# Ground-motion records and site information for Puerto Rico and the U.S. Virgin Islands, 2006-2024 Recommended citation for this data release: Aagaard, B. T., Stephenson, W. J., Ahdi, S. K., and Herrick J. A. (2025). Ground-motion records and site information for Puerto Rico and the U.S. Virgin Islands, 2006-2024. Center for Engineering Strong Motion Data (CESMD), doi: 10.5066/P14E4GXW. ## Files The `time_series` folder contains the gmprocess workspace Adaptable Seismic Data Format (ASDF) files with the raw and processed time series and ground-motion metrics. The `mixed_effects` folder contains the results of the linear mixed effects analysis. `PRVI_SARotD50.csv` Comma-separated-value file of ground-motion records with median peak horizontal ground velocity, peak horizontal ground acceleration, and horizontal acceleration response spectra (5% damped) at 21 periods (0.01-10 s). The median peak horizontal value, also called RotD50, is the median value across all horizontal orientations. `PRVI_SARotD50_selected.csv` Same as `PRVI_SARotD50.csv` but with a subset of records meeting the record selection criteria, including a minimum of three records per earthquake and three records per station. For active crustal earthquakes, the maximum rupture distance is 300 km. For subduction interface and intraslab earthquakes, the minimum earthquake magnitude is 4.5, and the maximum rupture distance is 550 km. `EarthquakesClassification.csv` Comma-separated-value file with earthquake information from the Advanced National Seismic System Comprehensive Catalog (ANSS ComCat; https://doi.org/10.5066/F7MS3QZH). The file also includes classification of the fault type (strike-slip, reverse, and normal) if available and earthquake classification (active crustal, subduction interface, and subduction intraslab). The earthquake classification (https://doi.org/10.5066/P13E7CAY) is based primarily on the distance to the top of the subducting slab as defined by Slab 2.0 (https://doi.org/10.5066/F7PV6JNV). `StationsVs30.csv` Comma-separated-value file with station Vs30 values (time averaged shear wave speed in the top 30 m) compiled from site surveys. The file values for 38 of the 71 stations in our dataset. Values come from three data sources. Odum and others (https://doi.org/10.1785/0120120349) provides values at 6 stations (OdumEtAl2013) from noninvasive, collocated, active-source body-wave (refraction/reflection), active-source surface wave, and passive-source surface-wave refraction microtremor (ReMi) techniques. Claros Gomez (2022) provides values at 19 stations by converting the fundamental frequency in the ambient field horizontal to vertical spectral ratio (HVSR) analysis to Vs30 based on data from Odum and others (https://doi.org/10.1785/0120120349). Claros Gomez uses the equation, Vs30(m/s) = 106.9 f0(Hz) + 29.75, to compute a proxy Vs30 value from fundamental frequency f0 obtained from HVSR analysis. Lindberg and others (https://doi.org/10.5066/P134BAGK) provide values at 13 stations from multichannel analysis of surface waves (MASW). `PRVI_Waveforms.yml` YAML file with FDSN (International Federation of Digital Seismograph Networks) search parameters along with stations and earthquakes excluded from the ground-motion records file. `colocated.yml` YAML gmprocess configuration file with custom settings for handling colocated sensors. `PRSMP.xml` STATIONXML file with instrument response information for stations in the PR seismic network that are managed by the Puerto Rico Strong Motion Program. This information was used instead of the instrument response information available through the EarthScope Consortium web services (https://service.iris.edu), because we found that the instrument response information contained incorrect sensor sensitivities and data logger gains at some stations as described in the next section. ## Instrument response issues We found the instrument response information downloaded between October 2023 and April 2024 from the EarthScope Consortium web services (https://service.iris.edu) for the following stations contained incorrect values for the sensor sensitivity or data logger gain: PR.BY02 PR.CG01 PR.ROPR PR.SNC1 PR.BRR1 PR.GNC1 PR.GYN1 PR.LJS1 PR.SNS1 PR.CBR1 PR.CLB1 PR.CLS1 PR.COM1 PR.CR01 PR.GY01 PR.GYM1 PR.HM01 PR.MNB1 PR.MRC1 PR.NGB1 PR.SNG1 PR.TA02 PR.VQS2 We used the instrument response information in PRSMP.xml for these stations. ## Data processing We processed the raw ground motions using gmprocess (https://doi.org/10.5066/P9ANQXN3, Git hash ab5a8a651f509b52b18d87e69374c45e802fbeae). We customized the handling of colocated sensors to give priority to strong-motion channels using `colocated.yml`. All of the remaining gmprocess settings use the default values. ## File formats ### Columns in `PRVI_SARotD50.csv` and `PRVI_SARotD50_selected.csv` EarthquakeId: Event ID from ANSS ComCat EarthquakeTime: Earthquake origin time (UTC) EarthquakeLatitude: Earthquake latitude (decimal degrees) EarthquakeLongitude: Earthquake longitude (decimal degrees) EarthquakeDepth: Earthquake depth (km) EarthquakeMagnitude: Earthquake magnitude EarthquakeMagnitudeType: Earthquake magnitude type Network: Network code DataProvider: Data source provider StationCode: Station code StationID: Concatenated network, station, and instrument codes StationDescription: Station description StationLatitude: Station latitude (decimal degrees) StationLongitude: Station longitude (decimal degrees) StationElevation: Station elevation (m) SamplingRate: Record sampling rate (Hz) BackAzimuth: Site-to-source azimuth (decimal degrees) EpicentralDistance: Epicentral distance (km) HypocentralDistance: Hypocentral distance (km) SourceFile: Source file RuptureDistance: Closest distance to the rupture plane (km) RuptureDistanceVar: Variance of rupture distance estimate (km^2) JoynerBooreDistance: Joyner-Boore distance (km) JoynerBooreDistanceVar: Variance of Joyner-Boore distance estimate (km^2) GC2_rx: Distance measured perpendicular to the fault strike from the surface projection of the up-dip edge of the fault plane (km) GC2_ry: Distance measured parallel to the fault strike from the midpoint of the surface projection of the fault plane (km) GC2_ry0: Horizontal distance off the end of the rupture measured parallel to strike (km) GC2_U: Strike-normal (U) coordinate, defined by Spudich and Chiou (2015; https://doi.org/10.3133/ofr20151028) (km) GC2_T: Strike-parallel (T) coordinate, defined by Spudich and Chiou (2015; https://doi.org/10.3133/ofr20151028) (km) H1Lowpass: H1 channel lowpass frequency (Hz) H1Highpass: H1 channel highpass frequency (Hz) H2Lowpass: H2 channel lowpass frequency (Hz) H2Highpass: H2 channel highpass frequency (Hz) DURATIONp-q: p-q percent significant duration (s) PGA: Peak ground acceleration (%g) PGV: Peak ground velocity (cm/s) SA(X): Median horizontal spectral acceleration (%g) at X seconds SORTED_DURATION: Sorted significant duration (s) ### Columns in `EarthquakesClassification.csv` EarthquakeId: Event ID from ANSS ComCat Latitude: Earthquake latitude (decimal degrees) Longitude: Earthquake longitude (decimal degrees) DepthKm: Earthquake depth (km) Magnitude: Earthquake magnitude MagnitudeType: Earthquake magnitude type Origin: Earthquake origin time (UTC) FocalMechanism: Earthquake focal mechanism (SS=strike-slip, RS=reverse, NM=normal, ALL=unknown) TectonicRegime-Slab2MaxProb: Tectonic regime using region with maximum probability from STREC (https://www.usgs.gov/index.php/software/seismotectonic-regime-earthquake-calculator-strec) ProbCrustHaynie: Probability that an earthquake is an active crustal earthquake from Haynie (2024; https://doi.org/https://doi.org/10.5066/P13E7CAY). ProbInterfaceHaynie: Probability that an earthquake is a subduction interface earthquake from Haynie (2024). ProbSlabHaynie: Probability that an earthquake is a subduction intraslab earthquake from Haynie (2024). TectonicRegime-Slab2Haynie: Earthquake classification using the algorithm developed by Haynie (2024) for the Puerto Rico seismicity catalog Quality: Quality of earthquake classification from Haynie (2024). Slab2-Region: Slab 2 region TectonicRegime: Earthquake category used in the ground-motion analysis ### Columns in `StationsVs30.csv` NetworkCode: Network code StationCode: Station code Latitude: Station latitude (decimal degrees) Longitude: Station longitude (decimal degrees) Vs30: Vs30 (m/s) from local data sources Vs30_Source: Source for Vs30 value ## References Claros Gomez, D. F., 2022. Ground Motion Prediction Equations for Puerto Rico (Doctor of Philosophy in Civil Engineering). University of Puerto Rico, Mayaguez.