You are watching: Volcanic island arcs are associated with which type of plate boundary?
Stromboli Volcano results as result of convergence that the Eurasian through the afri PlateImage Credit: MBG
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Taal Volcano (Phillipines) results because of convergence the the Phillipines and Eurasian platesImage Credit: MBG
b) Convergent bowl boundaries and subduction
At dispersing centers, new lithosphere is continually gift generated. However, due to the fact that the full area of earth remains constant, lithosphere must additionally be destroyed. The zones of bowl convergence room these web page of this destruction. At these zones, the denser bowl sinks below the much less denser bowl (at a velocity the a few cm every year), i m sorry itself continues to be floating over the asthenosphere. This altoalsimce.orgdynamic process, arising along deep-sea trenches, is referred to as subduction. The huge forces i m sorry occur during this procedure produce great earthquakes. Product scraped off the descending key is included into the nearby mountains as microplates or accreted terranes. When the subducting oceanic plate reaches a depth of about 100 kilometers, partial melt of the water-rich oceanic crust and also some of the overlying mantle takes place. The newly developed magma produced in this path is less dense than the surrounding mantle rocks and, consequently, when sufficient quantities have actually gathered, will slowly rise. Most of the rising magma will certainly be emplaced in the overlying continental crust, wherein it will certainly cool and also crystallize in ~ a depth of several kilometers. The continuing to be magma will at some point migrate to the surface where it can offer rise come numerous and also occasionally explosive volcanic eruptions along a volcanic arc.
A volcanic arc is usually formed by a chain the volcanoes. That parallels the trench approximately 100 kilometres inland. As soon as two oceanic plates collide versus each other, the older and also therefore heavier of the 2 subducts in ~ the other, initiating volcanic activity in a manner comparable to the which occurs at one oceanic-continental convergent key boundary and forming a volcano island arc.
Where 2 continents approach each other, the intervening sea-floor is subducted, causing arc-type volcanism. Through collision that the two continental plates, subduction ceases because neither the the continent plates will certainly subduct beneath each other. The result is a collision in between two continental blocks. During this collision, the continent crust is folded, stacked and thickened , and also generally shortened. A large zone of intense deformation establishes at this boundary. This boundary is significant by a mountain selection which often shows up as a magmatic belt follow me a suture. The whole procedure of mountain development in which continental crust may thicken to as much as 70 kilometres (e.g. Himalayas) is called orogenesis.