Scientists reveal why pressure builds inside 'super volcanoes' - the eruptions every 100,000 years that can bring Ice Ages

Reseachers have finally discovered the causes for volcanic 'super-eruptions'  - one of the most catastrophic natural events on Earth.

The violent explosions, which occur about every 100,000 years, are now thought to be caused by a combination of temperature and the shape of the magma chamber inside certain volcanoes.

Scientists at Oregon State University presented the finding at the annual meeting of the Geological Society of America in Minneapolis.

Catastrophic: The Huckleberry Ridge eruption of present-day Yellowstone Park about two million years ago was more than 2,000 times larger than the 1980 eruption of Mount St. Helens in Washington

Patricia Gregg, lead author on the modeling study, said the creation of a 'halo' of rock around the magma chamber allows the pressure to build over tens of thousands of years, resulting in extensive uplifting in the roof above the magma chamber.

Eventually, faults from above trigger a collapse- and then eruption.

She said: 'You can compare it to cracks forming on the top of baking bread as it expands.'

'As the magma chamber pressurises at depth, cracks form at the surface to accommodate the doming and expansion.'

She added: 'Eventually, the cracks grow in size and propagate downward toward the magma chamber.

Super eruption: The Yellowstone eruption is one of the largest super-volcano events in history and it has happened several times

'In the case of very large volcanoes, when the cracks penetrate deep enough, they can rupture the magma chamber wall and trigger roof collapse and eruption.'

The eruption of super-volcanoes dwarfs the eruptions of recent volcanoes and can trigger planetary climate change by inducing Ice Ages and other impacts.

One such event was the Huckleberry Ridge eruption of present-day Yellowstone Park about two million years ago, which was more than 2,000 times larger than the 1980 eruption of Mount St. Helens in Washington.

'Short of a meteor impact, these super-eruptions are the worst environmental hazards our planet can face,' Gregg said.

'Huge amounts of material are expelled, devastating the environment and creating a gas cloud that covers the globe for years.'

Read more: http://www.dailymail.co.uk/sciencetech/article-2048432/Secret-volcanic-super-eruptions-happen-100k-years-unlocked.html