A new theory suggests that heavy snowfall may be a factor in triggering swarms of earthquakes — evidence that what’s happening above and below the Earth’s surface may play a role in underground events.
A study says The study was published Wednesday in the journal Science AdvancesThis points to a possible link between heavy snowfall on Japan’s Noto Peninsula and the thousands of earthquakes measured there since late 2020.
This is one of the first studies to link weather or climate changes to earthquake activity.
„Those large glaciation events seem to correlate well with the initiation of these large earthquake swarms,” said study author William Frank, assistant professor of Earth, Atmospheric and Planetary Sciences at the Massachusetts Institute of Technology. „We should not forget that climate can also play a role in changing the stress level at the depth at which earthquakes occur.”
The study does not suggest that climate or weather changes directly cause earthquakes. Instead, it suggests that the rate of earthquakes in a given region may increase or decrease due to changes in how water moves beneath the surface and how much pressure the weight of the ice exerts.
David Shelley, a research geophysicist at the United States Geological Society, said the study raises interesting questions, but more research is needed to verify its findings.
„What they show is that seismicity starts and seems to increase following these periods of snow. It’s an intriguing observation, and I’m not sure it’s conclusive,” he said.
However, Shelley expects other seismologists to be interested in the research.
„This sequence is a subject of great interest in the community. This is the first paper to suggest that there may be an environmental factor,” Shelley said.
The study evaluated thousands of earthquakes on Japan’s Noto Peninsula, located 190 miles northwest of Tokyo in the Sea of Japan. In 2021, after heavy snow, the rate of earthquakes in the region rose significantly – hundreds of records every day.
„They saw a factor-10 increase in the number of earthquakes in this region over what had happened before,” Frank said.
Biggest in the crowd A magnitude 7.5 earthquake struck on New Year’s Day This year. More than 240 deaths have been linked to this major shock event, According to the Japanese Red Cross.
According to Frank, the timing of the swarm is also unusual compared to the usual sequence of aftershocks.
„They have this statistical signature that the earthquakes are driven by something else,” he said.
He and other study authors compared the pattern of earthquakes on the Noto Peninsula with a pattern of pressure inside holes in the Earth’s surface. The model accounts for factors above ground that change the pressure beneath the bedrock — such as seasonal sea level changes, fluctuations in atmospheric pressure, and heavy rain or snow events.
The results indicated that the weight of snow cover on the Noto Peninsula increased the pressure in those holes. The researchers hypothesize that stress changes, such as adding and removing weight as ice accumulates and then melts, can disrupt pre-existing faults.
„If you have enough ice, you actually push the Earth down, and if you remove the ice, it rises back up,” Frank said.
Some previous research has suggested that environmental factors may play a role in initiating earthquakes. A 2019 studyShelley and his colleagues found that spring ice melt flowing in cracks in the earth near the caldera in the area around Mammoth Lakes, California, may have triggered a cluster of earthquakes.
Melting ice quickly recharged groundwater, and pressure changes triggered activity on relatively shallow faults. The researchers found that seismic activity in the region is historically 37 times higher during wet seasons than during dry seasons.
Research like this has fueled scientists’ interest in whether climate change could have a small effect on earthquake behavior.
„There are a number of studies that show a correlation in some cases between the timing of earthquakes and these processes at the surface,” Shelley said. „What I understand about climate change predictions is that there are more extreme weather, longer droughts and extreme wet periods. This could make these effects more pronounced.”
This article was originally published NBCNews.com