Synchrotron techniques powerful tool to reveal inner workings of volcanoes

An article in Nature Geosciences has highlighted the power of synchrotron techniques to reveal the inner workings of volcanic systems that could potentially help with predictions of eruptions.

Assoc Prof Tessa Ubide, an Australian Research Council Future Fellow and Associate Professor in Igneous Petrology/Volcanology at The University of Queensland uses X-ray fluorescence microscopy at ANSTO’s Australian Synchrotron to investigate samples that contain an important environmental proxy.

Crystals of clinopyroxene, a calcium, magnesium and iron-bearing silicate mineral containing minor elements like sodium and trace elements including chromium, retain a memory of volcanic processes.

X-ray fluorescence microscopy detects and provides a visual map of the presence of metals in a sample, such as clinopyroxene. Important chemical information can be gathered from the data.

“Knowing what inner mechanisms trigger volcanoes to erupt is crucial to help interpret whether signs of volcanic unrest, such as earthquakes recording magma movement at depth, may herald an eruption, said A/Prof Ubide. 

“It becomes a special crystal ball — instead of showing the future directly, it shows a past of storage and eruption processes that are key to forecasting future volcanism.” 

“Clinopyroxene is such an enigmatic mineral, being used to identify meteorites and to understand ore deposits among many other things. To see it used to understand how volcanos can erupt is extremely interesting,” said beamline scientist Dr Andrew Langendam (pictured above). 

“The work done by A/Prof Ubide really showcases the capabilities of the XFM beamline at the Australian Synchrotron, being able to scan large areas for these indicator metals at high resolution quickly. These samples really benefit from this fast-scanning technique.” 

Read more on ANSTO website

Microscale clues provide insight into cataclysmic Tongan volcanic eruption

Key Points
  • The intensely powerful and destructive Hunga blast was unlike previous events, It was a unique event in that scientists were able to capture the eruption with satellite imagery and other instruments.
  • The Hunga volcano started out with a flat upper surface to a depth of 150 metres before the eruption, which ejected at least 6.5 cubic kilometres of ash and rock and left a deep caldera 250 metres below sea level.
  • Electron microscopy revealed different concentrations of chemicals in the two types of magma that came together and mingled to form distinctive swirling bands in the samples. Infrared beamline analysis techniques provided crucial information about the diffusion of water in the tiny fragments.
  • The chilling effect of the water as the magma fragmented, the concentration of water and the chemical composition of the particles also provided clues about the depth at which the event occurred.

When the Tongan Hunga volcano erupted in January this year, it was a huge explosion with a mass ejection that reached more than 55 kilometres into the atmosphere, causing local fatalities and evacuations. The blast created significant tsunami waves in the Pacific Basin and generated pressure waves that encircled the globe.

Although not a significant inundation,  the impact of the tsunami reached Australia with waves of 82cm at the Gold Coast, 65cm at Port Kembla and 77cm at Eden’s Twofold Bay in NSW.

In an effort to understand why the eruption was so explosive, internationally-recognised volcanologist Prof. Shane Cronin of the University of Auckland and associates rely on beamlines at the Australian Synchrotron to support comprehensive research on the Hunga event.

Two sets of experiments have already been carried on the Imaging and Medical beamline and the Infrared Microspectroscopy beamline, while another investigation is scheduled for the X-ray fluorescence microscopy beamline.

Read more on the ANSTO website

Image: Undersea volcano