When the Earth Explodes

To understand a super volcano you must know how they evolve in the context of the dynamic Earth, which is a body in transition. Super volcanoes usually form where the crust piles up at plate tectonic boundaries and there is subduction of one plate under another. The piling up is what creates mountain chains that are doted with volcanic vents. Although generally true, there are some notable exceptions, such as in Yellowstone Park in the central United States. As high as the mountains are, there is a "root" that extends down into the mantle just under the lithosphere. At the active regions of the building mountain chains there is a lot of heat build up and the formation of volcanoes and super volcanoes. A super volcano is basically a super-sized version of an average volcano, but is usually considered to be of the type that produces ash as opposed to lava. If the Hawaiian volcanoes were of the ash type instead of the lave producing variety, they would likely be classified as super volcanoes due to their shear size.

The subduction of one plate under another causes the lithosphere to build up regionally and it also generates earthquake activity and local crustal heating. Over the ages, the heat builds up as much of the lithosphere is a poor conductor of heat. Magma chambers are built up in many areas such as around the Pacific Ring of Fire. Once the heat and pressure is sufficient and moves up close enough to the surface, there is a cataclysmic explosion of refractory material that is pulverized into dust, small pumice stones, lava bombs and the like. It is the dust that actually poses the greatest threat, as this is lofted high into the stratosphere to be carried around the globe in the jet stream. The dust, if sufficient in quantity, blocks out sunlight from reaching the surface of the Earth and the result is a volcanic winter of many years. This causes crop failure and the subsequent starvation for all animal species higher on the food pyramid.

On Earth there are quasi-periodic explosions which originate from deep within. In keeping with other phenomena most are small a few are huge. It is the huge explosions that are of concern here. These leave their imprints through ash and sulfur. Unlike impacts, there is no iridium, thus allowing us to distinguish volcanic catastrophes from impact events. From the very beginning after the major impact accretion was completed some 3.85 billion years ago, the Earth has experienced volcanic

• 1
• 2
• 3
• 4
• 5
• 6
• next page >>

---

Add your voice

Know something about What is a super volcano??
We want to hear your view. Write now!