Scientists at the University of Tsukuba in Japan have identified a link between solar heat and earthquakes, suggesting that radiation from the sun can alter geological conditions in the Earth's crust and raise the likelihood of seismic movement.
The study found that solar activity, particularly sunspot cycles, affects the planet's surface temperature. That process influences how brittle rocks become, how underground water is distributed, and tectonic pressure, all of which can help release energy along seismic faults.
How heat could trigger seismic activity
The researchers determined that radiation from the sun causes slight temperature variations at the Earth's surface, with increases of between 0.1 and 0.2 degrees Celsius during periods of higher solar activity. Though the changes may seem small, they have a direct impact on the structure of the Earth's crust.
Rising temperatures alter the mechanical properties of rocks, making them more brittle and prone to fracturing. The heat also affects how groundwater is distributed, which can change tectonic pressure. Combined, these factors can act as triggers for earthquakes, especially in areas of high geological activity.
The researchers said the finding matters because traditional seismic models focus on internal processes within the Earth, while this research shows that external influences, such as space weather, can also play a significant role in seismic activity.
Sunspot activity and its cycles
Sunspots, regions of intense magnetic activity on the sun's surface, follow cycles of roughly 11 years, alternating between periods of minimum and maximum solar activity. During solar maximum, radiation emission increases and events such as solar storms and coronal mass ejections occur, affecting Earth's magnetosphere and potentially disrupting its thermal balance.
According to the study, shallow earthquakes, those occurring in the crust at depths of less than 70 kilometers, show a stronger correlation with sunspot activity. That pattern suggests increased solar radiation and its effect on surface temperature can influence the dynamics of tectonic plates.
Seismology still cannot predict exactly when and where an earthquake will occur, but understanding the sun's influence on seismic activity offers a new perspective on the factors that may contribute to it.
Could the finding improve earthquake prediction?
Adding solar activity as a variable in seismic models could improve the accuracy of earthquake prediction. Current seismic monitoring systems rely on geological and geophysical data, but the researchers said adding external indicators like temperature and solar cycles could strengthen early warning systems.
The study shows that including solar radiation and surface temperature in predictive models improves the identification of seismic patterns. While these factors are not the main triggers of earthquakes, their influence could help scientists better understand global seismic activity and reduce the impact of natural disasters on vulnerable populations.
