Autopsy of a eruption: Linking crystal growth to volcano seismicity

May 24, 2012
False colour image of zoned orthopyroxene crystal used in forensic-style analysis of Mount St Helens 1980 eruption. Credit: Dr Kate Saunders, University of Bristol

A forensic approach that links changes deep below a volcano to signals at the surface is described by scientists from the University of Bristol in a paper published today in Science. The research could ultimately help to predict future volcanic eruptions with greater accuracy.

Using forensic-style chemical analysis, Dr Kate Saunders and colleagues directly linked seismic observations of the deadly 1980 Mount St. Helens eruption to crystal growth within the magma chamber, the large underground pool of liquid rock beneath the volcano.

Over 500 million people live close to volcanoes which may erupt with little or no clear warning, causing widespread devastation, disruption to aviation and even global effects on climate. Many of the world's volcanoes are monitored for changes such as increases in seismicity or . However, an on-going problem for is directly linking observations at the surface to processes occurring underground.

Dr Saunders and colleagues studied zoned crystals, which grow concentrically like tree rings within the magma body. Individual zones have subtly different chemical compositions, reflecting the changes in physical conditions within the magma chamber and thus giving an indication of and the timescales over which they occur.

Chemical analysis of the crystals revealed evidence of pulses of magma into a growing chamber within the volcano. Peaks in crystal growth were found to correlate with increased seismicity and in the months prior to the eruption.

Dr Saunders said: "Such a correlation between crystal growth and volcanic seismicity has been long anticipated, but to see such clear evidence of this relationship is remarkable."

This forensic approach can be applied to other to shed new light upon the nature and timescale of pre-eruptive activity. This will help scientists to evaluate monitoring signals at restless volcanoes and improve forecasting of future eruptions.

Explore further: New detector sniffs out origins of methane

More information: 'Linking Petrology and Seismology at an Active Volcano' by Kate Saunders, Jon Blundy, Ralf Dohmen, Kathy Cashman in Science.

Related Stories

Volcanic Quakes Help Forecast Eruptions

Dec 22, 2009

Monitoring the earthquakes caused from magma movements inside an active volcano could help to improve the accuracy of forecasting an eruption.

Eruptive characteristics of Oregon's Mount Hood analyzed

Aug 02, 2010

A new study has found that a mixing of two different types of magma is the key to the historic eruptions of Mount Hood, Oregon's tallest mountain, and that eruptions often happen in a relatively short time ...

Magma chambers awake sooner than thought

Mar 07, 2011

Until now it was thought that once a volcano's magma chamber had cooled down it remained dormant for centuries before it could be remobilized by fresh magma. A theoretical model developed by Alain Burgisser of the Orléans ...

Recommended for you

Stuck-in-the-mud plankton reveal ancient temperatures

1 hour ago

New research in Nature Communications showing how tiny creatures drifted across the ocean before falling to the seafloor and being fossilised has the potential to improve our understanding of past climat ...

NASA sees Mozambique Channel's new tropical storm

1 hour ago

Tropical Cyclone 15S formed in the Mozambique Channel of the Southern Indian Ocean, and the Global Precipitation Measurement or GPM core satellite gathered data on its rainfall rates.

How rain is dependent on soil moisture

1 hour ago

It rains in summer most frequently when the ground holds a lot of moisture. However, precipitation is most likely to fall in regions where the soil is comparatively dry. This is the conclusion reached by ...

ESA image: Hungarian mosaic

2 hours ago

This image of Hungary, with the political border in white, is a mosaic of 11 scans by Sentinel-1A's radar from October to December 2014.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.