Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Supervolcanoes: Not a threat for 2012

16.11.2011
The geological record holds clues that throughout Earth's 4.5-billion-year lifetime massive supervolcanoes, far larger than Mount St. Helens or Mount Pinatubo, have erupted. However, despite the claims of those who fear 2012, there's no evidence that such a supereruption is imminent.

What exactly is a "supervolcano" or a "supereruption?" Both terms are fairly new and favored by the media more than scientists, but geologists have begun to use them in recent years to refer to explosive volcanic eruptions that eject about ten thousand times the quantity of magma and ash that Mount St. Helens, one of the most explosive eruptions in recent years, expelled.


In Yellowstone, the rim of a supervolcano caldera is visible in the distance. Credit: National Park Service

It's hard to comprehend an eruption of that scope, but Earth's surface has preserved distinctive clues of many massive supereruptions. Expansive layers of ash blanket large portions of many continents. And huge hollowed-out calderas – craters that can be as big as 60 miles (100 km) across left when a volcano collapses after emptying its entire magma chamber at once – serve as visceral reminders of past supereruptions in Indonesia, New Zealand, the United States, and Chile.

The eruption of these prehistoric supervolcanoes has affected massive areas. The magma flow of Mount Toba in Sumutra, which erupted some 74,000 years ago in what was likely the largest eruption that has ever occurred, released a staggering 700 cubic miles (2,800 cubic km) of magma and left a thick layer of ash over all of South Asia. For comparison, the quantity of magma erupted from Indonesia's Mount Krakatau in 1883, one of the largest eruptions in recorded history, was about 3 cubic miles (12 cubic km).

Volcanologists continue to seek answers to many unanswered questions about supervolcanoes. For example, what triggers their eruptions, and why do they fail to erupt until their magma chambers achieve such enormous proportions? How does the composition compare to more familiar eruptions? And how can we predict when the next supervolcano will erupt?

But there's one thing that all experts agree on: supereruptions, though they occur, are exceedingly rare and the odds that one will occur in the lifetime of anybody reading this article are vanishingly small.

The most recent supereruption occurred in New Zealand about 26,000 years ago. The next most recent: the cataclysmic eruption of Mount Toba happened about 50,000 years earlier. In all, geologists have identified the remnant of about 50 supereruptions, though teams are in the process of evaluating a number of other possibilities.

That may sound like a large number. However, when one group of scientists used the count of all the known supervolcanoes to calculate the approximate frequency of eruptions, they found that only 1.4 supereruptions occur every one million years.

That's not to say that a supervolcano will occur every million years at regular intervals. Many millions of years could pass without a supereruption or many supervolcanoes could erupt in just a short period. The geological record does suggest supervolcanoes occur in clusters, but the clusters are not regular enough to serve as the basis for predictions of future eruptions.

Scientists have no way of predicting with perfect accuracy whether a supervolcano will occur in a given century, decade, or year – and that includes 2012. But they do keep close tabs on volcanically active areas around the world, and so far there's absolutely no sign of a supereruption looming anytime soon.

For more information concerning 2012, visit

› 2012: Beginning of the End or Why the World Won't End?
http://www.nasa.gov/topics/earth/features/2012.html
› 2012 - The Series
http://www.nasa.gov/topics/earth/features/2012-series.html

Susan Hendrix | EurekAlert!
Further information:
http://www.nasa.gov

More articles from Earth Sciences:

nachricht Volcanoes under pressure
18.11.2019 | Technical University of Munich (TUM)

nachricht New findings on the largest natural sulfur source in the atmosphere
18.11.2019 | Leibniz-Institut für Troposphärenforschung e. V.

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

Im Focus: Atoms don't like jumping rope

Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.

By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...

Im Focus: Images from NJIT's big bear solar observatory peel away layers of a stellar mystery

An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.

With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...

Im Focus: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

 
Latest News

Scientists first to develop rapid cell division in marine sponges

21.11.2019 | Life Sciences

First detection of gamma-ray burst afterglow in very-high-energy gamma light

21.11.2019 | Physics and Astronomy

Research team discovers three supermassive black holes at the core of one galaxy

21.11.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>