A 4.0 magnitude earthquake shook Memphis on Wednesday night just before 11 p.m.
It was the first significant earthquake felt by Memphians since a 5.2 magnitude in 2008.
Shelby Welch, a nursing student, said she was in her bedroom when the earthquake happened.
“I live by the train so at first I thought it was a train,” Welch, 19, said. “When I realized that there was no train sound, I figured it had to be an earthquake.”
It was the first time she had ever felt an earthquake. It just felt like the whole room was shaking, she said.
An earthquake happens when masses of rock shift below the Earth's surface and cause changes in pressure and seismic waves, according to National Geographic. The magnitudes of earthquakes are measured on seismographs. Most of the earthquakes that hit Memphis are 2 or 3 magnitude. The highest recorded earthquake was around a 5 on the seismograph. The 1842 and 1898 earthquakes were estimated to be at least a 6.0 magnitude. Since the technology did not exist to record them, they were estimated from damage caused and witness accounts.
Kent Moran has been working at the University of Memphis Center for Earthquake Research and Information as a historian for the past 16 years. He focuses mostly on studying the 1811-1812 earthquakes that shook what eventually became Memphis in the 1820s.
“The research facility at the U of M is partly school sponsored and partly state sponsored,” Moran said.
The center was opened in the 1970s as the Tennessee Earthquake Information Center. The purpose is to research historic earthquakes from Memphis and in the surrounding regions. New Madrid Seismic Zone is the main focus but they also study other seismic zones in the region, he said.
“This is the only regional earthquake facility,” Moran said. “There are other research places around, but they are more focused on states not the whole region.”
Earthquakes are a force of nature that can’t be predicted and may never be able to be predicted.
“Don’t look at the seasons,” Moran said. “Earthquakes come whenever they want to.”
Unlike weather, earthquakes can’t be predicted, he said. You can look outside and see the weather and prepare for what’s going to happen but with earthquakes it’s hard to prepare because they are so unexpected.
“That’s also a reason earthquakes cause so many fatalities,” Moran said.
The people that work at the CERI facility are professors and researchers as well as grad students. No one can do all the research by themselves, he said. The grad students are given a set of data and their job is to uncover everything they can. They may also work on projects given to them by their professors. Many of them will then use that as their dissertation.
“There is always something new to learn,” Moran said. “It never gets boring studying earthquakes. Research is always ongoing. Every time that you answer one question it uncovers more questions.”
The great 1811-1812 earthquakes have had 200 years to hide all their secrets, so it’s going to take time to try and answer all the questions, he said.
