When (and How Bad) Were the Worst Earthquakes Ever in Louisiana?
Who remembers our last earthquake? Off the top of your head, can you recall when the ground shook (if only a little), dishes rattled on the shelves and dogs barked (they always do)?
Uh...Earlier This Year
Well, it wasn't that long ago, actually. And it was in the Blanchard area. As KEEL reported in April of this year:
"There was an earthquake in our region while you were sleeping. The United States Geological Survey says the quake measured 3.1 on the Richter scale which is a very mild tremor. It happened at about 2:30 Thursday morning."
Sure, there seem to be more earthquakes than usual, say, over the past five years or so. But most experts chalk it up to minor shifts in the New Madrid Fault or even fracking.
Louisiana's Earthquake 'History'
But what about the history of earthquakes in our state. Is it possible that Louisiana, lying just south of that east to west major fault line, could someday experience an earthquake similar to California, much less hotspots like Indonesia or Haiti?
And it's not like we don't have (at least) a little history. Earthquakes have been documented in Louisiana since the early 1800s. Some major quakes that originated in places as far away as Missouri and South Carolina have been felt here, particularly across the ArkLaTex.
According to records, the largest Louisiana earthquake happened in 1930 in Napoleonville (Assumption Parish). That quake measured 4.2 on the Richter Scale, and, as the old newspapers phrased it, "damaged buildings and broke windows at Napoleonville and cracked plaster at White Castle, northwest of Napoleonville. Many people in the area rushed into the streets."
And there are stories of quakes of a not so recent vintage. Louisiana has felt tremors from major disturbances, though not for more than two centuries. A number of devastating earthquakes rattled the central US in 1811 and 1812. These quakes were some of the largest ever experienced in America and the effects were felt, not only across this part of the state, but and all the way to the south Louisiana, even New Orleans.
All told, since 1843, the US Geological Survey reports that more than 40 earthquakes felt in or around Louisiana.
And LSU Scientists Say...
And the conclusion? Well, here's researchers Donald Stevenson and Richard McCullah at lsu.edu have to say:
"Although Louisiana is not seismically active, it is evident from the historical record that small earthquakes occasionally do occur here. The New Madrid seismic zone is the area most likely to produce earthquakes that could affect Louisiana. Other more immediate geologic faulting hazards in Louisiana are associated with growth faults, located primarily in the southern portion of the state. These faults pose a threat more to property than life."
So, despite a lengthy earthquake history, Louisiana has relatively little destructive seismic activity on record, and to us, that seems okay. As any Louisianan will tell you, the annual threats of tornadoes and hurricanes are more than enough to worry about.