How are the Atlantic and the pacific ocean alike?

The Pacific Ocean is the largest ocean in the world at 155,557,000 sq km. Its deepest point is the Mariana Trench (Challenger Deep) at 11,033 metres. The Atlantic Ocean is the second largest ocean in the world at 76,762,000 sq km. It is also the second deepest at the Puerto Rico Trench (Milwaukee Deep) at 8,648 metres.