Final answer:
Hawaii is an example of an island that is part of the oceanic crust and has its peak above the ocean. The Hawaiian islands were formed by a mantle hot spot, generating a chain of volcanic islands with tall mountains.
Step-by-step explanation:
An example of an island that is part of the oceanic crust and has its peak above the ocean is Hawaii. The Hawaiian islands were formed by a mantle hot spot, which is an area far from plate boundaries where heat is rising from the interior of the Earth. The hot spot has generated a 3500-kilometer-long chain of volcanic islands, with the tallest Hawaiian volcanoes rising 9 kilometers above the ocean floor. One of these volcanic mountains, Mauna Kea, has become a renowned site for astronomy.