3-D tomographic P- and S-wave seismic velocity models of the Galápagos Plume (MarineIGUANA, IGUANA)

This data set consists of 3-D tomographic models of the P- and S-wave seismic velocity structure of the mantle beneath the Galápagos Archipelago, Galápagos Platform, and surrounding oceanic region. The models were derived from teleseismic earthquake arrivals recorded on ocean-bottom seismometers and onshore seismic stations as part of the MarineIGUANA and IGUANA seismic experiments. The model and results are described in Hufstetler et al. (2026). The MarineIGUANA experiment included 49 broadband ocean-bottom seismometers deployed from April 2023 to June 2024, together with 6 land stations, including the permanent PAYG station and 5 stations on Isabela operated by the Instituto Geofísico, Escuela Politécnica Nacional. These stations covered an approximately 650 km by 900 km region spanning the Galápagos Archipelago, the Galápagos Platform, and the nearby spreading center. The data set also includes arrivals from the earlier IGUANA land array, which consisted of 10 island stations deployed from September 1999 to March 2003, including PAYG. Teleseismic arrivals were measured for earthquakes with magnitudes Mw ≥ 5.5 and epicentral distances of 33°-145°. Phase picks include P and Pdiff for compressional waves and S, SKS, Sdiff, and sS for shear waves. For the MarineIGUANA deployment, 3,897 P-wave arrivals from 88 events and 1,294 S-wave arrivals from 33 events remained after cross correlation, with mean measurement uncertainties of 0.083 s for P waves and 0.32 s for S waves. From the earlier IGUANA land deployment, 806 P-wave arrivals from 107 events and 655 S-wave arrivals from 78 events are included, with mean measurement uncertainties of 0.075 s and 0.23 s for P- and S-waves, respectively. In total, the final data set consists of 4,703 P-wave delay times and 1,949 S-wave delay times. Waveforms were processed by removing instrument responses, filtering with a zero-phase third-order Butterworth bandpass filter from 0.02–0.1 Hz, and measuring relative delay times using multi-channel and single-channel cross-correlation approaches. P-wave arrivals were measured on the vertical component, while S-wave arrivals were measured on the transverse component after rotation. The velocity models were produced using a finite-frequency teleseismic body-wave tomography approach that inverts relative travel-time residuals for isotropic slowness perturbations. The final preferred models extend to 700 km depth; deeper model-extent tests indicated that structure below this depth is less well constrained by the array aperture. The NetCDF files provided here have been masked by ray coverage, so velocity perturbation values are included only where sufficient ray coverage exists. There are 2 NetCDF model files: one P-wave velocity perturbation model and one S-wave velocity perturbation model. Each file is formatted with UTM coordinates (UTM zone 35N) and with perturbations on a grid that is spaced 10 km horizontally and vertically. The files contain longitude, latitude, depth (km), UTM easting (m), UTM northing (m) and either P- or S-wave perturbation (%). Velocity perturbations are reported as percent change from the AK135 reference model. The model grid spans longitudes −98.94° to −85.058°E, latitudes −4.946° to 4.946°N, and depths from 0 to 700 km, with positive depth downward. The horizontal grid spacing is 0.09° in both longitude and latitude, and the model values are provided using a vertex-based data layout. The models are stored in NetCDF4 format and were converted to NetCDF using CRESCENT data tools on 2026-04-23. This data set was generated as part of the MarineIGUANA project, which investigated mantle plume structure, plume–lithosphere interaction, and mantle transport pathways beneath the Galápagos hotspot and nearby spreading center. Funding was provided by NSF grant OCE-1928197.