The missing word here is Asthenosphere.
The convection in the asthenosphere directly propels the tectonic plates of the earth.
Did you know that the asthenosphere is thought to remain malleable because of heat from deep within the Earth? It is thought to be lubricating the earth's tectonic plates' undersides and enabling movement.
The older, denser portions of the lithosphere that are dragged downward in subduction zones are stored in the asthenosphere, according to the theory of plate tectonics.
The lithosphere above is stressed by convection currents, and the cracking that frequently results manifests as earthquakes.
Magma is forced upward through volcanic vents and spreading centers by convection currents produced within the asthenosphere, which also results in the formation of new crust.
Learn why properties of the asthenosphere are important: https://brainly.com/question/11484043
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