Low electrical resistivity associated with plunging of the Nazca flat - slab beneath Argentina ( supplementary note on data analysis )

The crust and uppermost mantle structure of Southern Peru from ambient noise and earthquake surface wave analysis

a r t i c l e i n f o a b s t r a c t Southern Peru is located in the northern Central Andes, which is the highest plateau along an active subduction zone. In this region, the Nazca slab changes from normal to flat subduction, with the associated Holocene volcanism ceasing above the flat subduction regime. We use 6 s to 67 s period surface wave signals from ambient noise cross-correlations and ...

Effects of change in slab geometry on the mantle flow and slab fabric in Southern Peru

The effects of complex slab geometries on the surrounding mantle flow field are still poorly understood. Here we combine shear wave velocity structure with Rayleigh wave phase anisotropy to examine these effects in southern Peru, where the slab changes its geometry from steep to flat. To the south, where the slab subducts steeply, we find trench-parallel anisotropy beneath the active volcanic a...

Upper mantle anisotropy beneath Peru from SKS splitting: Constraints on flat slab dynamics and interaction with the Nazca Ridge

Internal deformation of the subducted Nazca slab inferred from seismic anisotropy

Withinoceanic lithospherea fossilized fabric is oftenpreserved originating from the time of plate formation. Such fabric is thought to form at the mid-ocean ridge when olivine crystals align with the direction of plate spreading1,2. It is unclear, however, whether this fossil fabric is preserved within slabs during subduction or overprinted by subduction-induced deformation. The alignment of ol...

Structure of the subduction transition region from seismic array data in southern Peru

S U M M A R Y Data from three seismic arrays installed in southern Peruwere analysed using receiver functions from P, PP and PKP wave phases, in order to image the subducted Nazca slab. The arrays cover the transition region from flat slab subduction in central Peru to normal subduction with an angle of about 30◦ further south. A previous study used data from the first array in the normal subdu...