Red Sea

Ancient era

The earliest known exploration of the Red Sea was conducted by ancient Egyptians, as they attempted to establish commercial routes to Punt. One such expedition took place around 2500 BC, and another around 1500 BC (by Hatshepsut). Both involved long voyages down the Red Sea.^[13]

The biblical Book of Exodus tells the account of the Israelites' crossing of the sea, which the Hebrew text calls Yam Suph (Hebrew: יַם סוּף). Yam Suph was traditionally identified as the Red Sea. Rabbi Saadia Gaon (882‒942), in his Judeo-Arabic translation of the Pentateuch, identifies the crossing place of the Red Sea as Baḥar al-Qulzum, meaning the Gulf of Suez.^[14]

In the 6th century BC, Darius the Great, who was a prominent ruler of the Achaemenid Empire in Persia, undertook significant efforts to improve and extend navigation in the Red Sea. He sent reconnaissance missions to explore the Red Sea area and to identify its various navigational hazards, such as rocks and currents. This effort was significant, as it contributed to safer and more efficient navigation routes.^[15]

In addition to the maritime explorations, during the reign of Darius the Great, a canal was constructed linking the Nile River to the northern end of the Red Sea at Suez. This canal is sometimes referred to as the ancient Suez Canal. It played a pivotal role in improving trade and communication between the Nile Valley and the Red Sea, and beyond to the Indian Ocean. This canal was a predecessor to the modern Suez Canal, which was constructed in the 19th century and continues to be one of the world's most important waterways.^[16]

The construction of the canal during Darius's reign is evidenced by ancient records, including inscriptions. Darius commemorated the completion of the canal by creating stelae (stone monuments) with inscriptions in several languages, describing the construction and its benefits. The canal not only facilitated trade but also solidified Darius's control over Egypt and enhanced the Achaemenid Empire's economic and political power in the region.

In the late 4th century BC, Alexander the Great sent Greek naval expeditions down the Red Sea to the Indian Ocean. Greek navigators continued to explore and compile data on the Red Sea. Agatharchides collected information about the sea in the 2nd century BC. The Periplus of the Erythraean Sea ("Periplus of the Red Sea"), a Greek periplus written by an unknown author around the 1st century, contains a detailed description of the Red Sea's ports and sea routes.^[17] The Periplus also describes how Hippalus first discovered the direct route from the Red Sea to India.

The Red Sea was favored for Roman trade with India starting with the reign of Augustus, when the Roman Empire gained control over the Mediterranean, Egypt, and the northern Red Sea. The route had been used by previous states but grew in the volume of traffic under the Romans. From Indian ports goods from China were introduced to the Roman world. Contact between Rome and China depended on the Red Sea, but the route was broken by the Aksumite Empire around the 3rd century AD.^[18] From antiquity until the 20th-century, the Red Sea was also a trade route of the Red Sea slave trade from Africa to the Middle East.^[19]

Middle Ages and modern era

During the Middle Ages, the Red Sea was an important part of the spice trade route. In 1183, Raynald of Châtillon launched a raid down the Red Sea to attack the Muslim pilgrim convoys to Mecca.^[20] The possibility that Raynald's fleet might sack the holy cities of Mecca and Medina caused fury throughout the Muslim world.^[21] However, it appears that Raynald's target was the lightly armed Muslim pilgrim convoys, rather than the well guarded cities of Mecca and Medina, and the belief in the Muslim world that Raynald was seeking to sack the holy cities, due to the proximity of those cities to the areas that Raynald raided.^[22]

In 1513, trying to secure that channel to Portugal, Afonso de Albuquerque laid siege to Aden^[23] but was forced to retreat. They cruised the Red Sea inside the Bab al-Mandab, as the first fleet from Europe in modern times to have sailed these waters. Later in 1524 the city was delivered to Governor Heitor da Silveira as an agreement for protection from the Ottomans.^[24] In 1798, France ordered General Napoleon to invade Egypt and take control of the Red Sea. Although he failed in his mission, the engineer Jean-Baptiste Lepère, who took part in it, revitalised the plan for a canal which had been envisaged during the reign of the Pharaohs. Several canals were built in ancient times from the Nile to the Red Sea along or near the line of the present Sweet Water Canal, but none lasted for long. The Suez Canal was opened in November 1869. During the first half of the 20th-century, the Red Sea slave trade attracted substantional international condemnation.

After the Second World War, the Americans and Soviets exerted their influence whilst the volume of oil tanker traffic intensified. However, the Six-Day War culminated in the closure of the Suez Canal from 1967 to 1975. Today, in spite of patrols by the major maritime fleets in the waters of the Red Sea, the Suez Canal has never recovered its supremacy over the Cape route, which is believed to be less vulnerable to piracy.^{[citation needed]}

Iranian-backed Yemini Houthis have attacked Western ships, including warships, during the 2023-2024 Israel-Hamas war. One ship was hijacked and taken back to Yemen.^[25]

Salinity

The Red Sea is one of the saltiest bodies of water in the world, owing to high evaporation and low precipitation; no significant rivers or streams drain into the sea, and its southern connection to the Gulf of Aden, an arm of the Indian Ocean, is narrow.^[31] Its salinity ranges from between ~36 ‰ in the southern part and 41 ‰ in the northern part around the Gulf of Suez, with an average of 40 ‰. (Average salinity for the world's seawater is ~35 ‰ on the Practical Salinity Scale, or PSU; that translates to 3.5% of actual dissolved salts).^[32]

Tidal range

In general, tide ranges between 0.6 m (2.0 ft) in the north, near the mouth of the Gulf of Suez and 0.9 m (3.0 ft) in the south near the Gulf of Aden, but it fluctuates between 0.20 m (0.66 ft) and 0.30 m (0.98 ft) away from the nodal point. The central Red Sea (Jeddah area) is therefore almost tideless, and as such the annual water level changes are more significant. Because of the small tidal range the water during high tide inundates the coastal sabkhas as a thin sheet of water up to a few hundred metres rather than flooding the sabkhas through a network of channels. However, south of Jeddah in the Shoiaba area, the water from the lagoon may cover the adjoining sabkhas as far as 3 km (2 mi), whereas north of Jeddah in the Al-Kharrar area the sabkhas are covered by a thin sheet of water as far as 2 km (1.2 mi). The prevailing north and northeast winds influence the movement of water in the coastal inlets to the adjacent sabkhas, especially during storms. Winter mean sea level is 0.5 m (1.6 ft) higher than in summer. Tidal velocities passing through constrictions caused by reefs, sand bars and low islands commonly exceed 1–2 m/s (3–7 ft/s). Coral reefs in the Red Sea are near Egypt, Eritrea, Israel, Saudi Arabia, and Sudan.^[33]

Current

Detailed information regarding current data is lacking, partially because the currents are weak and both spatially and temporally variable. The variation of temporal and spatial currents is as low as 0.5 m (1.6 ft)^{[clarification needed]} and are governed all by wind. During the summer, northwesterly winds drive surface water south for about four months at a velocity of 15–20 cm/s (6–8 in/s), whereas in winter the flow is reversed resulting in the inflow of water from the Gulf of Aden into the Red Sea. The net value of the latter predominates, resulting in an overall drift to the north end of the Red Sea. Generally, the velocity of the tidal current is 50–60 cm/s (20–24 in/s) with a maximum of 1 m/s (3.3 ft/s) at the mouth of the al-Kharrar Lagoon. However, the range of the north-northeast current along the Saudi coast is 8–29 cm/s (3–11 in/s).^{[citation needed]}

Wind regime

The north part of the Red Sea is dominated by persistent north-west winds, with speeds ranging between 7 km/h (4.3 mph) and 12 km/h (7.5 mph). The rest of the Red Sea and the Gulf of Aden are subjected to regular and seasonally reversible winds. The wind regime is characterized by seasonal and regional variations in speed and direction with average speed generally increasing northward.^[34]

Wind is the driving force in the Red Sea to transport material as suspension or as bedload. Wind-induced currents play an important role in the Red Sea in resuspending bottom sediments and transferring materials from sites of dumping to sites of burial in quiescent environment of deposition. Wind-generated current measurement is therefore important in order to determine the sediment dispersal pattern and its role in the erosion and accretion of the coastal rock exposure and the submerged coral beds.^[35]

Oil and gas

Undiscovered oil reserves in the region have been estimated at 5,041 MMBO. Undiscovered gas reserves in the region have been estimated at 112,349 BCFG. Undiscovered natural gas reserves have been estimated at 3,077 MMBNGL.^[43] Most of these plays are controlled by the structure of the basin.^[44] Normal faults are common as the Red Sea occupies an active diverging margin. These targets are commonly found below the Salt deposits of the Middle Miocene.

Modern development is focused on the following fields. The Durwara 2 Field was discovered in 1963, while the Suakin 1 Field and the Bashayer 1A Field were discovered in 1976, on the Egyptian side of the Red Sea. The Barqan Field was discovered in 1969, and the Midyan Field in 1992, both within the Midyan Basin on the Saudi Arabian side of the Red Sea. The 20-m thick Middle Miocene Maqna Formation is an oil source rock in the basin. Oil seeps occur near the Farasan Islands, the Dahlak Archipelago, along the coast of Eritrea, and in the southeastern Red Sea along the coasts of Saudi Arabia and Yemen.^[45]

Mineral resources

This section does not cite any sources. (May 2022)

In terms of mineral resources the major constituents of the Red Sea sediments are as follows:

• Biogenic constituents:

Nanofossils, foraminifera, pteropods, siliceous fossils

• Volcanogenic constituents:

Tuffites, volcanic ash, montmorillonite, cristobalite, zeolites

• Terrigenous constituents:

Quartz, feldspars, rock fragments, mica, heavy minerals, clay minerals^[46]

• Authigenic minerals:

Sulfide minerals, aragonite, calcite, protodolomite, dolomite, quartz, chalcedony.

• Evaporite minerals:

Magnesite, gypsum, anhydrite, halite, polyhalite

• Brine precipitate:

Fe-montmorillonite, goethite, hematite, siderite, rhodochrosite, pyrite, sphalerite, anhydrite.

Tourism

The sea is known for its recreational diving sites, such as Ras Mohammed, SS Thistlegorm (shipwreck), Elphinstone Reef, The Brothers, Daedalus Reef, St. John's Reef, Rocky Island in Egypt^[55] and less known sites in Sudan such as Sanganeb, Abington, Angarosh and Shaab Rumi.

The Red Sea became a popular destination for diving after the expeditions of Hans Hass in the 1950s, and later by Jacques-Yves Cousteau.^[56] Popular tourist resorts include El Gouna, Hurghada, Safaga, Marsa Alam, on the west shore of the Red Sea, and Sharm-el-Sheikh, Dahab, and Taba on the Egyptian side of Sinaï, as well as Aqaba in Jordan and Eilat in Israel in an area known as the Red Sea Riviera.

The popular tourist beach of Sharm el-Sheikh was closed to all swimming in December 2010 due to several serious shark attacks, including a fatality. As of December 2010, scientists are investigating the attacks and have identified, but not verified, several possible causes including over-fishing which causes large sharks to hunt closer to shore, tourist boat operators who chum offshore for shark-photo opportunities, and reports of ships throwing dead livestock overboard. The sea's narrowness, significant depth, and sharp drop-offs, all combine to form a geography where large deep-water sharks can roam in hundreds of meters of water, yet be within a hundred meters of swimming areas. The Red Sea Project is building highest quality accommodation and a wide range of facilities on the coast line in Saudi Arabia. This will allow people to visit the coastline of the Red Sea by the end of 2022 but will be fully finished by 2030.^[57]

Tourism to the region has been threatened by occasional terrorist attacks, and by incidents related to food safety standards.^[58][59]

Security

The Red Sea is part of the sea roads between Europe, the Persian Gulf and East Asia, and as such has heavy shipping traffic. Government-related bodies with responsibility to police the Red Sea area include the Port Said Port Authority, Suez Canal Authority and Red Sea Ports Authority of Egypt, Jordan Maritime Authority, Israel Port Authority, Saudi Ports Authority and Sea Ports Corporation of Sudan.

Houthi rebels in Yemen have increased attacks on shipping vessels since mid-November 2023. The blocking of Israeli-linked ships was in response to Israel's war on Gaza.^[54] In January 2024, it was reported that Red Sea shipping volumes have dropped to 30% of normal levels due to Houthi intervention.^[60] In response, the US has announced a maritime coalition to defend shipping in the Red Sea for the Operation Prosperity Guardian.^[54] In January 2024, US and British forces undertook dozens of air and sea strikes on Houthi targets in Yemen. US President Joe Biden reportedly authorized strikes, despite not having congressional approval.^[61]