Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A look inside volcanic flows

13.09.2016

Research attempts to better understand deadly pyroclastic flows

An empty boiler house and 1.5 tons of thick volcanic ash have given researchers at New Zealand's Massey University and Georgia Tech a look into the inner workings of pyroclastic flows in the largest-scale experiments of volcanic flows that have been conducted. They saw something they didn't expect.


Researchers created their own flows with 3,500 pounds of volcanic ash

Credit: Massey University

In a paper published last week by Nature Geoscience, the team describes two separate transport areas that have been well-studied: a non-turbulent underflow and a fully turbulent, ash cloud region at the top of the flow. But volcanic flows apparently have a previously unrecognized third zone where the currents meet.

"Inside this middle zone, the gas-particle mixture behaved fundamentally differently from the turbulent suspension cloud above and the particle-rich avalanche of pumice below," said Massey's Gert Lube. "These mesoscale turbulence clusters control how the internal structure and the damage potential of pyroclastic flows evolves during volcanic events."

Pyroclastic flows, like the ones that covered Pompeii, are avalanches of fast-moving clouds of hot ash, rock and gas that are emitted during eruptions. They are responsible for 50 percent of volcanic fatalities every year.

"Our experiments allow us to better understand the physics of something we'll never see: the inside of an actual volcanic flow," said Massey's Eric Breard, the lead author who will begin a postdoctoral fellowship at Georgia Tech in January. "By studying how quickly this mesoscale region grows, and how its dynamics change, it ultimately can tell us how dangerous the flows can be."

To create and measure the flows, the team used Massey's one-of-a-kind eruption simulator. The team climbed a 12-meter tower in a repurposed boiler house and poured more than 3,500 pounds of pumice and ash down a 12-meter narrow chute. High-speed cameras recorded the flow while sensors captured the data.

"These experiments demonstrated that in the intermediate transition zone between the fully turbulent upper part of the flow and the underlying concentrated underflow, the energy from the largest scales of fluid motion is extracted by particles that almost exactly follow the fluid motion," said co-author Josef Dufek, an associate professor at Georgia Tech. "This creates dendritic structures, or waves of particles, that slow the flow down, and provide the rate-limiting step for particles entering the underflow where they can cause the most damage."

"This opens a new path toward reliable predictions of their motion, and will be particularly topical for hazard scientists and decision makers, because they will lead to major revisions of volcanic hazard forecasts and ultimately more effective measures for keeping people safe," said Lube.

###

Massey and Georgia Tech also received support from scientists at the University of Auckland and State University of New York.

Media Contact

Jason Maderer
maderer@gatech.edu
404-660-2926

 @GeorgiaTech

http://www.gatech.edu 

 

Mysteries of volcanic avalanches unlocked | Massey University

 

Video: https://www.youtube.com/watch?v=IyucKa1egVA

 

Jason Maderer | EurekAlert!

Further reports about: Nature Geoscience Pyroclastic pyroclastic flows volcanic volcanic ash

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>