. 24/7 Space News .
SHAKE AND BLOW
Size matters: if you are a bubble of volcanic gas
by Staff Writers
Cambridge UK (SPX) Aug 07, 2018

file image

The chemical composition of gases emitted from volcanoes - which are used to monitor changes in volcanic activity - can change depending on the size of gas bubbles rising to the surface, and relate to the way in which they erupt. The results, published in the journal Nature Geoscience, could be used to improve the forecasting of threats posed by certain volcanoes.

A team of scientists, including a volcanologist and mathematician from the University of Cambridge, discovered the phenomenon through detailed observations of gas emissions from K?lauea volcano in Hawaii.

At many volcanoes around the world, gas emissions are monitored routinely to help with forecasting eruptions. Changes in the output or proportions of different gases - such as carbon dioxide and sulphur dioxide - can herald shifts in the activity of a volcano.

Volcanologists have considered that these chemical changes reflect the rise and fall of magma in the Earth's crust but the new research reveals that the composition of volcanic gases depends also on the size of the gas bubbles rising up to the surface.

Until the latest spectacular eruption opened up fissures on the flank of the volcano, K?lauea held a vast lava lake in its summit crater. The behaviour of this lava lake alternated between phases of fiery 'spattering' powered by large gas bubbles bursting through the magma, and more gentle gas release, accompanied by slow and steady motion of the lava.

In the past, volcanic gases have been sampled directly from steaming vents and openings called fumaroles. But this is not possible for the emissions from a lava lake, 200 metres across, and at the bottom of a steep-sided crater. Instead, the team used an infrared spectrometer, which is employed for routine volcano monitoring by co-authors of the study, Jeff Sutton and Tamar Elias from the Hawaiian Volcano Observatory (US Geological Survey).

The device was located on the edge of the crater, pointed at the lava lake, and recorded gas compositions in the atmosphere every few seconds. The emissions of carbon- and sulphur-bearing gases were measured during both the vigorous and mild phases of activity.

Each individual measurement was used to compute the temperature of the volcanic gas. What immediately struck the scientists was that the gas temperatures ranged from 1150 degrees Celsius - the temperature of the lava - down to around 900 degrees Celsius.

"At this temperature, the lava would freeze," said lead author Dr Clive Oppenheimer, from Cambridge's Department of Geography. "At first, we couldn't understand how the gases could emerge much colder than the molten lava sloshing in the lake."

The clue to this puzzle came from the variation in calculated gas temperatures - they were high when the lava lake was placid, and low when it was bubbling furiously. "We realised it could be because of the size of the gas bubbles," said co-author Professor Andy Woods, Director of Cambridge's BP Institute.

"Larger bubbles rise faster through the magma and expand rapidly as the pressure reduces, just like bubbles rising in a glass of fizzy drink; the gas cools down because of the expansion." Larger bubbles form when smaller bubbles bump into each other and merge.

Woods and Oppenheimer developed a mathematical model to account for the process, which showed a very good fit with the observations.

But there was yet another surprising finding from the gas observations from Hawaii. As well as being cooler, the emissions from the large gas bubbles were more oxidised than expected - they had higher proportions of carbon dioxide to carbon monoxide.

The chemical balance of volcanic gases such as carbon dioxide and carbon monoxide (or sulphur dioxide and hydrogen sulphide) is generally thought to be controlled by the chemistry of the surrounding liquid magma but what the new findings showed is that when bubbles get large enough, most of the gas inside follows its own chemical pathway as the gas cools.

The ratio of carbon dioxide to carbon monoxide when the lava lake was in its most energetic state was six times higher than during the most stable phase. The scientists suggest this effect should be taken into account when gas measurements are being used to forecast major changes in volcanic activity.

"Gas measurements are critical to our monitoring and hazard assessment; refining our understanding of how magma behaves beneath the volcano allows us to better interpret our observations," said co-author Tamar Elias from the Hawaiian Volcano Observatory.

And there is another implication of this discovery - not for eruptions today but for the evolution of the Earth's atmosphere billions of years ago. "Volcanic emissions in Earth's deep past may have made the atmosphere more oxidising than we thought," said co-author Bruno Scaillet.

"A more oxygen-rich atmosphere would have facilitated the emergence and viability of life on land, by generating an ozone layer, which shields against harmful ultraviolet rays from the sun."

Research paper


Related Links
University of Cambridge
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


SHAKE AND BLOW
Yellowstone super-volcano has a different history than previously thought
Blacksburg VA (SPX) Jul 30, 2018
The long-dormant Yellowstone super-volcano in the American West has a different history than previously thought, according to a new study by a Virginia Tech geoscientist. Scientists have long thought that Yellowstone Caldera, part of the Rocky Mountains and located mostly in Wyoming, is powered by heat from the Earth's core, similar to most volcanoes such as the recently active Kilauea volcano in Hawaii. However, new research published in Nature Geoscience by Ying Zhou, an associate professor with ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
Blend of novices, veterans to fly on first private US spaceships

NASA, Commercial Partners Progress to Human Spaceflight Home Stretch

NASA makes progress toward planetary science decadal priorities

NASA Assigns Crews to First Test Flights, Missions on Commercial Spacecraft

SHAKE AND BLOW
First SLS Core Stage flight hardware complete, ready for joining

Aerojet Rocketdyne boosters complete simulated air-launch tests

China's newest micro-rocket has fast production cycle

India Working on Augmenting Power of Electric Propulsion for Heavier Satellites

SHAKE AND BLOW
Sorry Elon Musk, but it's now clear that colonising Mars is unlikely

Mars Dust Storm May Have Peaked

Russia Plans to Send Capsule With Microorganisms to Mars

Students can now build their own rover model

SHAKE AND BLOW
China to launch space station Tiangong in 2022, welcomes foreign astronauts

Growing US unease with China's new deep space facility in Argentina

China solicits international cooperation experiments on space station

China developing in-orbit satellite transport vehicle

SHAKE AND BLOW
Bangladesh PM opens satellite ground stations

Seventh set of Iridium NEXT satellites performing well during pre-operational testing

Telesat signs consortium deal with Thales and SSL new LEO constellation

Thales and SSL form consortium to further design and develop Telesat's LEO constellation

SHAKE AND BLOW
Ricocheting radio waves monitor the tiniest movements in a room

Loft Orbital announces inSpace mission partner program to standardize access to space

UCF professor discovers a first-of-its-kind material for the quantum age

Aboard the ISS, researchers investigate complex dust behavior in plasmas

SHAKE AND BLOW
VLA Detects Possible Extrasolar Planetary-Mass Magnetic Powerhouse

Largest haul of extrasolar planets for Japan

TESS catches a comet before starting planet hunting mission

Exoplanets where life could develop as on Earth

SHAKE AND BLOW
New Horizons team prepares for stellar occultation ahead of Ultima Thule flyby

Million fold increase in the power of waves near Jupiter's moon Ganymede

High-Altitude Jovian Clouds

'Ribbon' wraps up mystery of Jupiter's magnetic equator









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.