Continental margin
Topic: Oceans: Hydrological Cycle, Relief of the Ocean Floor, Temperature and Salinity · NCERT: Class 11, Ch 4 "Distribution of Oceans and Continents"; Class 11, Ch 12 "Water (Oceans)"
Meaning
The continental margin is the zone between the shore of a continent and the deep ocean floor. It has three parts. The first is the gently sloping continental shelf. The second is the steeper continental slope. The third is the continental rise, a wedge of sediment (sand, mud and silt) piled at the foot of the slope. Beyond the margin lies the deep abyssal plain. Margins matter because they hold rich fisheries and oil and gas deposits.
Example
Off India's west coast, the continental margin includes a wide shelf in the Arabian Sea. The Bombay High oilfield lies on this shelf.
Don't confuse with
- Continental shelf: this is only the shallow first part of the margin. The margin also includes the slope and the rise.
Related concepts
- Relief of the ocean floor
- Continental shelf
- Continental slope
- Abyssal plain
- Oceanic trench
- Mariana Trench
- Puerto Rico Trench
- Sunda Trench