Summary of the North Texas Earthquake Study seismic networks, 2013-2018

From 2013 to 2018, local seismic research networks operated by Southern Methodist University (SMU) have provided basic earthquake data needed to assess seismic hazard and to address the cause of the increased seismicity rates in the Fort Worth basin (FWB) and Dallas-Fort Worth metropolitan area, an area that was aseismic until 2008. This article summarizes the configuration, operation, and capability of the SMU FWB networks and documents how network geometries evolved in response to the onset of new earthquake sequences with instrumentation and funding availability constantly in flux. Network design strategies focused on providing accurate hypocenter and focal mechanism information while still constrained by the realities of dense urban environment operations. The networks include short-period single- and three-component sensors, broadband to intermediate period velocity sensors, and accelerometers. We document the complex metadata associated with the telemetered local seismic networks and provide necessary insights into temporal and spatial changes made to the networks from 2013 to 2018. The rich datasets contain local and regional earthquakes, anthropogenic and ambient noise, quarry blasts, and weather events. Prior publications document a causal link between earthquakes in the FWB and wastewater disposal and/or production activities associated with shale gas extraction, and the continuous waveform data described here allow for significant breakthroughs in understanding the physical mechanisms leading to induced earthquakes.