Aftershocks follow large earthquakes — sometimes for weeks, other times for decades. But in the U.S., some areas may be experiencing shocks from centuries-old events.
In the 1800s, some of the strongest earthquakes in recorded U.S. history struck North America’s continental interior. Almost two centuries later, the central and eastern United States may still be experiencing aftershocks from those events, a new study finds.
When an earthquake strikes, smaller quakes known as aftershocks can continue to shake the area for days to years after the original earthquake occurred. These smaller quakes decrease over time and are part of the fault’s readjustment process following the original quake. While aftershocks are smaller in magnitude than the main shock, they can still damage infrastructure and impede recovery from the original earthquake.
“Some scientists suppose that contemporary seismicity in parts of stable North America are aftershocks, and other scientists think it’s mostly background seismicity,” said Yuxuan Chen, a geoscientist at Wuhan University and lead author of the study. “We wanted to view this from another angle using a statistical method.”
Read more at American Geophysical Union
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