A new seismic model for crust and upper mantle of the south Central Andes is derived from full waveform inversion, covering the Pampean flat subduction and adjacent Payenia steep subduction segments. Focused crustal low‐velocity anomalies indicate partial melts in the Payenia segment along the volcanic arc, whereas weaker low‐velocity anomalies covering a wide zone in the Pampean segment are interpreted as remnant partial melts. Thinning and tearing of the flat Nazca slab is inferred from gaps in the slab along the inland projection of the Juan Fernandez Ridge. A high‐velocity anomaly in the mantle below the flat slab is interpreted as relic Nazca slab segment, which indicates an earlier slab break‐off triggered by the buoyancy of the Juan Fernandez Ridge during the flattening process. In Payenia, large‐scale low‐velocity anomalies atop and below the re‐steepened Nazca slab are associated with the re‐opening of the mantle wedge and sub‐slab asthenospheric flow, respectively.
This code is a python implementation of the p- and s-wave velocity to density conversion approach after Goes et al. (2000). The implementation has been optimised for regular 3D grids using lookup tables instead of Newton iterations.Goes et al. (2000) regard the expansion coefficient as temperature dependent using the relation by Saxena and Shen (1992). In `Conversion.py`, the user can additionally choose between a constant expansion coefficient or a pressure- and temperature dependent coefficient that was derived from Hacker and Abers (2004).For detailed information on the physics behind the approach have a look at the original paper by Goes et al. (2000).
Up-to-date contact information are given on the author's github profile https://github.com/cmeessen.