SAN ANTONIO - There is speculation that fracking being done by the oil companies in the area could have contributed, if not caused, Thursday’s 4.8 magnitude earthquake that struck 76 miles south-southeast of San Antonio.
Local geologist John Long was at work on the eleventh floor of the Frost Bank Building along Northeast Loop 410. He actually felt the earthquake from his office. Within minutes he had a good idea of what caused the earth to shake.
Long works for Osborn Heirs, a local compnay that specializes in oil and gas exploration and development.
“I usually get here early. At about 7:24 I noticed that the blinds, we have metal blinds here, they started shaking and rattling -- and I did feel a slight sway in the room," recalled Long.
The earthquake only lasted a few seconds.
"I looked on the map and it turns out it's right in the middle of an existing oil field, Fashing Field, which has had earthquakes over the last 40 or 50 years,” explained Long.
According to Long, the oil field has been around since the mid 1950's. A lot of drilling has gone on since then, and coincidentally, there have been a handful of earthquakes over the years.
“Starting in 1973 it had an earthquake that registered at a 3.0, and then in 1984 it had an earthquake that registered about 3.5 or so,” said Long.
In Long’s expert opinion, it's very possible the earthquake is a result of the disposal of fracking fluids.
“I know the previous earthquakes were tied almost without a doubt with drawing fluids out of the ground, and I’m not sure how much fluid is being withdrawn from that field right now, but they are injecting fluid into the ground with these frack jobs,” added Long.
All this is being done over a fault that has mostly been inactive, but with the recent boom of fracking in the area Long says it appears the fault was forced to awaken and caused a shake up.
“Anytime you take fluid or add fluid to the earth in this particular area it seems as if it leads to earthquakes,” said Long.