What Is Happening at the New Madrid Seismic Zone?

By Alice Nichols

The New Madrid Seismic Zone (NMSZ) is a region in the central United States that has been experiencing significant seismic activity. The NMSZ is named after the town of New Madrid, Missouri, which was the site of the largest earthquake sequence to ever occur in the contiguous United States. This earthquake sequence took place in 1811-1812 and included four major earthquakes with magnitudes estimated to be between 7.0-8.0 on the Richter scale.

Since then, the NMSZ has been relatively quiet, with only small earthquakes occurring sporadically over the years. However, recent seismic data has shown an increase in earthquake activity in this region.

According to scientists at the United States Geological Survey (USGS), there have been over 200 small earthquakes detected in the NMSZ since the beginning of 2020. These earthquakes are not large enough to cause significant damage, but they are a cause for concern as they indicate that there is increased pressure building up in the region.

One theory as to why this increase in seismic activity is occurring is due to changes in groundwater levels and flow patterns. The NMSZ sits atop a series of faults that were created by ancient geological events, and these faults are still active today. As groundwater levels change due to factors such as drought or heavy rainfall, it can alter the stress on these faults and lead to increased seismic activity.

Another theory is that this increase in seismic activity could be a precursor to a larger earthquake event. The USGS estimates that there is a 25-40% chance of a magnitude 6 or greater earthquake occurring within the NMSZ within the next 50 years.

Despite these concerns, it’s important to note that earthquakes are unpredictable and difficult to forecast accurately. However, scientists continue to closely monitor seismic activity in this region and work towards better understanding how and why earthquakes occur.

In conclusion, while it’s impossible to predict exactly what will happen at the New Madrid Seismic Zone, the increase in seismic activity is certainly cause for concern. It’s important for individuals living in this region to be prepared for the possibility of earthquakes and to have an emergency plan in place.