Through an atomic gravimeter, variations in gravity triggered by volcanic processes have been recorded
To detect the gravimetric effects of volcanic processes taking place in the superficial part of Etna's power system, demonstrating that quantum gravimeters can provide high-quality data, even in conditions where other technologies could not be used.
These are the results achieved by a study carried out by iXblue, a high-tech company specializing in the sectors of navigation, photonics applied to space and maritime autonomy, and the Etna Observatory of the National Institute of Geophysics and Volcanology (INGV-OE ), who, for the first time, observed subsurface mass variations on an active volcano, using an atomic gravimeter. The instrument was installed on Etna, Sicily. The results of this study were recently published in Geophysical Research Letters, a peer-reviewed journal of the American Geophysical Union (AGU).
Within the NEWTON-g project, funded through the European Union's H2020 programme, the Absolute Quantum Gravimeter (AQG), manufactured by iXblue, was improved to make it suitable for use in unfavorable environmental conditions and, subsequently, was been installed in the active summit area of Etna to test its potential as a tool for volcanic monitoring. Since then, AQG has recorded gravimetric data continuously and, in their publication, iXblue and INGV-OE present a time series of around 4 months.
The gravimeter was installed about 2,5 km from the active craters of Etna and recorded high quality data, despite the unfavorable environmental conditions (absence of electricity grid, strong temperature changes, presence of dust and corrosive volcanic gases) and the level of volcanic tremor.
“The AQG, installed in the summit area of Etna, has provided a good quality gravimetric time series and is unaffected by the instrumental problems affecting other gravimeters. Even under unfavorable environmental conditions, it was possible to detect small variations in gravity on different time scales, reflecting deep mass redistributions related to volcano dynamics", says Daniele Carbone, researcher at INGV-OE and co-author of the article.
Variations in the earth's gravitational field can reveal useful information on the characteristics of the subsoil: from the presence of tunnels and caves to the dynamics of groundwater and magma. iXblue's AQG is an easy-to-use, portable quantum sensor that measures changes in the gravitational field using a technology known as atomic interferometry. Using a cloud of rubidium atoms cooled to absolute zero as a sample mass, iXblue's AQG can detect tiny changes in gravity.
"Mass redistributions that occur beneath the Earth's surface, such as when magma moves through the feed system of an active volcano, can induce small changes in gravity over time, which can be detected by our AQG.". explains Vincent Menoret, R&D Manager at the iXblue Quantum Sensors division and co-author of the publication, adding that “recent progress in the development of quantum sensors, obtained by iXblue with its partners, has allowed the development of a portable gravimeter that has today demonstrated its ability to operate in even extreme conditions, making quantum technologies an industrial reality”.
“The results confirm the operational possibilities of quantum gravimeters and open new horizons for the application of gravimetry in geophysics. This outstanding result is also the clear demonstration of the maturity of cold atom technologies. A much larger impact can be expected in the field of neutral-atom quantum computers and long-distance quantum communication with Quantum Repeater Networks.”, concludes Jean Lautier-Gaud, of the iXblue Quantum Sensors division and co-author of the publication.
Studio:
L. Antoni-Micollier and al., Detecting volcano-related underground mass changes with a quantum gravimeter, Geophysical Research Letters (25 June 2022) / DOI: https://doi.org/10.1029/2022GL097814
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iXblue and the National Institute of Geophysics and Volcanology present the first application of quantum technology to volcano monitoring on Mount Etna
The world's first detection of gravity changes induced by volcanic processes was performed with a quantum gravimeter, a device which can provide high-quality data, even under conditions where other technologies could not be used.
These results were presented in a study carried out by iXblue, a high-tech company in the fields of navigation, photonics and space, and maritime autonomy, and the Osservatorio Etneo of the Istituto Nazionale di Geofisica e Volcanologia (INGV-OE). Their work was recently published in Geophysical Research Letters, a peer-reviewed journal of the American Geophysical Union (AGU).
In the frame of the NEWTON-g project, funded through the H2020 program of the European Union, the Absolute Quantum Gravimeter (AQG), manufactured by iXblue, was improved to make it suitable for use in adverse environmental conditions and, in August 2020, it was installed in the summit active area of Mt. Etna, to test its potential as an instrument for volcanic monitoring. Since then, the AQG has performed near-continuous gravity measurements and, in their publication, iXblue and INGV-OE present a four-month time series of gravity data. The gravimeter was installed at about 2.5 km from the active craters of Mt. Etna and produced continuous high-quality data, despite the unfavorable environmental conditions (lack of electricity, severe temperature changes, presence of dust and corrosive volcanic gases) and the high level of volcanic tremor.
“The AQG, installed in the summit crater zone of Mt. Etna, has provided a gravity time series free from the instrumental issues which affect other gravimeters. Even under unfavorable environmental conditions, it has been possible to detect small gravity changes over different time-scales, reflective of volcano-related underground mass changes” says Daniele Carbone, senior researcher at INGV-OE and co-author of the paper.
Variations in the Earth's gravitational field can reveal useful information about what lies underground: from the presence of tunnels and caves to the dynamics of groundwater and even magma. iXblue's AQG is a turn-key, portable and easy-to-operate quantum sensor, able to measure such variations of the gravity field using a quantum technology known as atomic interferometry. Using a cloud of laser-cooled rubidium atoms close to absolute zero as the test mass, iXblue's AQG can sense minute variations of gravity.
“Mass redistributions occurring below the Earth's surface, for example when magma is displaced through the feeding system of an active volcano, may induce tiny changes in gravity over time, which can be detected by our AQG” explains Vincent Menoret, R&D Manager at iXblue Quantum Sensors division and co-author of the publication, adding that “recent advances in the development of quantum sensors obtained by iXblue with its partners have allowed the development of a portable gravimeter which has proven today its ability to operate under field conditions, making quantum technologies an industrial reality”.
“The results confirm the operational possibilities of quantum gravimetry and open new horizons for the application of gravity measurements in geophysics. This outstanding achievement is also a clear demonstration of the maturity of cold-atom technologies. One can expect a much broader impact in the field of Quantum Computing with neutral atoms and Long-distance Quantum Communication with Quantum Repeaters” concludes Jean Lautier-Gaud, from IXblue Quantum Sensors division and co-author of the publication.
References:
L. Antoni-Micollier and al., Detecting volcano-related underground mass changes with a quantum gravimeter, Geophysical Research Letters (25 June 2022) / DOI: https://doi.org/10.1029/2022GL097814
Photo 1 - The INGV Pizzi Deneri Observatory at the active craters of Etna where the AQG has been installed (© D. Carbone)
Photo 1 - The INGV Pizzi Deneri Observatory nearby the active craters of Mount Etna, where the AQG was installed (© D. Carbone)
Photo 2 - Image of the AQG in front of the craters before its installation in the Pizzi Deneri Observatory (© iXblue)
Photo 2 - Picture of the AQG in front of the craters prior to its installation in the Pizzi Deneri observatory (© iXblue)