Seismotectonic implications of the South Chile ridge subduction beneath the Patagonian Andes

The South Chile ridge (SCR) intersects the Patagonian trench around 46°09′S, forming triple junction among Antarctic, Nazca, and America plates. Subduction of SCR since ~18 Ma produced opening a slab window beneath Patagonia noticeable magmatic gap in cordillera, profuse volcanism topographic uplift retroarc. To study seismicity distribution present-day stress resulting from this particular framework, we analyse databases seismic events earthquake focal mechanisms. Our finds that clusters intraplate crustal are disrupted by ~450–470 km above window. Calculated tensors depict strike-slip tectonic regime north junction, ~W-E compression to south gap. We propose seismotectonic behaviour upper plate is disturbed at first order trench-ridge intersection, leading heterogeneous field.