Which phenomenon causes mantle upwelling beneath the overriding plate where an oceanic plate subducts at an increasing angle?

💡 Explanation

When an oceanic slab subducts at an increasing angle, slab rollback occurs because the slab pulls itself downward, inducing suction in the asthenosphere and causing mantle upwelling. Therefore asthenosphere suction results, rather than crustal loading, hydrothermal circulation, or accretion which involve different crustal processes.

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