Posted by
okgeosurvey on
July 25, 2019
“What is that?” asked Dr. Walter, pointing to the seismograms displayed on a flat screen TV hanging on the wall of the OGS seismic lab. There were a series of red marks that indicate automatic picks by the computer as potential earthquakes. However, these marks were spaced very regularly, so regularly that at first glance they looked like some sort of mechanical noise. The problem with that assumption was that they were showing up on stations all across the state, all at the same time. Anything that widespread is usually associated with a correspondingly large scale event, like an earthquake. This pattern we were seeing looked nothing like an earthquake, or even a series of earthquakes. Other potential causes we guessed at were military aircraft, meteor shower, or something related to gas pipelines. We dubbed this acoustic pattern ‘The Anomaly.’
This .gif is a map showing the locations of stations in the sequence they detected the anomaly. Note that this does not portray the actual arrival time duration (which would be spanning over nine minutes and be at irregular intervals).
Curious about what we were seeing, and what our sensors were hearing, we attempted to locate a potential source for individual pulses from the pattern. This produced nothing but garbage location potentials with errors so high it was useless. We also attempted locating a source using the first arrival time of the pattern at various stations where it was clearly discernible. This yielded a more interesting result. It still failed to yield a location, however, by plotting out the first arrival times on a map, the anomaly arrived in a ‘ping pong’ like pattern back and forth across the state, mainly in a swath from Tulsa, across OKC and toward Lawton.
We contacted the Oklahoma Corporation Commission about the anomaly, and inquired if they had received any reports of strange noises. Yes, in fact, they had received reports, and had even sent personnel to investigate some of the reports. However, they are as much in the dark as to a potential cause as we are. Contacting Tinker AFB, Vance AFB, and Altus AFB also didn’t lead to any answers.
The precision of timing in the pattern and regularity of its timing most days suggest that it is associated with some sort of widespread activity in the state that has recently been implemented (since March 15th). Also, over time it is occurring more regularly and more strongly (becoming more widespread). As for an exact cause, however, we’re still just guessing.
