The continental shelf is the extended margin of each continent occupied byrelatively shallow seas and gulfs. It is the shallowest part of the ocean showing anaverage gradient of 1° or even less.The width of the continental shelves vary from one ocean to another. The average widthof continental shelves is about 80 km.
Significance of Continental shelf:
- Massive sedimentary deposits received over a long time by the continentshelves, become the source of fossil fuels.
- Their shallowness enables sunlight to penetrate through the water, which encouragesthe growth of plants and organism ? now rich in plankton ? fishes thrive on them –so continental shelves are richest fishing grounds.Eg. Grand Banks of Newfoundland, The North sea and the sunda shelf.
- Their limited depth and gentle slope keep out cold under-currents and increase the
height of tide. This sometimes hinders shipping and other marine activities since ships
can only enter and leave port on the tide.