The extension of the landmass into the sea is shown as the

Solution (By Examveda Team)

The extension of the landmass into the sea is shown as the Continental shelf. Continental shelves were formed in between glacial periods as the ocean flowed over the continents forming shallow areas along the coasts. About 18,000 years ago, during the height of the Pleistocene ice ages, much of what is now a continental shelf was actually above water.