Which mechanism causes an island arc to form instead of continental volcanism when two oceanic plates converge?

💡 Explanation

When two oceanic plates converge, slab rollback occurs because the older, denser plate subducts steeply causing increased magma flux and volcanism away from the trench, generating an island arc. Therefore, an island arc results, rather than continental volcanism, requiring a continent-ocean boundary.

• Which consequence results when longshore drift encounters a deepwater submarine canyon?
• Which outcome occurs when seasonal meltwater floods a glacial valley?
• Which morphology change in barrier islands results when wave refraction focuses energy on adjacent headlands?
• Which primary effect follows the artificial lengthening or heightening of river levees to manage flood risk?
• Which effect does Coriolis force have upon air as it moves from hadley cell descent towards equatorial latitudes?
• Which flow regime results when glacial meltwater discharge increases within a fjord system?