What is another word for upper mantle?
Pronunciation: [ˌʌpə mˈantə͡l] (IPA) 
The upper mantle is a layer of the Earth's interior lying above the lower mantle and beneath the crust. This central layer of the Earth's structure has various synonyms, such as the asthenosphere, which comprises the soft, deformable layer found below the lithosphere. Another synonym for the upper mantle is the transition zone, a layer between the upper and lower mantle known as a zone of seismic discontinuity and a region of significant pressure and temperature changes. The mantle proper is another synonym that refers to the whole mantle region; however, its upper part is usually referred to as the upper mantle and stands as the layer continuously in motion, driving the tectonic plates on which the Earth's continents rest.
