Islands
Published on Nov 18, 2015
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PRESENTATION OUTLINE
There are over 100,000 islands on earth. Many are tropical and many are covered in ice. The number of islands on earth is constantly changing due to the rise and fall of sea levels. When the sea levels are high, many small islands disappear. There are several different ways for islands to form.
CREATION OF ISLANDS
The creation of an island can happen many different ways. There are volcanic islands that are created from undersea volcanoes erupting and the lava builds an island as it continues toflow out. There are islands that are created from the tectonic plates as they shift. These types of islands are called rift islands. If you want your own island there are special machines that force sand to the bottom of the ocean and eventually with enough build up creates an island.
Photo by NASA's Marshall Space Flight Center
Delicate Ecosystems
Islands have their own special ecosystems. The balance has to be maintained otherwise plant and animal life become endanger. Over 70% of the world’s extinctions happen on islands. This is due to human habitation, or introduction of species that are not natural inhabitants to the island. Many times when an ecosystem is upset it is impossible for it to be set back to balance.
Large Islands
Greenland is considered to be the largest island in the world. However, Australia is three times bigger than Greenland. Australia is considered to be an island continent, thus not making it an island. The smallest island really cannot be determined, reason being there are no set guidelines to determine what makes an island.
Interesting Island Facts...
Did you know that 1 in 6 people are an islander? The most populated island in the world is Java, Indonesia with a population over 130 million people. The least populated island is Pitcairn Island in the Pacific Ocean. There are a total of about 48 people. All 48 belong to just 4 families.
Continental islands, which occur due to flooding and erosion of land on the edge of a large continent. Greenland is an example of a continental island. As well as Madagascar.
Smaller islands are called cays, keys, or islets. Normally the smaller islands are islands made up of coral, sand, or broke off a major continent. Such as the Florida Keys.
Volcanic islands, which are formed when volcanoes deep in the ocean rise above the water's surface. An example of volcanic islands are the Hawaiiian Islands. The islands of Hawaii are all made up of volcaneos and dried up lava. Some of the volcanoes in Hawaii are very active.
Photo by Emlyn Stokes
Coral Islands or Atoll Islands are islands made up off coral from the Reefs. The coral grows up above the sea and dirt and sand pile the coral and make an island. An example of theses island are the islands of Tahiti, such as Bora Bora. As well as the Cayman Islands.
Photo by FrankGuido
