One of the key reasons for Federation was to achieve a united defence force which could better protect Australia. Around the 1880s, the Australian colonies had become increasingly concerned over the close proximity of foreign powers.
Split and merge into it. Answered by The Community. Making the world better, one answer at a time. Dissolved gases trapped in the magma provides the force that causes magma to erupt to the surface. Magma is molten material before it reaches the surface and is lava.
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.here is a convection current caused by radioactivity in the inner core which causes the plates to move. Therefore the â¦ constructive plates move apart which means magma can rise up. It'll then solidify and this is what makes volcanoes.