How snow and rain might trigger earthquakes

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Scientists have long understood that earthquakes generally occur due to the movement of the earth’s plates beneath the surface.

However, a new study from MIT has introduced a surprising twist: weather events like heavy snowfall and rain might also influence when and how earthquakes happen.

Published in Science Advances, this research highlights a connection between climate and earthquakes, particularly through a recent study of seismic activity in northern Japan’s Noto Peninsula.

This area has experienced what scientists call an “earthquake swarm” – a series of ongoing tremors without a clear beginning main shock.

What’s intriguing is that these swarms seem to be linked with seasonal weather patterns.

William Frank, an assistant professor at MIT and one of the study’s authors, explains that the weight from heavy snowfall or rain can change the underground pressure, affecting how the earth moves.

This is because the added weight increases the pressure in the underground fluids found in the earth’s cracks, which can then trigger movements that lead to earthquakes.

To investigate this theory, the research team looked at over a decade of earthquake data from the Noto Peninsula, alongside detailed meteorological data. They noticed that the timing of the earthquakes correlated with periods of intense precipitation, especially heavy snowfall.

Using a sophisticated model, the researchers simulated how these environmental changes could impact underground pressures over the last eleven years.

They found that the changes in underground pressures matched up very closely with the shifts in how fast seismic waves traveled through the area, which is influenced by the earth’s underground structure.

Especially significant was the finding that extreme snowfall events had a strong connection to when earthquakes occurred. The model showed that these periods of heavy snow matched up very well with the timing of the earthquake swarms.

The study suggests that as the climate changes, and extreme weather events like heavy snowfall become more common, we might see more frequent or intense earthquakes in certain regions. This connection between weather and earthquakes isn’t just limited to Japan; it could potentially apply to other parts of the world as well.

While the movements of tectonic plates will always be the primary cause of earthquakes, this research shows that climate and weather can also play a critical role. It opens up new possibilities for understanding and predicting when earthquakes might occur, particularly in regions prone to heavy seasonal precipitation.

This finding is crucial as it not only helps scientists better understand the complex dynamics of earthquakes but also suggests that future climate changes could have broader impacts on the earth’s geological activities. The research, supported by the National Science Foundation, is a step forward in unraveling the intricate ways our planet functions.