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Islands
Islands are landforms that contribute to geography. They can be resort islands, man-made islands or naturally-formed islands.
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Africa is known for a variety of landforms, including the African Great Rift Valley, the Sahara Desert, the Atlas Mountains, and the Congo Basin. These landforms play a crucial role in shaping the diverse ecosystems found across the continent, from deserts to rainforests. Many of Africa's landforms are a result of tectonic activity and erosion processes over millions of years.
How do volcanoes create islands?
A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by "divergent tectonic plates" pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by "convergent tectonic plates" coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.
Volcanoes can be caused by "mantle plumes". These so-called "hotspots" , for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.
Plate tectonics and hotspots
Map showing the divergent plate boundaries (OSR Oceanic Spreading Ridges) and recent sub aerial volcanoes.
Divergent plate boundaries
At the mid-oceanic ridges, two tectonic plates diverge from one another. New oceanic crust is being formed by hot molten rock slowly cooling and solidifying. The crust is very thin at mid-oceanic ridges due to the pull of the tectonic plates. The release of pressure due to the thinning of the crust leads to adiabatic expansion, and the partial melting of the mantle causing volcanism and creating new oceanic crust. Most divergent plate boundaries are at the bottom of the oceans, therefore most volcanic activity is submarine, forming new seafloor. Black smokers or deep sea vents are an example of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, Iceland.
Convergent plate boundaries
Subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the oceanic plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. Water released from the subducting plate lowers the melting temperature of the overlying mantle wedge, creating magma. This magma tends to be very viscous due to its high silica content, so often does not reach the surface and cools at depth. When it does reach the surface, a volcano is formed. Typical examples for this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire.
Hotspots
Hotspots are not usually located on the ridges of tectonic plates, but above mantle plumes, where the convection of the Earth's mantle creates a column of hot material that rises until it reaches the crust, which tends to be thinner than in other areas of the Earth. The temperature of the plume causes the crust to melt and form pipes, which can vent magma. Because the tectonic plates move whereas the mantle plume remains in the same place, each volcano becomes dormant after a while and a new volcano is then formed as the plate shifts over the hotspot. The Hawaiian Islands are thought to be formed in such a manner, as well as the Snake River Plain, with the Yellowstone Caldera being the part of the North American plate currently above the hotspot.
Volcanic features
The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit. This describes just one of many types of volcano, and the features of volcanoes are much more complicated. The structure and behavior of volcanoes depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic material (lava, which is what magma is called once it has escaped to the surface, and ash) and gases (mainly steam and magmatic gases) can be located anywhere on the landform. Many of these vents give rise to smaller cones such as Puʻu ʻŌʻŠon a flank of Hawaii's Kīlauea.
Other types of volcano include cryovolcanoes (or ice volcanoes), particularly on some moons of Jupiter, Saturn and Neptune; and mud volcanoes, which are formations often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano.
What landforms are found in Africa?
Africa is home to a diverse range of landforms, including mountains such as the Atlas Mountains and Mount Kilimanjaro, deserts like the Sahara and Kalahari, plateaus such as the Ethiopian Highlands, rivers like the Nile and Congo, and lakes including Lake Victoria and Lake Tanganyika. The continent also features savannas, grasslands, and tropical rainforests.
What process forms island arcs?
Island arcs are formed from the subduction and melting of oceanic crust as it descends into the mantle underneath a less dense oceanic crust at a convergent plate boundary. The subduction results in the creation of undersea volcanoes which then rise above sea level. The resulting volcanoes create a string of islands called an island arc. The curve of an island arc echoes the curve of its deep-ocean trench.
What islands are near Ft Lauderdale Florida?
Some islands near Fort Lauderdale, Florida are Elliott Key, Key Biscayne, and Boca Chita Key in Biscayne National Park. Additionally, the Bahamas are relatively close to Fort Lauderdale, with popular destinations like the Grand Bahama and Bimini islands just a short boat or plane ride away.
What forms the islands of Hawaii?
The islands of Hawaii were formed from volcanic activity over millions of years. The islands are the result of magma rising from hot spots in the Earth's mantle, creating shield volcanoes that eventually emerged from the ocean. The movement of the Pacific tectonic plate over these hot spots has led to the formation of the Hawaiian island chain.
The cohesive forces between liquid molecules, such as hydrogen bonding or van der Waals forces, hold liquids together. These forces create a surface tension that allows liquids to maintain a compact shape and form droplets.
What is the estimate of the number of islands in the world?
Even I am looking for the same answer. Sorry mate I am also anxious to know the answer of it, if someone get it and post it.. please....
I have been working on this question for quite some time. Have not yet found the precise answers, but here are some fairly accurate lists of the countries with the most islands, which will help (I have not verified all of these personally but I believe they are good estimates) : Indonesia has around 21,000 if you include all the islets; Norway, 117,000; Finland 179,584; Sweden, 221,800; Canada, at least 100,000 but perhaps much larger; South Korea, 15,000; Philippines, 7100; island countries in the Pacific Ocean 20,000 to 30,000; Chile, at least 6000; and numerous countries have well over a thousand each, including USA, Japan, Maldives, Great Britain, Greece, Russia, China, and several others. A few of the countries which have between 500 and a thousand include Denmark, Estonia, and Bahamas. This suggests a world total which is at least 750,000, but I would not be surprised if the real total is between 1 and 2 million, if one includes inland (lake) islands as well as protruding rocks and islets.What plate are the Aleution Islands on?
The Aleutian Islands are located on the boundary between the Pacific Plate and the North American Plate, with the Pacific Plate subducting beneath the North American Plate. This tectonic boundary is part of the larger Ring of Fire region characterized by tectonic activity including earthquakes and volcanic eruptions.
What is the largest island in the world called?
The largest island in the world is called Greenland. It is an autonomous territory within the Kingdom of Denmark, located in the Arctic region.
Is Long Island the largest island in the US?
No, but it is the largest island in the continental USA No, but it is the largest island in the continental USA
What hawaiian island is know as The big one?
The Big Island of Hawaii is the island referred to as "The Big Island" due to its larger size compared to the other Hawaiian islands. It is also known as Hawaii Island to avoid confusion with the name of the entire state.
How do volcanoes and volcanic islands form?
Volcanoes happen at 2 out of 4 plate boundaries: Constructive plate boundaries and destructive plate boundaries.
In a constructive plate boundary, the plates move apart, causing earthquakes, and letting magma pass through, creating volcanoes.
In a destructive plate boundary, the plates push together. This creates a subduction zone. The rock jolts and grinds its way down causing earthquakes and volcanoes.
Importance of mountain and other landforms to mankind?
Mountain and landforms are important to mankind for various reasons. They provide important habitats for diverse plant and animal species. They also play a crucial role in regulating the climate, water cycle, and soil erosion. Additionally, landforms offer opportunities for recreation, tourism, and cultural significance.
Sandy island that forms near the coast?
A sandbar is a temporary, underwater or exposed ridge of sand, gravel, or shell material that is built up by currents in a river or by waves on a beach. It typically forms near the coast and can disappear or change shape depending on tides and currents.
What is the world's second largest island?
The second largest island in the world is New Guinea. Greenland (not Australia) is the largest island.
What is the largest island continent?
asia
IT'S NOT ASIA!!! Read the question!!!First of all, by definition, an island must be smaller than a continent. Therefore, there would be no such thing as an "island continent". But if we're not splitting hairs, then the largest "island continent" would be Antarctica. Unfortunately, that's only if it's covered with ice. So if we're measuring its area without the ice, the answer to the question would be Australia.What is the Florida land mass?
Florida is a peninsula located in the southeastern United States, bordered by the Gulf of Mexico to the west and the Atlantic Ocean to the east. It is known for its warm climate, sandy beaches, and diverse ecosystems, including the Everglades.
Is the state of Alaska an island?
The peninsula located in the state of Alaska is named the Alaskan Peninsula. It extends from the mainland of the state to the Aleutian Islands, and separates the Pacific Ocean and Bristol Bay.
What are the physical features of the Guano Islands?
There is no actual "Guano Island". There is a Guano Island Act, which is a federal legislation passed by the US Congress on 18 August 1856. It enables US citizens to take possession of islands containing guano deposits. Guano is the droppings of bats, seabirds, and seals. It is a highly prized fertilizer.
What island group found northeast of Australia has a capital of Honiara?
The island group northeast of Australia with a capital of Honiara is the Solomon Islands. The country consists of a group of islands in the South Pacific Ocean.
The central idea of biological evolution is that all life on Earth shares a common ancestor. Over a large number of years, evolution produces diversity in forms of life due to gene flow, mutations, migration, genetic drift, and natural selection. Some things can be explained, for example, in geographical isolation. Over time a species which can not interbreed because of mountains, becomes less alike and can no longer interbreed to form fertile offspring.
Should NC help homeowners in the barrier islands that are vulnerable to storms rebuild after one?
Yes, it is important for North Carolina to assist homeowners in barrier islands vulnerable to storms to rebuild after one, as they are at high risk of devastation. Providing financial assistance, infrastructure improvements, and guidance on resilient building practices can help mitigate future damage and protect the safety and livelihoods of residents in these areas.
How did the Hawaiian Islands form?
Volcanoes - It is called a hot spot and as the earths crust moves over the spot, volcanoes form and in this case, created the chain of islands.
They formed from a hot spot in earths crust
The Hawiian Islands are the tops of huge undersea volcanoes.
The way the islands have formed, although far away from any fault, the area is a volcanic hot-spot. Back a couple million years, the crust beneath was thinning and rising. A series of undersea volcanic eruptions force volcanic material upwards, making the islands. The thinning of the crust, literally, moves southward to make other islands.
It has to do wih tectonic plates
