Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions

30.11.2016

Temperature and water content cycles within magma reservoirs linked to eruptive style

A new study published in Geology uses pockets of melts trapped within crystals to understand the conditions occurring beneath volcanoes before explosive eruptions. Volcanologists from Johannes Gutenberg University Mainz (JGU), Leibniz Universität Hannover in Germany and Uppsala University in Sweden have discovered that the temperature and water content of magmas varies through the lifecycle of a volcano, and that these variations occur in cycles in relation to the fresh input of new magma from below.


Volcanic crater of Kelud in Indonesia

photo/©: Mike Cassidy, JGU

The study suggests that the point at which an eruption occurs within these cycles may control whether the resulting eruption is explosive, which produces lots of ash and affects a wide geographical region, or simply erupts effusively creating lava flows or domes, lessening the hazards to nearby populations.

The study was conducted on Kelud volcano in Indonesia, which is considered to be one of the most dangerous volcanoes in the world, with more than two million people living within 30 kilometers of it, and a death toll of more than 5,000 people killed in eruptions in the last century alone.

Kelud erupted explosively as recently as 2014, dispersing ash more than 200 kilometers away, leading to the evacuation of 200,000 people, closing three international airports and killing several people. But Kelud, like many volcanoes, is unpredictable in the sense that it often changes the way it erupts. In 2014 the eruption was explosive, but in 2007 the eruption produced little ash and instead created a small lava flow within the crater.

The researchers found that before the 2014 explosive eruption at Kelud, the magma was in a cool and water-rich state, whereas in 2007, before the less explosive lava dome eruption, the magma was hotter and dryer.

"Even relatively small changes in the temperature and water content of the magma can drastically alter the chemical and physical properties of the unerupted magma," explained lead author Dr. Mike Cassidy from the Institute of Geosciences at Mainz University. "For instance, when the temperature drops, this makes the magma stickier, which means the gas finds it harder to escape, thus building up pressure leading to an explosive eruption."

The hotter and dryer magma conditions are attributed to the fresh input of water-poor magma from below, which mixes and thus dilutes the magma in water content. The study goes some way to explaining why volcanoes erupt in different ways and could in the future help to forecast how explosive an impending eruption will be.

Publication:
Mike Cassidy et al.
Volatile dilution during magma injections and implications for volcano explosivity
Geology, December 2016
DOI: 10.1130/G38411.1

Images:
http://www.uni-mainz.de/bilder_presse/09_geo_vulkanologie_magma_reservoir_01.jpg
Kelud in Indonesia, one of the most dangerous volcanoes in the world
photo/©: Mike Cassidy, JGU

http://www.uni-mainz.de/bilder_presse/09_geo_vulkanologie_magma_reservoir_02.jpg
Volcanic crater of Kelud in Indonesia
photo/©: Mike Cassidy, JGU

http://www.uni-mainz.de/bilder_presse/09_geo_vulkanologie_magma_reservoir_03.jpg
Pumice stone from the 2014 explosive eruption of Kelud
photo/©: Mike Cassidy, JGU

http://www.uni-mainz.de/bilder_presse/09_geo_vulkanologie_magma_reservoir_04.jpg
Inclusion of liquid rock (small black dots) in feldspar crystals, which were used to study the change of magma in the Earth’s crust
photo/©: Mike Cassidy, JGU

Contact and further information:
Dr. Mike Cassidy
Volcanology
Institute of Geoscicences
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-27004
e-mail: mcassidy@uni-mainz.de
https://sites.google.com/site/drmikecassidyvolcanoscientist/home

Weitere Informationen:

http://www.geowiss.uni-mainz.de/714_ENG_HTML.php ;
http://www.vulkanologie.uni-mainz.de/Site/Mike_Cassidy.html ; http://geology.gsapubs.org/content/44/12/1027.abstract?etoc

Petra Giegerich | idw - Informationsdienst Wissenschaft

Further reports about: Earth’s crust explosive eruptions magma volcanic eruptions volcanoes

More articles from Earth Sciences:

nachricht A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution

nachricht Environmental history told by sludge: Global warming lets the dead zones in the Black Sea grow
10.01.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>