The area where one plate sinks into the asthenosphere underneath another plate is known as .

Explanation: subduction zone

A subduction zone is the biggest crash scene on Earth. These boundaries mark the collision between two of the planet's tectonic plates. The plates are pieces of crust that slowly move across the planet's surface over millions of years.

Where two tectonic plates meet at a subduction zone, one bends and slides underneath the other, curving down into the mantle. (The mantle is the hotter layer under the crust.)  

Heat from deep within Earth is thought to keep the asthenosphere malleable, lubricating the undersides of Earth’s tectonic plates and allowing them to move

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