Data Sheet 1_LitModDyn: quantifying dynamic topography induced by slab–mantle interaction beneath the Adria microplate.docx

We apply this approach to two published transects across the Adria microplate, where slab rollback and slab detachment/breakoff provide a natural laboratory for investigating the surface response to mantle processes. Our results show that the resulting dynamic topography along both transects is modest in amplitude, generally remaining below 400 m. Beneath the northern Apennines, a west-dipping attached slab extending below 400 km produces the largest dynamic subsidence, reaching up to ∼400 m.

In contrast, slab detachment beneath the southern Apennines leads to reduced stress transmission to the surface, resulting in a weaker negative dynamic topography of only ∼120 m despite enhanced mantle flow. Along the eastern margin of Adria, the dynamic contribution increases southward, reaching ∼150 m beneath the southern Dinarides, while remaining negligible beneath the northern Dinarides, consistent with variations in slab geometry.

Comparison with residual topography indicates that mantle-driven dynamics account for a substantial fraction of the residual elevation in the northern Apennines, whereas lithospheric heterogeneities largely control residual topography beneath the southern Adriatic domain and the Dinarides. These results indicate that slab geometry exerts a primary control on lithosphere–mantle coupling. Attached, high-density slabs enhance mantle flow, promote focused downwelling and adjacent upwelling, and amplify dynamic topography.

In contrast, slab detachment accelerates mantle flow, but the resulting decoupling from the overlying lithosphere reduces stress transfer and weakens the surface dynamic response.</p>