DOI: 10.5061/dryad.g1jwstr03
title: Data from: Proximal observations of epicentral infrasound generated by shallow low‐magnitude earthquakes in the Permian Basin, West Texas

description: Infrasound generated by earthquakes and explosions is generally detected
 at receivers at epicentral distances of hundreds to thousands of
 kilometers. However, proximal (&lt;50 km) observations are especially
 important for low‐magnitude earthquakes and low‐yield explosions that may
 not generate signals capable of being detected at great ranges. Here, we
 present on the signals detected on an infrasound array 3 km away from two
 ML 2.9 earthquakes in the Permian Basin of west Texas. Local infrasound
 (LIS), generated at receivers during the passage of seismic waves, was
 detected following each earthquake. Epicentral infrasound (EIS), created
 at or near the epicenter and propagating away as a sound wave, was also
 detected. Array processing methods show that the EIS signals arrive from
 the same direction as the earthquake epicenters and at acoustic speeds. To
 our knowledge, these are the first observations of laterally propagating
 EIS at proximal ranges following an earthquake of any magnitude.
description: # Data from: Proximal observations of epicentral infrasound generated by
 shallow low‐magnitude earthquakes in the Permian Basin, West Texas Written
 by: Loring Schaible Contact:
 [dpschai@sandia.gov](mailto:dpschai@sandia.gov) Last updated: Sept. 23,
 2024 The file describes the Supplemental Data provided for the paper
 'Proximal observations of epicentral infrasound generated by shallow
 low-magnitude earthquakes in the Permian Basin, West Texas' published
 in the BSSA, DOI:10.1785/0120240033. The DOI of the data described here
 is: 10.5061/dryad.g1jwstr03. This folder contains the infrasound data
 recorded on Hyperion microbarometers on April 1, 2023 by instruments:
 BEZO.6 SHED.1,2,3,5 WIND.1,3 * As noted in the paper, these were the only
 instruments that were working properly during earthquakes TX2023GJPM and
 GJYC. * Instruments SHED.1,2,3 and WIND.1 were analog with data recorded
 on RefTek 130S digitizers. Instruments BEZO.6, SHED.5, and WIND.3 were
 digital with a built-in digitizer. The units of the .SAC files is Pascals.
 All processing was done using Obspy. The Obspy commands used are shown
 below in quotations. Each file is a day-long .SAC file from
 2023-04-01T00:00:00.00 to 2023-04-01T23:59:59.99 UTC0. Raw data were
 rewritten from their native formats to .SAC files. In this process, raw
 counts were converted to Pascals by multiplying the recorded number of
 counts by the RefTek/Hyperion nominal calibration value of 2.34e-5 Pascals
 per counts. The individual waveforms were demeaned and linearly detrended.
 "st[0].data=st[0].data*calib"
 "st.detrend(type="demean")"
 "st.detrend(type="linear")" The day-long files were
 created from merging the .SAC files created above . In merging those
 files, gaps were filled with values of 0. The merged waveforms were
 demeaned and linearly detrended. "st.merge(method=0, fill_value=0,
 interpolation_samples=0)"
 "st.detrend(type="demean")"
 "st.detrend(type="linear")" In our paper, the only
 subsequent processing of these files was to resample all waveforms to 100
 Hz sampling rate, bandpass filter all waveforms to a common band of 5-50
 Hz, and trim the waveforms to the duration of interest.
 "st.resample(100.0)" "st.filter("bandpass",
 freqmin=5, freqmax=50)" "st.trim(starttime=tb, endtime=te)"
 Each waveform has latitude and longitude information embedded in the
 attributes. "trace.stats.sac"