A burst of seismic activity shook northwest Louisiana early Monday when four earthquakes struck within a 10-minute window near the small village of Edgefield, intensifying concerns in a region that has seen unusual tremors in recent weeks.
The United States Geological Survey confirmed the sequence occurred between 4:33 a.m. and 4:41 a.m. CT on March 9, with magnitudes ranging from 3.1 to 4.0 (initially reported as up to 4.4 for the strongest after review). All quakes were shallow, at depths around 3 miles, and clustered tightly within a few miles of each other northwest and northeast of Edgefield in Red River Parish.
The events follow a magnitude 4.9 earthquake on March 5 near Coushatta — about 10 miles southeast — that ranks as the strongest inland quake in Louisiana’s recorded history and the second-largest overall in the state behind a 5.3 offshore event in 2006. That March 5 tremor was felt across the ArkLaTex region, including Shreveport, parts of Texas and Arkansas, waking residents and rattling homes for up to 10 seconds.
USGS geophysicists classify the March 9 cluster as aftershocks linked to the larger March 5 mainshock. William Barnhart, a USGS seismologist, told local media that additional aftershocks remain possible as the fault system adjusts. Monitoring teams have deployed extra seismic instruments in Red River Parish to better track the sequence and gather data on subsurface structures.
Residents in Edgefield, Coushatta and surrounding rural areas reported feeling the shaking vividly. “It was like a big truck drove by, but then it kept going and another one hit,” said one Edgefield homeowner interviewed by KSLA News. No immediate reports of major damage or injuries emerged from the March 9 quakes, though minor items fell from shelves and some residents described brief power flickers. The area, largely agricultural with scattered homes, experienced light to moderate intensity shaking according to USGS “Did You Feel It?” citizen reports.
The four confirmed events unfolded as follows, per USGS data:
– Magnitude 3.1 at 4:33 a.m., about 2.5 miles northwest of Edgefield, depth 3.1 miles.
– Magnitude 3.1 at 4:34 a.m., less than 2 miles north-northeast of Edgefield, similar depth.
– Magnitude 3.9 at 4:40 a.m., roughly 3 miles northeast of Edgefield.
– Magnitude 4.0 (upgraded from initial 4.4 estimate in some reports) at 4:41 a.m., 4.9 miles northwest of Edgefield, depth approximately 3.1 miles.
This swarm marks part of a broader uptick in seismic activity in northwest Louisiana. Since December 2024, the region has recorded at least 16 events of magnitude 1.5 or greater, with the March sequence pushing totals higher. Seismologists note the area sits near the northern edge of the Gulf Coast sedimentary basin, where faults are typically inactive compared to California or the New Madrid zone. The recent activity has surprised experts, prompting discussions about potential triggers.
Possible causes under investigation include natural tectonic stress release along minor faults or induced seismicity linked to industrial activity. Louisiana has seen increased oil and gas operations, including wastewater injection in nearby states like Oklahoma and Texas, which have triggered swarms in the past. While no direct link has been confirmed here, researchers say the shallow depths and tight clustering warrant closer scrutiny. A USGS team continues fieldwork, with preliminary findings expected by early summer.
The March 5 magnitude 4.9 event — centered at 32.038°N, 93.415°W, depth 11.1 km — was widely felt, with reports from as far as central Louisiana and southern Arkansas. It prompted the highest number of “Did You Feel It?” submissions in state history. Probabilities posted by USGS indicate a 72% chance of magnitude 3+ aftershocks following that mainshock, 16% for magnitude 4+, and low odds for stronger events.
Local emergency officials urged calm while advising residents to prepare basic earthquake safety measures: drop, cover and hold on during shaking; secure heavy furniture; and keep an emergency kit ready. No tsunami risk exists given the inland location, and no structural collapses were reported from any recent quakes.
The string of tremors has heightened awareness in a state rarely associated with earthquakes. Historical records show Louisiana experiences infrequent, low-magnitude events, mostly offshore or near the Mississippi River delta due to sediment loading. The current inland swarm near Red River Parish stands out as anomalous.
As of March 11, no additional significant quakes have followed the March 9 cluster, though minor aftershocks below magnitude 2.5 continue to register on sensitive instruments. USGS continues to update its interactive map and encourages public reporting to refine models.
For many in the ArkLaTex, the back-to-back sequences serve as a reminder of the Earth’s unpredictability even in stable regions. While experts stress the events remain minor on a global scale, the frequency has residents watching closely for any escalation.
