Title: Data: Ocean-bottom P and S arrival waveform dataset from the Alaska Amphibious Community Seismic Experiment, 2019 Author: Grace Barcheck Cornell University grace.barcheck@cornell.edu https://orcid.org/0000-0002-1773-1577 Description: This archive contains an earthquake waveform dataset and corresponding metadata generated from offshore ocean-bottom seismic data collected in 2019 as part of the Alaska Amphibious Community Seismic Experiment (AACSE) (Ruppert et al., 2022, SRL; Barcheck et al., 2020, SRL; Abers et al., 2019, EOS). AACSE was deployed May 2018 through August 2019, and the experiment collected seismic data both on- and off-shore along a stretch of the Alaska-Aleutian subduction zone near the Alaska Peninsula. The Alaska Earthquake Center created the authoritative, analyst-checked earthquake catalog for the experiment (Ruppert et al., 2022), and the catalog contains a list of earthquake origin times and locations during AACSE as well as arrival times of P and S waves at many seismometers for each earthquake. The P and S arrival times from Ruppert et al. (2022) were used to create this dataset. Each waveform corresponds to one earthquake recorded at one ocean-bottom seismic station. Waveforms are 150 seconds long and have been cut out starting 45 seconds before the first station arrival time for that event (P or S) in the analyst-checked Ruppert et al. (2022) earthquake catalog. Each waveform contains 4 channels of information (4 “components” in seismology jargon): The Z channel contains vertical ground velocity recorded by the seismometer; channels 1 & 2 contain two perpendicular components of ground velocity recorded by the seismometer (orientation unknown); the H channel contains hydrophone (acoustic) data from the water column. Many stations did not record hydrophone data, and the H component is empty. No instrument correction has been applied to any of these data, so all components are in units of counts. Sampling rate is nominally 100 samples per second, though exact sample rate varies instrument-to-instrument for ocean bottom seismic data because of clock drift at the bottom of the ocean. Clock drift is assumed linear at a station and was modeled and removed prior to data download for all ocean-bottom seismometers that were still running and able to get a clock lock upon recovery (documented here: http://ds.iris.edu/data/reports/XO_2018_2019/). Stations without known clock drifts are also included in this dataset, as relative timing error from very small sample rate errors are expected to be small over 150 seconds. Stations with problematic timing are documented in the supplement of Barcheck et al. (2020). The structure of the data for each waveform is nominally a 4 row x 15000 column array, with each row being one of the 4 components. Number of columns varies slightly, because of sample rate variability from clock drift and the 150 second duration. For each waveform, all 4 channels are sampled at identical timestamps, which can be reconstructed from the metadata. All data is from ocean-bottom instruments (no data recorded on land). A separate file contains comparable data from 2018. Data collection dates: Continuous waveform data used to construct this dataset were collected as part of AACSE between January 1, 2019 and August 24, 2019, and archived at iris.edu. Details are in Barcheck et al., 2020, SRL. Data retrieval and file creation date: Waveform data were downloaded from iris.edu and the dataset was created in May, 2022. Funding: Dataset creation was funded by the U.S. Geological Survey under Grant No. G22AP00040. The Alaska Amphibious Community Seismic Experiment was funded by NSF Award #1654568. Archive contents: Waveform data: - The file "archive_waveforms2019.tar.gz" contains eight (8) HDF5-formatted files containing the waveform data, one file for each month (Jan-Aug) of the experiment in 2019. Data are stored in nominally 4x15000 element arrays, representing seismometer velocity counts recorded at 15000 discrete points in time over 1.5 minutes on 4 channels: vertical (Z), horizontal 1 of unknown orientation (1), horizontal 2 of unknown orientation but perpendicular to 1 (2), and hydrophone (H). As described above, array lengths vary slightly because of ocean-bottom clock drift and resulting slight inter-station variations in sample rate. - Each monthly waveform filename is formatted "waveformsYYYYMM.hdf5", where YYYY and MM are the year and month, respectively, of the data contained in the file. Metadata: - The file "archive_metadata2019.tar.gz" contains corresponding metadata for each month of waveform data in .csv formatted files. - Each monthly metadata filename is formatted "metadataYYYYMM.hdf5", where YYYY and MM are the year and month, respectively, of the metadata contained in the file. Data format: - HDF5 internal file format and csv headers match the format used in SeisBench (Woollam et al., 2022, SRL). Further description of file format and header names can be found in Woollam et al., 2022, SRL. Dataset notes: Additional data from 2018 is contained in a separate archive. Waveform dataset component order is labeled internally to HDF5 files as ZNEH, but is in fact Z12H, with 1 and 2 being horizontal components of unknown orientation, and H being a hydrophone component, where available. Citation: Barcheck, Grace (2023) Dataset: Ocean-bottom P and S arrival waveform dataset from the Alaska Amphibious Community Seismic Experiment, 2018-19. [dataset] Cornell University Library eCommons Repository. https://doi.org/10.7298/01da-ka24 References: The earthquake catalog comes from Ruppert et al., 2022, SRL (https://doi.org/10.1785/0220220226) More information about the experiment can be found in Barcheck et al., 2020, SRL (https://doi.org/10.1785/0220200189); Abers et al., 2019, EOS (https://doi.org/10.1029/2019EO117621) More information about Seisbench can be found in Woollam et al., 2022, SRL (https://doi.org/10.1785/0220210324); Munchmeyer et al., 2022, JGR Solid Earth (https://doi.org/10.1029/2021JB023499) Date archived: November 2023 License: This dataset is licensed under Creative Commons License: Attribution 4.0 International (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/legalcode).