The release of radon (222Rn) gas from underground. The concentration of radon in the atmosphere is measured at radioisotope (RI) facilities.
Radon exhalates to the ground surface through microcracks (fissures) in the rock that occur before and after earthquakes.
All of this suggests that radon levels did not increase after the earthquake. It also paints a more complicated picture of the radon and fluid movements that cause radon exhalation in the subsurface when large earthquakes occur.
"The discovery revealed that more processes are occurring before earthquakes than previously thought," said Muto. "Further analysis of other earthquakes will lead to a better understanding of the physiochemical processes at play and help us use atmospheric radon concentrations to clarify various crustal movements correlated with major earthquakes."
The research group has established atmospheric radon concentration measurement monitoring networks at radioisotope facilities across Japan.
Monitoring is also expected be carried out at nuclear power plants.
Expansion of the monitoring network will help clarify the area and timing of radon anomalies, the geological characteristics that cause such anomalies, and the relationship with the different earthquake types. All of this will help realize a radon-based earthquake prediction system.
Explore further
Revisiting the Kobe earthquake and the variations of atmosp.heric radon concentration
More information: Jun Muto et al. Preseismic atmospheric radon anomaly associated with 2018 Northern Osaka earthquake, Scientific Reports (2021). DOI: 10.1038/s41598-021-86777-z
Journal information: Scientific Reports
Provided by Tohoku University
https://phys.org/news/2021-04-preseismic-atmospheric-radon-anomaly-northern.html
The release of radon (222Rn) gas from underground. The concentration of radon in the atmosphere is measured at radioisotope (RI) facilities. Radon exhalates to the ground surface through microcracks (fissures) in the rock that occur before and after earthquakes.
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