The Pacific OBS Research into Convecting Asthenosphere (ORCA) Experiment

The Pacific ocean‐bottom seismometer (OBS) Research into Convecting Asthenosphere (ORCA) experiment deployed two 30‐station seismic arrays between 2018 and 2020—a US contribution to the international PacificArray project. The “Young ORCA” array deployed on ∼40 Ma central Pacific seafloor had a ∼68% data recovery rate, whereas the “Old ORCA” array deployed on ∼120 Ma southwest Pacific seafloor had a ∼80% recovery rate. We detail here the seismic data quality, spectral characteristics, and engineering challenges of this experiment. We provide information to assist users of this dataset, including OBS orientations and tables of daily data quality for all channels. Preliminary analysis illustrates the utility of these data for surface‐ and body‐wave seismic imaging.