Question

Can someone halp meh with this about revising questions on the ocean thanks.

BTW u don't have to do all of them but at least do 1 ok thanks
*this was science but there isn't any science so i just put art lol

Answer 1

What is a volcanic island - Volcanic islands occur in ocean basins (such as the Hawaiian Islands) or on or near ocean ridges (e.g., St. Paul Rocks and Ascension Island in the Atlantic Ocean) (Fig. 1.3). They are large volcanoes erupted on the seafloor whose tops have emerged above sea level. Volcanic islands and seamounts (submerged volcanoes) range in tectonic stability from intermediate or unstable in areas where volcanism is active (like Hawaii and Reunion), to stable in areas of extinct volcanism (such as Easter Island). Volcanic islands range in size from < 1 to about 104 km2. Guyots are flat-topped seamounts produced by erosion at sea level followed by submersion, probably due to sinking of the seafloor. Coral reefs grow on some guyots as they sink, producing atolls. Some of the large volcanic islands may have developed over mantle plumes, which are the magma sources.

Answer 2

A high island or volcanic island is an island of volcanic origins. The Hawaiian Islands are the tops of volcanic mountains rising above the ocean floor. These volcanoes formed over a localized hot spot of magma generation. As the older volcanoes formed great shields and died, the movement of the ocean floor and crust shifted them to the northwest.

A higher percentage of sand shores are found on the older islands. Beaches on the Hawaiian Islands are smaller than those on the continental shores because of the young age of the islands, the absence of large rivers to supply sediment, and the shape and exposure of the island beaches to the wave systems that affect the islands.

The sand on the beaches is also different in that it is primarily calcareous and of biologic origin. The calcareous sand originates as shells and test of animals or algae that live on the fringing reefs or shallow waters adjacent to the islands. Two exceptions are some beaches near stream mouths that are detritus basalt sand, and a few beaches on the island of Hawaii are black volcanic glass sand generated by the steam explosions that occur when hot lava flows into the ocean.