Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mega Eruption of Yellowstone’s Southern Twin

29.03.2006


North America isn’t the only continent that’s experienced super-colossal volcanic eruptions in the recent geologic past. The massive explosion of the almost unknown Vilama Caldera in Argentina appears to have matched Yellowstone’s last continent-blanketing blast. It may, in fact, be just one of several unappreciated supervolcanoes hidden in a veritable mega-volcano nursery called the Eduardo Avaroa Caldera Complex, located in the inhospitable Puna-Altiplano region near the tri-section of Argentina, Bolivia, and Chile.



"Vilama Caldera formed during a single event that emitted approximately 2000 cubic kilometers (almost 500 cubic miles) of pyroclastic material," said geologist Miguel M. Soler of the National University of Jujuy in San Salvador de Jujuy, Argentina. The volume of ash and pyroclastic material, called ignimbrites, produced by the 8.4 million-year-old eruption, and the size of the associated caldera, put it among the world’s largest known eruptions, he says.

"In contrast, for example, Yellowstone produced its important volumes of ignimbrites and lavas in three cataclysmic events. Eruptions at 2.0, 1.3, and 0.6 million years ago ejected huge volumes of rhyolite magma, and each formed a caldera and extensive layers of thick pyroclastic flow deposits," said Soler. Soler will present some of the recent groundbreaking work on Vilama supervolcano on Monday, 3 April at Backbone of the Americas - Patagonia to Alaska. The meeting is co-convened by the Geological Society of America and the Asociación Geológica Argentina, with collaboration of the Sociedad Geológica de Chile. The meeting takes place 3-7 April in Mendoza, Argentina.


The Vilama Caldera appears to have been created when the 10 by 24-mile roof catastrophically collapsed on a chamber of molten rock, or magma, explosively venting vast amounts of ignimbrites out in various directions. That massive roof collapse is the one thing all large calderas have in common and what separates them from the exponentially smaller "single vent" volcanic eruptions like Mount St. Helens or Mount Pinatubo.

But that’s where the similarities with Yellowstone end, says Soler. The magma under Yellowstone is thought to be created by the melting of ancient crust under North America, buoying back up and creating a hot spot. Vilama’s magma was probably created by a more complex melting of the crust caused by the South American Plate colliding with and overriding the Nazca Plate to the west. The resulting kneading of the crust — the thickening and thinning, pressurizing and depressurizing — caused large pockets of rock to melt and eventually led to a series of gigantic caldera eruptions.

The trigger for the Vilama mega-eruption, says Soler, was probably the same thing that gave the caldera its football-like shape: The tectonic faults in the roof of the magma chamber which probably formed as a consequence of its own instability and/or from the significant stresses in the crust in that area. The crystal-rich nature of the ignimbrites and minimal signs of pre-eruption gases also point to an external trigger for the vast eruption, says Soler.

Much remains unknown about Vilama Caldera, says Soler, largely because it is a terribly difficult caldera to study. Unlike Yellowstone, which has the Yellowstone River cutting through it and exposing the layers of volcanic rock, called stratigraphy, for easy reading by geologists, Vilama is in one of the driest places on Earth.

"There is not much topographic relief to permit viewing of many complete columns of stratigraphy," said Soler. What’s more, most of the region is more than 13,000 feet above sea level, which makes field work in the area particularly physically demanding, as well. All this also explains why Vilama is just the first of several important calderas in the region that deserve a lot more scientific attention, he said.

"Among the other calderas in the region that need to be studied in detail and which in all cases are also certainly ’supervolcanoes’ are Cerro Guacha, Coruto, Pastos Grandes, and Capina," said Soler.

The study of these supervolcanoes is not an end in itself, according to Soler. Figuring out their histories and how and why they erupted will help geologists grasp the regional forces that have been at work in one of the Earth’s thickest patches of crust, as well as give clues to other calderas worldwide.

WHERE & WHEN
Backbone of the Americas - Patagonia to Alaska
Centro de Congresos
Mendoza, Argentina
Thursday, 6 April 2006

Ann Cairns | EurekAlert!
Further information:
http://www.geosociety.org

More articles from Earth Sciences:

nachricht Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America

nachricht Ice stream draining Greenland Ice Sheet sensitive to changes over past 45,000 years
14.05.2018 | Oregon State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>