Observations of Epicentral Infrasound From Shallow Low-Magnitude Earthquakes in the Permian Basin, West Texas
Seismic waves emanating from earthquakes and underground explosions can disturb the Earth/atmosphere interface and generate acoustic waves that may propagate to local and even global distances. Epicentral infrasound (EIS) is generated directly above an event while local infrasound (LIS) is generated at or near a receiver. Both have been observed at distances of hundreds to thousands of km following explosions and moderate to large earthquakes (ML 3.55 and greater). Proximal (<50 km) observations, however, are especially important for characterizing low-energy events. LIS has been observed for an earthquake as small as Mw 1.87. While laterally propagating EIS has been observed within 10 km of buried chemical explosions, to our knowledge there are currently no observations of EIS at such distances following earthquakes of any magnitude. The Pecos Infrasound Network observational campaign, during which infrasound was recorded on three arrays during a period of high seismic activity in the Permian Basin of West Texas, was designed to remedy this lack of observations. From January to June 2023, nearly 1000 earthquakes (1.2 ≤ ML ≤ 4.2) occurred within 50 km of the network, all at depths <11 km. We analyzed 191 ML ≥ 2.5 events and identify coherent infrasound signals following 45 earthquakes. We highlight exemplary infrasound signals following three events. All three earthquakes generated LIS at or near the receivers. Two of the three (both ML 2.9) also generated laterally-propagating EIS detected on an array about 3 km away, which is confirmed with array processing methods and comparison with seismic observations. To our knowledge, these are the first observations of laterally-propagating EIS at proximal ranges following an earthquake of any magnitude.
SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
Session: Advancements in Forensic Seismology and Explosion Monitoring [Poster Session]
Type: Poster
Room: Exhibit Hall
Date: 5/2/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Loring Schaible
Student Presenter: No
Additional Authors
Loring Schaible Presenting Author Corresponding Author dpschai@sandia.gov Sandia National Laboratories |
Fransiska Dannemann Dugick fkdanne@sandia.gov Sandia National Laboratories |
Daniel Bowman dbowma@sandia.gov Sandia National Laboratories |
Alexandros Savvaidis alexandros.savvaidis@beg.utexas.edu University of Texas at Austin |
Cooper McCabe cooper.mccabe@beg.utexas.edu University of Texas at Austin |
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Observations of Epicentral Infrasound From Shallow Low-Magnitude Earthquakes in the Permian Basin, West Texas
Category
Advancements in Forensic Seismology and Explosion Monitoring
Description