TexNet: A Statewide Seismological Network in Texas

Induced seismic events have been recorded recently in the southern midcontinent of the United States, including Texas. These events, associated with hydrocarbon exploration and the subsequent disposal of wastewater byproduct, have led to substantial public discussion regarding cause, public safety, and potential risks of damage to infrastructure. In an effort to better understand these events and to monitor earthquake activity in general, the 84th Texas Legislature funded creation of a statewide, seismic-monitoring program known as the Texas Seismological Network (TexNet). The goal of TexNet is to provide authenticated data to evaluate the location, frequency, and likely causes of natural and induced earthquakes, so TexNet, through August 2018, deployed 58 new broadband seismic stations in the state of Texas. Of these, 25 are permanent and form, along with 18 existing broadband stations, an evenly spaced backbone, seismic network in the state. In addition to the permanent installations, 33 of the new stations are portable and have been deployed in four different areas of the state experiencing recent seismicity and having high-socioeconomic importance. An earthquake-management system (SeisComp3) is being used to detect, locate, and analyze earthquake events and earthquakes measuring M-L 2 and above have been made available through various dissemination tools by the next working day. Depending on daily earthquake rate, events of magnitude down to 1.5 are publicly available in three business days from the time they are detected. The initial implementation of TexNet has reduced the magnitude of completeness (M-c) across Texas from 2.7 to less than 1.5 in specific areas and has played a role in a large decrease in uncertainties about earthquake-source parameters. Supplemental Content: Tables listing the borehole stations site assessment and installation and the P- and S-wave velocities of the Earth model used for earthquake location in the Delaware basin are presented, and noise analysis of sites visited for deployment of a permanent station, classification of noise levels for Texas Seismological Network (TexNet) stations, a worldwide map where SeisComP3 (SCP3) installations in 2018, and a list of seismological observatories that SCP3 used.