5.1mag earthquake shakes awake portions of the East Coast

This morning a 5.1mag earthquake near Sparta, North Carolina shook some folks awake. The quake occurred around 8am Eastern time.

Courtesy: USGS

The USGS tweeted: “The August 9th, 2020 M 5.1 earthquake near Sparta, North Carolina, occurred as a result of oblique-reverse faulting in the upper crust of the North American plate.”

People reported feeling the quake up to 1,000 miles away.

Screen Shot 2020-08-09 at 10.11.02 AM
Courtesy: USGS

In fact, there were even a few reports of people feeling it in Mississippi.

Screen Shot 2020-08-09 at 10.09.23 AM
Courtesy: USGS

That said, at this distance it would feel no different than, say, a dump truck driving by outside your house.Perhaps not even that.




In North Carolina, the USGS says be on the lookout for potential aftershocks.

Be ready for more earthquakes

More earthquakes than usual (called aftershocks) will continue to occur near the mainshock.
When there are more earthquakes, the chance of a large earthquake is greater which means that the chance of damage is greater.
The USGS advises everyone to be aware of the possibility of aftershocks, especially when in or around vulnerable structures such as unreinforced masonry buildings.
This earthquake could be part of a sequence. An earthquake sequence may have larger and potentially damaging earthquakes in the future, so remember to: Drop, Cover, and Hold on.

What we think will happen next

According to our forecast, over the next 1 Week there is a 4 % chance of one or more aftershocks that are larger than magnitude 5.1. It is likely that there will be smaller earthquakes over the next 1 Week, with 0 to 54 magnitude 3 or higher aftershocks. Magnitude 3 and above are large enough to be felt near the epicenter. The number of aftershocks will drop off over time, but a large aftershock can increase the numbers again, temporarily.

More details about the earthquake forecast are provided in the section “Our detailed aftershock forecast” below.

About this earthquake and related aftershocks

So far in this sequence there have been 0 magnitude 3 or higher earthquakes, which are strong enough to be felt, and 0 magnitude 5 or higher earthquakes, which are large enough to do damage.

Our detailed aftershock forecast

The USGS estimates the chance of more aftershocks as follows: Within the next 1 Week until 2020-08-16 14:10:00 (UTC):

The chance of an earthquake of magnitude 3 or higher is 56 %, and it is most likely that as few as 0 or as many as 54 such earthquakes may occur in the case that the sequence is re-invigorated by a larger aftershock.

The chance of an earthquake of magnitude 5 or higher is 5 %, and it is most likely that as few as 0 or as many as 2 such earthquakes may occur.
The chance of an earthquake of magnitude 6 or higher is 1 in 200, such an earthquake is possible but with a low probability.
The chance of an earthquake of magnitude 7 or higher is 1 in 2,000, such an earthquake is possible but with a low probability.

About our earthquake forecasts

No one can predict the exact time or place of any earthquake, including aftershocks. Our earthquake forecasts give us an understanding of the chances of having more earthquakes within a given time period in the affected area. We calculate this earthquake forecast using a statistical analysis based on past earthquakes.

Our forecast changes as time passes due to decline in the frequency of aftershocks, larger aftershocks that may trigger further earthquakes, and changes in forecast modeling based on the data collected for this earthquake sequence.

You may be asking yourself, “How was an earthquake felt so far away?

Over on the East Coast, the rocks are a lot older than rocks on the West Coast. Because of that, the rocks are more brittle on the East Coast than on the West Coast. And pressure waves from earthquakes travel easier through those kinds of rocks. So an earthquake can be felt at a much greater distance!



Author of the article:


Nick Lilja

Nick is former television meteorologist with stints in Amarillo and Hattiesburg. During his time in Hattiesburg, he was also an adjunct professor at the University of Southern Mississippi. He is a graduate of both Oregon State and Syracuse University that now calls Houston home. Now that he is retired from TV, he maintains this blog in his spare time.