GEOLOGY

Detailed explanation-1: -As gas bubbles accumulate, the upward pressure increases, forcing cracks in the rocks to widen, often in the direction of Earth’s surface. For magma to erupt from a volcano, this upward pressure must exceed the downward pressure that is exerted by the eight-kilometer (five mile) thick load of rock overhead.

Detailed explanation-2: -Answer: Volcanoes are formed by eruptions of lava and ash when magma rises through cracks or weak-spots in the Earth’s crust. A build up of pressure in the earth is released, by things such as a plate movement which forces molten rock to exploded into the air causing a volcanic eruption.

Detailed explanation-3: -The melted rock, or magma, is lighter than the surrounding rock and rises up. This magma collects in magma chambers, but it is still miles below the surface. When enough magma builds up in the magma chamber, it forces its way up to the surface and erupts, often causing volcanic eruptions.

Detailed explanation-4: -Volcanoes erupt because of density and pressure. The lower density of the magma relative to the surrounding rocks causes it to rise (like air bubbles in syrup). It will rise to the surface or to a depth that is determined by the density of the magma and the weight of the rocks above it.

Detailed explanation-5: -Gases can be both dissolved in the magma chamber and also emitted from volcanoes at the surface. It’s the dissolved gases cause volcanoes to erupt. A magma chamber contains high pressure and dissolved gases.