illustrating the area of Roudaire's proposed Sahara Sea
Map of Tunisia illustrating the area of Roudaire's proposed Sahara Sea
Sahara Sea: Map of the Qattara Depression illustrating the proposed routes of canals or tunnels linking it to the Mediterranean.
Map of the Qattara Depression illustrating the proposed routes of canals or tunnels linking it to the Mediterranean.

Worked examples

Example 1 — a first encounter with Sahara Sea

Start with the simplest possible case. Write down what Sahara Sea claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sahara Sea before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sahara Sea ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sahara Sea

In research
Sahara Sea appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Sahara Sea in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Sahara Sea is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fictional oceans and seas, Macro-engineering, Marginal seas of the Mediterranean, so understanding it makes those chapters shorter.
In everyday life
Look for Sahara Sea outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Sahara Sea in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Sahara Sea means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Sahara Sea out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sahara Sea in simple terms?

The Sahara Sea was the name of a hypothetical macro-engineering project which proposed flooding endorheic basins in the Sahara with waters from the Atlantic Ocean or Mediterranean Sea. The goal of this unrealised project was to create an inland sea that would cover the substantial areas of the Saha…

Why does Sahara Sea matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sahara Sea?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sahara Sea.

Tags

  • Fictional oceans and seas
  • Macro-engineering
  • Marginal seas of the Mediterranean
  • Proposed canals
  • Sahara

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