volcanoes

volcano is an opening in a planet's surface or crust which allows hot magma, ash and gases to escape from  below the surface. 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 such as in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. (voomy voomy sh sh eh eh)

Island arcs

Ok an island arc is a curved chain of volcanic islands.Island arcs are usually found in the Pacific where they ring the ocean on both sides; the Aleutian Islands off Alaska are an example.

a island arc

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This is the Aleutian Islands in Alaska this an exaple of an  island arc

examples of island arcs

Examples




Island arc Country Trench Basin or marginal sea Plate Subducting plate

Aleutian Islands United States Aleutian Trench Bering Sea North American Plate Pacific Plate


Kuril Islands Russia Kuril-Kamchatka Trench Sea of Okhotsk North American Plate Pacific Plate

Japanese Archipelago Japan Japan Trench、Nankai Trough Sea of Japan North American Plate, Eurasian Plate Pacific Plate, Philippine Sea Plate

Ryukyu Islands Japan Ryukyu Trench East China Sea (Okinawa Trough) Eurasian Plate Philippine Sea Plate

Philippine Islands Philippines Philippine Trench South China Sea, Celebes Sea Eurasian Plate Philippine Sea Plate

Andaman and Nicobar Islands India Northern Java Trench Andaman Sea Eurasian Plate Indo-Australian Plate

Izu Islands and Bonin Islands (Ogasawara Islands) Japan Izu-Ogasawara Trench Philippine Sea Plate Pacific Plate

 Mariana Islands United States Mariana Trench Philippine Sea Plate Pacific Plate

Bismarck Archipelago Papua New Guinea New Britain Trench Pacific Plate Australian Plate

Solomon Islands (archipelago) Solomon Islands San Cristobal Trench Pacific Plate Australian Plate


New Hebrides Vanuatu New Hebrides Trench Pacific Plate Australian Plate

 Tonga islands Tonga Tonga Trench Australian Plate Pacific Plate

Antilles Puerto Rico Trench Caribbean Sea Caribbean Plate North American Plate, South American Plate

South Sandwich Islands United Kingdom South Sandwich Trench Scotia Sea Scotia Plate South American Plate

 Egean, or Hellenic arc Greece Eastern Mediterranean Trench Aegean Sea Aegean Sea Plate or Hellenic Plate African Plate

more island arcs

An island arc is a curving series of volcanic islands that are created through the collision of tectonic plates in an ocean.The particular type plate boundary that yields island arcs is called a subduction zone. In a subduction zone, one lithospheric plate is forced downward under an upper plate. Continual tectonic movement pushes the lower plate deeper until it reaches a depth where temperatures are sufficient to begin to melt the subducted plate and form magmas. These magmas then rise through fractures and melt their way through the overlying crust to be extruded in the form of volcanoes. The volcanoes are generally andesitic in composition. If the overriding plate is oceanic, then volcanoes are extruded underwater and may eventually rise high enough to become islands. The volcanoes form in a line because the angle and rate of subduction, and hence the distance to the depth where melting occurs is consistent. Because the surface of Earth is curved, the line of volcanoes forms in an arcuate pattern in much the same manner as an arc is produced when a planar surface intersects a sphere.teehee.bye