@article {eilon_pacific_2021,
	title = {The Pacific OBS Research into Convecting Asthenosphere (ORCA) Experiment},
	journal = {Seismological Research Letters},
	volume = {93},
	number = {1},
	year = {2021},
	month = {01/2022},
	pages = {477{\textendash}493},
	abstract = {The Pacific ocean-bottom seismometer (OBS) Research into Convecting Asthenosphere (ORCA) experiment deployed two 30-station seismic arrays between 2018 and 2020{\textemdash}a US contribution to the international PacificArray project. The {\textquotedblleft}Young ORCA{\textquotedblright} array deployed on \~{}40~Ma central Pacific seafloor had a \~{}68\% data recovery rate, whereas the {\textquotedblleft}Old ORCA{\textquotedblright} 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.},
	issn = {0895-0695},
	doi = {10.1785/0220210173},
	url = {https://doi.org/10.1785/0220210173},
	author = {Eilon, Zachary C. and Gaherty, James B. and Zhang, Lun and Russell, Joshua and McPeak, Sean and Phillips, Joseph and Forsyth, Donald W. and Ekstr{\"o}m, G{\"o}ran}
}
@article {eddy_age_2019,
	title = {Age dependence and anisotropy of surface-wave phase velocities in the Pacific},
	journal = {Geophysical Journal International},
	volume = {216},
	number = {1},
	year = {2019},
	month = {01/2019},
	pages = {640{\textendash}658},
	abstract = {We present new anisotropic phase-velocity maps of the Pacific basin for Rayleigh and Love waves between 25~and 250~s. The isotropic and anisotropic phase-velocity maps are obtained by inversion of a data set of single-station surface-wave phase-anomaly measurements recorded for paths crossing the Pacific basin. We develop an age-dependent gradient-damping scheme that allows us to reduce the amount of smoothness damping required in the inversion. The observed isotropic phase velocities have a strong age dependence, and our results are consistent with models of half-space cooling: simple phase-velocity models that depend only on seafloor age explain \$40\textbackslashtext{-}97\textbackslashhbox{ per cent}\$ of the data variance for Love waves and \$20\textbackslashtext{-}97\textbackslashhbox{ per cent}\$ for Rayleigh waves. These values represent a large fraction, ranging from 0.55 to 0.99, of the variance reduction of our best-fitting phase-velocity models. We find that 2ζ azimuthal anisotropy is required to fit our Rayleigh wave phase-anomaly data set but that our data do not require Love wave anisotropy. Rayleigh wave anisotropy also exhibits a clear age dependence, with a large decrease in the magnitude of 2ζ azimuthal anisotropy for seafloor older than 70~Ma that cannot be explained simply as a change in anisotropy direction between the lithosphere and asthenosphere. Long-period Rayleigh wave anisotropy directions align well overall with absolute-plate-motion directions, with a median angular misfit of 20{\textdegree} at 125~s. However, we observe large areas within the Pacific basin with a small but consistent offset of 10{\textdegree}{\textendash}20{\textdegree} between the two directions. The disagreement between absolute plate motion and anisotropy for long-period waves suggests the presence of mantle flow beneath the base of the plate in a direction other than absolute plate motion.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggy438},
	url = {https://doi.org/10.1093/gji/ggy438},
	author = {Eddy, Celia L and Ekstr{\"o}m, G{\"o}ran and Nettles, Meredith and Gaherty, James B}
}
