3DSlabs – a global tomography-based upper mantle slab geometry model

Subducting slabs play a fundamental role in controlling mantle circulation, plate motions, and surface tectonics. Global slab geometry models such as Slab2 provide an essential community reference by integrating seismicity to describe the geometry of subduction zones worldwide. In many regions, however, slabs are inferred to extend beyond the depth range of seismicity, motivating the incorporation of complementary constraints from seismic tomography.

Here we introduce 3DSlabs, a new global three-dimensional upper mantle slab geometry model constructed from seismic tomography. Following the workflow of Wu et al. (2016), fast tomographic velocity anomalies are interpreted and mapped into continuous three-dimensional slab surfaces using GOCAD. Unlike automated iso-surfacing, this approach allows complex variations in slab dip and curvature to be represented with high fidelity. Furthermore, by mapping seismic velocity directly onto the slab surfaces, 3DSlabs facilitates the identification and tracking of subducted buoyancy anomalies, such as aseismic ridges, plateaus, and hotspot tracks.

To maximize utility for the community, 3DSlabs is integrated with the Geodynamic World Builder (GWB), ensuring direct compatibility with geodynamic codes such as ASPECT. The resulting high-fidelity model is well suited for instantaneous mantle flow modeling and investigations of slab–mantle interaction. The inferred subducted features mapped onto these surfaces further provide new opportunities to investigate how along-slab heterogeneities influence subduction dynamics.