Underground volcano sends seismic ripples
Tremors felt throughout the Delta were caused by a magnitude 3.7 earthquake, which was recorded by the U.S. Geological Survey, 5 miles from Hollandale at 4:26 p.m. Tuesday, Jan. 8, 2019.
Signs point to a volcano buried beneath the Delta as the cause of the earthquake, according to information supplied by David Dockery, Mississippi Department of Environmental Quality, state geologist and author of “The Geology of Mississippi.”
The region is home to at least five buried volcanoes: The Epps Dome in northwestern Louisiana; Cary, Midnight, and Panther Domes under the southern Mississippi River Delta; and Jackson Dome under Mississippi’s capitol city.
The epicenter of the earthquake was located on the north flank of what geologists in Mississippi have named the Panther Burn Dome, a large Paleozoic horst block that has moved periodically since its suspected origin in the late Permian Period approximately 270 million years ago. The block’s most prominent upward structural movement occurred during Late Cretaceous period approximately 66 million years ago, roughly one million years before the extinction of dinosaurs.
Information came to Dockery Wednesday via a former student, whom is a petroleum exploration specialist. According to Dockery’s source, “The earthquake is located and, in my opinion, unquestionably associated with fault movement atop the Panther Burn Dome.”
The Panther Burn Dome is oval-shaped, oriented northwest/southeast along its axis, and is similar in size to the adjoining Lake Washington Dome in Washington County, as well as the Cary Dome located to the south in Sharkey County. It is one of six similar Paleozoic-aged upward moving blocks that have been identified in the subsurface of west-central Mississippi and northeast Louisiana.
Tuesday’s quake was likely caused by very minor movement along a fault that formed when the Panther Burn Dome was first uplifted and a horst block was created atop the dome.
“The initial explanation for the earthquake changed from a grabin, or a down-dropped block, to a horst, or an up-thrown block, and from a syncline to a buried volcano,” Dockery said.
Dockery’s initial assessment of the earthquake was made using data from Louis Lyell, a hobbiest who owns a seismograph and supplies data he collects to Dockery.
“There are more refined instruments in the state not under my control and in which the data is collected but perhaps not processed in a timely manner,” Dockery said.
“Mr. Lyell is prompt to send me his seismogram so I use it.”
Dockery said there have been comparable quakes in the Delta’s past.
On Dec. 16, 1931, a magnitude 4.7 earthquake shook the Batesville/Charleston area. Two earthquakes rocked Greenville in June 1967. A magnitude 3.8 quake on June 4 and a magnitude 3.4 on June 29. More recently in Sunflower County, a magnitude 3.5 earthquake occurred Jan. 8, 1973, but was not reported to have been felt by residents leading Dockery to believe this one must have occurred much deeper in the Earth.
Officials respond: preparedness is key
Washington County Emergency Management and Sheriff’s Department responded immediately to Tuesday’s quake by quelling fears and assessing potential damages.
“The first thing I did was go outside to make sure nothing blew up and got on USGS website, and honestly for being a federal shutdown, they got it up with within five minutes,” said David Burford, Washington County director of Emergency Management.
“We sent some deputies out to work within a couple of square miles of the location – checked it out, just in case, for gas, fires and to calm folks down.”
Burford said that no damage has been seen or is expected from the earthquake, but that Washington County needs to have measures in place to combat potentially more dangerous quakes that could occur in the future.
“We’ve been pushing and talking about quakes, but no one seems to take it seriously,” Burford said.
“We take an all-hazard approach that covers pretty much everything other than serious things that would affect transportation.”
Washington County Sheriff Billy Barber dispatched more than a dozen deputies to assess damages and potential injures.
“We took a solemn oath to preserve peace, property and life,” Barber said.
“Our biggest task was to assure citizens that everything was okay and prevent panic.”
Barber said that he was grateful that no casualties or damages were reported, but urged citizens to remain vigilant and to be prepared for any sort of crisis.
“We know that we live in an area that has been identified as a potential earthquake zone; therefore, always have a disaster plan and keep supplies on hand in case of emergencies,” Barber said.
“Know that we are hard at work to ensure that we are prepared for any instance – any crisis.”
Schools near the site of the earthquake experienced tremors, as well.
“The whole building shook – for seconds. Although no damages to facilities have been discovered yet, we’re on the lookout for any issues that may arise in the aftermath of the earthquake,” said Lawrence Hudson, superintendent of Western Line School District.
“Earthquake drills are a part of our crisis management plan, although they aren’t practiced as much as more common drills like fire or tornado,” he continued. “Yesterday’s quake, however, served as a reminder that these drills are just as important to rehearse to ensure the safety of our staff and students.”
John Jehab Benson
“I was playing a board game with my son and it felt like the floor moved then a couple seconds later it moved again felt like a big truck gently bumped our house.”
Freda Marie Arinder
“[In]Greenville [it] felt like a explosion.”
“[I was in]Hollandale at a relative's house. I accused my 3 boys of misbehaving and shaking a brick house, lol.”
Roxanne Mosley Pardon
“I felt it in Avon! I didn’t think my house would ever stop shaking! No damage just pictures and baskets shifted some. My nerves are still on edge!”
Rosie L. Thomas
“[In] Greenville. I thought someone ran into my house with their car.”
“At Greenville Animal Clinic we thought someone had run into the building!”
Valerie Guyton Clyde
“[I was in] Hollandale at home. I thought a semi crashed into my house.”
Amanda Goodwin Musgrove
“I was at work in Wayside and I thought the ceiling was falling in on me. Everything was shaking like crazy for about 5 seconds it seemed. I was shaken up for a while afterwards.”
Veronica Michelle Gearring
“[I was] at GHEC, it felt like someone crashed into the building.”
Olivia Dell Billings Kline
“I felt it at L&W Fish Farm Road really bad shook my trailer so bad I thought it was going to fall off its blocks.”