A 3.0 magnitude earthquake struck Texas Monday morning.
The quake was recorded less than 50 miles south of San Antonio around 10:50 am ET.
According to the US Geological Survey (USGS), the earthquake took place in Wilson County, which is at the southern tip of the greater San Antonio metro area.
As of 2024, San Antonio had a population of just under 1.5 million people.
The entire San Antonio-New Braunfels metropolitan area, which Wilson County is a part of, is home to 2.6 million people, according to the last census in 2020.
It’s been a rough start to 2025 for San Antonio, which has experienced multiple earthquakes in recent months – which have been a rare event in the area until now.
On January 29, a near-historic magnitude 4.5 earthquake was felt in the city, followed by a 3.6 tremor two days later.
The 4.5 earthquake was the third-strongest quake in South Texas history – behind a 4.8 magnitude earthquake in 2011 and a 4.7 quake in February 2024.
Monday’s magnitude 3.0 earthquake struck just south of San Antonio, Texas which is home to 1.5 million residents
The gulf-margin normal faults runs through southern and eastern Texas and extends into the Gulf of Mexico – now referred to as the Gulf of America
As for Monday morning’s 3.0 quake, seismic activity above 2.5 in magnitude can often be felt and cause minor damage.
USGS notes that the latest earthquake in South Texas took place right along the gulf-margin normal faults.
The faults are large cracks in the Earth’s crust that form along the edge of the Gulf of Mexico Basin – now being referred to as the Gulf of America by the US government.
These faults run straight through southern Texas and occur because the land near the Gulf is gradually stretching and sinking due to gravity, the weight of thick sediment layers, and movement deep within the Earth.
Previously, the US Nuclear Regulatory Commission said that the gulf-margin normal faults has a low risk of generating seismic activity in Texas.
The vast majority of earthquakes result from the constant movement of tectonic plates, which are massive, solid slabs of rock that make up the planetary surface and shift around on top of Earth’s mantle — the inner layer between the crust and core.
As the tectonic plates slowly move against each other, their edges can get stuck due to friction and stress will build along the edges.
When that stress overcomes the friction, the plates slip, causing a release of energy that ravels in waves through the Earth’s crust and generates the shaking we feel at the surface.
Around the world, earthquakes between magnitude 2.5 and 5.4 are quite common, striking around 500,000 times each year.
On January 29, a near-historic magnitude 4.5 earthquake was felt in the city, followed by a 3.6 tremor two days later
In general, Texas is not very seismically active because it’s not situated near tectonic plate boundaries, though some regions see more earthquakes than others due to the presence of fault lines, which are naturally-occurring fractures in the Earth’s crust.
In recent years, however, research has shown that human activity — specifically oil and gas drilling — is making the state’s seismic events more frequent and intense.
Experts have not confirmed whether the magnitude 4.5 Falls City earthquake was linked to fracking, but this city is located in the Eagle Ford Shale area which is known for oil and gas production.
Texas is the biggest producer of crude oil and natural gas in the US, based on an assessment of 2023 data by the US Energy Information Administration.
The state is known for its extensive use of fracking, or the process of extracting oil and gas from deep underground by blasting large quantities of water, chemicals and sand into rock formations to crack them open and release the fuels trapped inside.
Fracking is not usually the direct cause of an earthquake. It is actually the process of disposing wastewater produced through fracking that can trigger tremors.
This wastewater is injected into disposal wells that typically operate for longer periods of time and receive much more fluid than is injected into the ground during the fracking process, making them more likely to produce earthquakes, according to the USGS.
