Sun May Help Trigger Earthquakes, Scientists Claim

Heat from the Sun may play a role in triggering quakes here on Earth—a finding that could be used to improve earthquake predictions by factoring in solar forecasts too.

This is the conclusion of an international team of researchers from Brazil and Japan, whose modeling links solar and seismic activity via the Sun's effect on Earth's atmosphere.

The team cautions that the effect of solar heat on earthquakes may only be minute, but such could still be a significant piece of the larger puzzle.

"It's an exciting direction—and we hope our study sheds some light on the bigger picture of what triggers earthquakes," said paper author and computer scientist Matheus Saldanha of the University of São Paulo, Brazil, in a statement.

Earthquakes occur as a result of the constant—but, to us, imperceptibly slow—movement of tectonic plates across the Earth's surface, which causes stress to build up in the crust.

When this stress overcomes either the strength of the rock, creating a new fault; or overcomes the friction along existing fault planes, the ground slips—releasing waves of energy that we feel as earthquakes.

The study builds on previous research—published back in 2022—that found an association between sunspot numbers and seismic activity here on Earth.

That analysis found that the accuracy of next-day earthquake magnitude prediction could be improved by 2.6—17.9 percent when solar activity data was factored in.

In their latest study, the researchers analyzed earthquake data alongside records of both solar activity and Earth surface temperatures.

"Solar heat drives atmospheric temperature changes, which in turn can affect things like rock properties and underground water movement," Saldanha explained.

"Such fluctuations can make rocks more brittle and prone to fracturing, for example—and changes in rainfall and snowmelt can alter the pressure of tectonic plate boundaries.

"While these factors may not be the main drivers of earthquakes, they could still be playing a role that can help to predict seismic activity."

In fact, the team noted, when they fed details of Earth surface temperature in to their seismic modeling, such became more accurate—particularly in the case of shallow earthquakes.

"This makes sense, since heat and water mostly affect the upper layers of the Earth's crust," Saldanha said.

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References

Saldanha, M., & Hirata, Y. (2022). Solar activity facilitates daily forecasts of large earthquakes. Chaos. https://doi.org/10.1063/5.0096150

Saldanha, M., Shiro, M., Yagi, Y., & Hirata, Y. (2025). The role of solar heat in earthquake activity. Chaos. https://doi.org/10.1063/5.0243721