Which phenomenon primarily determines the arc shape of volcanic island chains formed at subduction zones?

💡 Explanation

When a denser oceanic plate subducts, the descending lithospheric slab curves due to Earth's curvature and resistance in the mantle, causing dehydration melting at relatively consistent depths, forming volcanoes in an arc shape. Therefore the curvature causes the outcome, rather than plume distribution, sediment deposition, or wind patterns which are not directly linked to the arc shape.

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