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.

中文翻译：

---

胡安费尔南德斯海脊对全波形反演推断的潘潘平俯冲的影响

一个新的中安第斯山脉中南部地壳和上地幔地震模型是从全波形反演中推导出来的，覆盖了 Pampean 平坦俯冲和相邻的 Payenia 陡峭俯冲段。集中的地壳低速异常表明沿着火山弧在 Payenia 段发生部分熔体，而覆盖 Pampean 段广泛区域的较弱的低速异常被解释为残余部分熔体。从沿胡安费尔南德斯山脊的内陆投影的平板中的间隙推断出平坦的纳斯卡平板的变薄和撕裂。平板下方地幔中的高速异常被解释为遗迹纳斯卡板块片段，这表明在压平过程中胡安费尔南德斯海脊的浮力引发了较早的板块断裂。在佩尼亚，