Overview of Sunday's Earthquake:
The 5.1 magnitude earthquake that struck near Sparta, NC on Sunday morning has left a lot more questions than fear. Here are answers to some of the most frequently asked questions:
What causes earthquakes?
An earthquake occurs when you have a sudden slip on a fault. This has to do with two tectonic plates getting stuck together due to friction. However, when the two tectonic plates overcome that friction and shoot away from one another, the stored energy is also released.
This energy is what we call the seismic waves that are transmitted from fault to fault, leading to the shaking of the Earth's surface.
What are foreshocks and aftershocks?
Foreshocks are the smaller earthquakes before the big earthquake. There were 8 smaller earthquakes just a day before the big 5.1 magnitude earthquake near Sparta, NC on Sunday. Think about it as a workout. Before getting into the actual workout, you have to get your body ready with a warm up. Foreshocks are basically the warm up for the big earthquake.
Aftershocks are smaller earthquakes that happen after the big earthquake. Think of these as the cool down portion of your workout. When you are getting your body readjusted after a tough work out. Aftershocks are just the Earth's readjustment along the portion of the fault that slipped.
For more on these foreshocks and aftershocks, click here. The United States Geological Survey (USGS) has excellent answers.
Why are earthquakes felt at greater distances across the Eastern United States and felt at lower distances across the Western United States?
There are simply less faults across the Eastern United States, which of course leads to less earthquakes, but it also means waves of energy are able to transmit over greater distances. This is mainly because there are less faults to break up the transmission of the seismic waves.
Across the Western United States, there are many more faults. This not only leads to more earthquakes, but it causes seismic waves to be broken up much more across many faults, leading to less transmission of the seismic waves.
Are earthquakes rare across our area?
This is shocking for many, but earthquakes are not rare across our area, we have actually seen over 1000 earthquakes across the Eastern United States in the last 20 years. Over 20,000 earthquakes actually occur each year. But the earthquakes that do occur across are area are usually weaker earthquakes. The rare thing about Sunday's earthquake was the strength of it.
North Carolina has not seen an earthquake that strong in over 100 years. Virginia actually had a 5.8 magnitude earthquake in Lousia County, Va on August 23rd, 2011.
This earthquake was also felt by residents for thousands of miles away from the epicenter. So if we encounter another earthquake over the next few years. Do not be shocked.
How do I get to safety during an earthquake?
The truth is, earthquakes are probably one of the hardest natural distastes to protect yourself from. Mainly because they are hard to predict. The National Weather Service can issue a tornado warning for your area, which helps you know to get to safety for the chance of a tornado.
However, there is no such thing as an earthquake warning. Although, foreshocks ahead of an earthquake could help indicate a bigger earthquake that is on the way. Earthquakes can also trigger tsunamis, which can be warned for coastal cities.
When shaking begins during an earthquake, you really just want to protect your head from any falling objects or debris. For more information on staying safe during an earthquake, click here.