Accuracy and Uncertainty of TexNet Absolute Seismic Event Location in West Texas
Date: 4/24/2019
Time: 08:45 AM
Room: Cascade I
Likely induced seismicity has been recorded in the central U.S., including in Texas. This seismicity, possibly associated with hydrocarbon production and associated wastewater disposal, has led to substantial public discussion regarding cause, public safety, and potential infrastructure damage. To monitor this seismic activity the 84th Texas Legislature funded the statewide, Texas Seismological Network (TexNet).
High accuracy and realistic uncertainty estimates for absolute location of seismic events is critical to TexNet monitoring, especially when seismic sources must be associated with known locations of human activity. Error in absolute location has many causes, including error in the seismic velocity model used for calculating travel-times, error or mis-identification of phase onset picks, and inadequacies of the network station geometry.
Here we consider absolute location accuracy and uncertainty estimates for TexNet monitoring of the West Texas area around Pecos, Texas. We seek to improve absolute location accuracy considering: use of realistic 3D models, robust location algorithms, additional stations, and station travel-time corrections. We investigate location uncertainty estimates through mapping and assessment of spatial location error considering: picking errors, network geometry, different station sub-sets and velocity models, and station travel-time corrections. Additionally, in the absence of accurate ground-truth events, we probabilistically associate the seismicity with hydraulic fracturing space-time information to generate pseudo ground-truth station corrections and we examine their effect on absolute locations.
Presenting Author: Anthony Lomax
Authors
Anthony Lomax anthony@alomax.net ALomax Scientific, Mouans-Sartoux, , France Presenting Author
Corresponding Author
|
Alexandros Savvaidis alexandros.savvaidis@beg.utexas.edu University of Texas at Austin, Austin, Texas, United States |
Accuracy and Uncertainty of TexNet Absolute Seismic Event Location in West Texas
Category
From Drifting to Anchored: Advances in Improving Absolute Hypocenter Location Accuracy for Natural, Induced and Explosion Seismic Events