EURUS: a preliminary 3D mantle model of Europe from multifrequency P-wave tomography

Seismic tomography has provided valuable insights into the mantle structure beneath Europe, unveiling key features such as the sources of Cenozoic rifting and volcanism in Central-Western Europe and the dynamics of subduction and slab rollback in the Mediterranean region. However, current tomographic models are constrained by trade-offs: high-resolution models cover limited areas, while broader-scale models lack the detail necessary to resolve finer mantle structures, especially in the lower mantle.

In this study, we introduce EURUS, a preliminary 3D P-wave tomography model of the European mantle, derived using the most extensive dataset of broadband, waveform-based traveltime measurements from 2010 to 2019. This dataset is augmented by analyst-picked travel times from the ISC-EHB catalogue. For our multifrequency tomography, we utilized 6,407,116 cross-correlation measurements in passbands between 30 and 2.7 seconds dominant period.

EURUS achieves high-resolution images (~100 km) of the mantle beneath the Euro-Mediterranean region, extending from the uppermost mantle to depths of approximately 1500 km. While consistent with earlier studies in identifying broad-scale upper-mantle anomalies, EURUS reveals much greater detail and complexity in the transition zone and the uppermost lower mantle, particularly beneath Western Europe and the southern Mediterranean.

In the mid-mantle, a seismically slow structure is observed as a sub-vertical column beneath the European Cenozoic Rift System, intersected by an extensive upper-mantle high-velocity anomaly likely corresponding to the cold Alpine subducted slab. The extension of the South Mediterranean subduction zone is still under investigation. These results highlight the potential of body-wave tomography to enhance our understanding of complex mantle upwelling patterns and slab systems beneath Europe.