PRISM3D: a 3-D reference seismic model for Iberia and adjacent areas

SUMMARY We present PRISM3D, a 3-D reference seismic model of P- and S-wave velocities for Iberia adjacent areas. PRISM3D results from the combination most up-to-date earth models available region. It extends horizontally 15°W to 5°E in longitude, 34°N 46°N latitude vertically 3.5 km above 200 below sea level, is modelled on regular grid with 10 0.5 node spacing horizontal vertical directions, respectively. was designed using inferred local teleseismic body-wave tomography, earthquake ambient noise surface wave receiver function analysis active source experiments. includes two interfaces, namely topography/bathymetry Mohorovičić (Moho) discontinuity. The Moho previously published deep sounding results. To that end we used probabilistic reconstruction algorithm allowed extract mean depth along its associated standard deviation, which provides uncertainty estimate. good agreement models, although it presents slightly sharper gardients orogenic areas such as Pyrenees or Betic-Rif system. Crustal mantle speed grids were built separately each side by weighted average existing thus allowing realistically render gradients across interface. deviation also calculated, an estimation values at any point grid. At shallow depths (<10 km), low P S speeds high VP/VS are observed offshore basins, while Iberian Massif, covers large part western Iberia, appears characterized rather flat Moho, higher than VP VS VP/VS. Conversely, system seems be VS, combined comparison rest study area. prominent feature well known anomaly related Alboran slab imaged various tomography studies. consistency previous work verified comparing recent studies, shows general agreement.The impact new illustrated through simple synthetic experiment, lateral variations can produce traveltime differences ranging –1.5 1.5 s waves –2.5 2.5 regional distances. Such far larger phase picking uncertainties would likely affect hypocentral parameter estimations. basis studies including Earth structure investigations geodynamic modelling surroundings.