Device designed for extraterrestrial use could detect CO2 leaks

Researchers from the University of Tokyo and Kyushu University have designed a geophysical research device on the Moon and Mars, which could also help combat climate change on Earth.

The Portable Active Seismic Source (PASS), originally designed for use in space, could have important uses on the planet where it was developed.

The team of researchers led by the University of Tokyo and Kyushu University found that the device could help advance carbon sequestration technology by providing continuous subsurface monitoring at scale. one kilometer to detect carbon dioxide leaks.

Underground features such as carbon reservoirs can be monitored using seismic waves, generated either by earthquakes or man-made sources. But seismic monitoring typically requires large and expensive machines, making continuous monitoring at the scales needed for carbon reservoirs cost-prohibitive and practically difficult.

In contrast, PASS is an ultra-compact centimeter-scale seismic source that can solve this problem by enabling continuous monitoring of carbon reservoirs.

“Due to the small size of the device, the vibrations it produces are relatively small, but when these vibrations are produced continuously, the resulting signals can be stacked, allowing transmission over long distances,” said the lead researcher, Professor Takeshi Tsuji.

“With a four centimeter motor, the signal could be transmitted over a kilometer – the scale needed to monitor the strata used to store carbon dioxide.”

(a) Seismic source system commonly used for imaging and monitoring underground reservoirs. (b) Meter-scale continuous monitoring source system. (c) Centimeter-scale continuous monitoring source system developed in this study. / Takeshi Tsuji

Image credit: Takeshi Tsuji

Originally, PASS was designed for extraterrestrial uses, such as geophysical research on the Moon and Mars. However, IIts small size makes deploying and operating the PASS much more affordable than conventional seismic sources, which are typically several meters in size.

The ultra-compact device can be powered by a 12V car battery, and can even be deployed by drone in otherwise inaccessible areas. To test this, the researchers conducted experiments with PASS at two field sites, one on a bank and one on a tailings dam in a mining area.

“The PASS system has great potential for a wide variety of scientific and engineering applications, including monitoring potential disasters such as landslides and volcanoes, and imaging man-made structures such as tunnels, dams and embankments,” Tsuji said.

The affordability and convenience of continuous underground monitoring using this newly developed PASS technology could enable the detection of sudden changes in reservoirs and thus avoid dangerous CO2 the leaks.

Scientists hope these experiments will make the technology particularly valuable for the development of carbon sequestration projects, and perhaps also encourage public acceptance of these and other geoengineering projects.

Their findings were published in the journal Seismological research letters.

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