sustain (sustains 3rd person present) (sustaining present participle) (sustained past tense & past participle) 1 verb If you sustain something, you continue it or maintain it for a period of time. But he has sustained his fierce social conscience from young adulthood through old age... V n. ...a period of sustained economic growth throughout 1995.
If oceanic and continental crust collides the denser one which is the oceanic crust will be subducted, go underneath, the continental crust. The high heat of the mantle causes the oceanic crust to melt into magma. If the crust gets cracked this allows magma to rise and come out of the crust as lava which will form Volcanoes. When two continental crusts collide, the crust is forced to go upwards which forms mountains.
Magma rises from the asthenosphere to the surface of the Earth.  After it reaches temperature upward to 1000 degrees Fahrenheit, the  magma starts to rise. Gases also aid in â¦ pushing the magma toward  the surface, along with the tremendous pressure from the depth at  which it originates. Answered.