The Sun Might Be Influencing Earthquakes, Scientists Say

Seismologists know a lot about the mechanics of earthquakes and why they occur. What’s more difficult to determine, however, is how to predict future earthquakes. And while associating earthquakes with solar or lunar activity might sound like a conspiracy theory, recent research suggests a possible link between the Sun’s heat and seismic activity.

Researchers in Japan discovered that computer models incorporating Earth’s surface temperatures simulated past earthquakes more accurately. Their study, published Tuesday in the journal Chaos, reveals that the Sun’s impact on Earth’s surface might influence our planet’s seismic activity. If validated, these results could revolutionize earthquake prediction and, as a consequence, our ability to prepare.

A 2022 study by some of the same authors had previously established that solar activity, including sunspots, impacts seismicity on our planet. “However, the mechanisms by which the Sun can affect seismic activity on Earth are still unknown,” the researchers wrote in the recent study. “Here, we examine the hypothesis that one of such influences is through heat.”

The researchers concluded that heat affects Earth’s seismicity by comparing earthquake data with solar activity and the planet’s surface temperatures. They found that incorporating surface temperatures into earthquake simulations improved their accuracy, especially for shallow earthquakes.

This implies that the temperature of Earth’s crust—which is itself influenced by the Sun’s heat—is somehow involved in seismic activity. They also cited seasonal variations in earthquakes as further evidence.

“Solar heat drives atmospheric temperature changes, which in turn can affect things like rock properties and underground water movement,” Matheus Henrique Junqueira Saldanha, a co-author on the study and a computer scientist at the University of Tsukuba, said in an AIP Publishing statement. The journal Chaos is published by AIP Publishing.

“Such fluctuations can make rocks more brittle and prone to fracturing, for example — and changes in rainfall and snowmelt can alter the pressure on 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,” he continued. Researchers from Japan’s National Institute of Advanced Industrial Science and Technology also took part in the study.

Additionally, the strong link between surface temperatures and shallow earthquakes “makes sense, since heat and water mostly affect the upper layers of the Earth’s crust,” Junqueira Saldanha explained.

The connection between solar heat, surface temperature, and earthquakes could hold important implications for earthquake prediction and protecting people in seismically active regions. “It’s an exciting direction,” Junqueira Saldanha concluded, “and we hope our study sheds some light on the bigger picture of what triggers earthquakes.”