A new study suggests that the common belief that the Earth's rigid tectonic plates stay strong when they slide under another plate, known as subduction, may not be universal.
Typically during subduction, plates slide down at a constant rate into the warmer, less-dense mantle at a fairly steep angle. However, in a process called flat-slab subduction, the lower plate moves almost horizontally underneath the upper plate.
The research, by Southampton University found that the Earth's largest flat slab, located beneath Peru, where the oceanic Nazca Plate is being subducted under the continental South American Plate, may be relatively weak and deforms easily.
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