A new study (ref.) suggests the existence of a relationship between the amount of cosmic rays hitting the Earth and the intensity of earthquakes. The team of Polish researchers analyzed 50 years of data. The intensity of global seismic activity is correlated with the average variation in the intensity of secondary particles created by cosmic radiation over a period of about two weeks.
Secondary particles are produced when cosmic rays impact the Earth’s atmosphere. By colliding with gas molecules, they trigger cascades of secondary particles in the stratosphere. Therefore, the link between the two phenomena may have nothing to do with the intensity of cosmic rays. But rather with their ability to breach Earth’s defenses.
The team stated that they have ruled out the possibility that the observed correlation was random. If the relationship between cosmic rays and earthquakes is confirmed, scientists could use it to better predict powerful seismic events that cause significant structural damage and human casualties.
“The idea that there is a connection between earthquakes and cosmic rays, which mainly come from the Sun and deep space, may seem strange” said Piotr Homola, coordinator of the Cosmic Ray Extremely Distributed Observatory (CREDO), in a statement. “However, its physical foundations are entirely rational”.
CREDO is a virtual international observatory that collects and processes data from a range of cosmic ray detectors, from sophisticated scientific instruments scattered around the planet to regular smartphones of volunteers. Its main purpose is to monitor global changes in the cosmic radiation flux.
Magnetosphere and Secondary Particles
Scientists believe that the strange correlation between cosmic radiation and seismic activity could be explained by the behavior of eddy currents in the Earth’s liquid core that generate the magnetic field. This magnetic field, known as the magnetosphere, is responsible for deflecting charged particles of cosmic radiation.
Major earthquakes may be associated with disruptions in the flow of matter that drives the Earth’s dynamo, which also affects the magnetosphere. In turn, it would influence the ability of primary charged particles to penetrate the planet’s atmosphere, which would impact the quantity of secondary particles.
The CREDO team examined data on cosmic ray intensity collected from the Neutron Monitor Database project and the Pierre Auger Observatory. The datasets were compared with changes in solar activity, solar influence data, and seismic activity information recorded by the US Geological Survey program.
Through statistical analysis, scientists noticed a correlation between changes in the intensity of secondary particle production and the sum of all earthquakes with a magnitude equal to or greater than four. This correlation only manifested when cosmic ray data was shifted by 15 days compared to seismic data.
A Real Correlation
Could this correlation be used to predict the location of a powerful earthquake? Changes in cosmic ray intensity and earthquakes were correlated by considering seismic activity on a global scale. However, the correlation disappears when analyzing the phenomenon locally.
“In the scientific world, it is accepted that a discovery can be claimed when the statistical confidence level of the data reaches five sigma” explained Homola. “We have obtained over six sigma. It means a probability of less than one in a billion that the correlation is due to chance. Therefore, we have an excellent statistical basis to claim that we have discovered an existing phenomenon”.
“The most important thing is that we have demonstrated a connection between recorded cosmic radiation and seismicity. If there is one thing we can be certain of, it is that our observation points and research opportunities are completely new and exciting” Homola concluded.