The Red Sea: Indian Ocean’s Northern Arm Between Africa and Arabia

The Red Sea is a seawater inlet of the Indian Ocean lying between Africa (Egypt, Sudan, Eritrea, Djibouti) and the Arabian Peninsula (Saudi Arabia, Yemen).

Key Facts

• Length: 2,250 km (1,400 mi)
• Max width: 355 km (220 mi)
• Max depth: 2,211 m (7,254 ft) in central axial trough
• Surface area: 438,000 km²
• Salinity: 4.1% (world’s saltiest open sea—high evaporation, no rivers, limited connection)

Connections

• South: Bab el-Mandeb Strait → Gulf of Aden → Indian Ocean.
• North: Suez Canal (1869) → Mediterranean Sea → Atlantic.
• Gulfs: Gulf of Suez (west), Gulf of Aqaba (east).

Why "Red"?

Possibly from Trichodesmium erythraeum blooms (red-brown cyanobacteria), or "Red" = "South" in some ancient color-direction systems (like Black Sea = North).

Significance

Critical shipping lane (12% global trade). Unique coral reefs (high heat tolerance). Rift valley geology—spreading center, hydrothermal vents, mineral deposits. Border disputes, piracy history, desalination hub.