Clarifying Confusing Concepts: Strait and Isthmus: A Strait is a Narrow Body of Water

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• A strait is a narrow body of water that connects two larger bodies of water. It may be formed by a fracture in an isthmus, a narrow body of land that connects two bodies of water. Tectonic shifts can lead to straits like this.
• An isthmus is a narrow strip of land that connects two larger landmasses and separates two bodies of water. This type of isthmus is called a tombolo, and is formed as waves and tides slowly build up a sand bar to create a permanent link between a coastal island (called a tied island) and the mainland.

• One strait that was formed by tectonic activity is the Strait of Gibraltar, the only link between the Mediterranean Sea and the Atlantic Ocean.
• The Strait of Gibraltar is narrowing and closing, as the African plate slides north. Soon, Strait of Gibraltar will be the Isthmus of Gibraltar, and the Mediterranean will be a large, salty, inland sea. If fractures in an isthmus are created by human activity, the straits are usually called canals.
• Suez Canal was constructed in 1869 as a waterway between the Mediterranean Sea and the Red Sea
• A strait can also be formed by a body of water overflowing land that has subsided or has been eroded. The Bosporus, which links the Black Sea and the Marmara Sea, was formed this way – separates Europe from Asia
• The Isthmus of Panama in Panama links the continents of North and South America
• The Isthmus of Suez in eastern Egypt connects the continents of Africa and Asia, and separates the Mediterranean and Red Seas.

• The city of Seattle, Washington, is located on an isthmus between the Puget Sound (part of the Pacific Ocean) and Lake Washington.
• Mount Maunganui, New Zealand, is a tombolo town located on a sandbar connecting the volcanic island of Mauao to the mainland.

✍ Manishika