Heterogeneous seismic anisotropy beneath Madeira and Canary archipelagos revealed by local and teleseismic shear wave splitting

SUMMARY Mid-plate upward mantle flow is a key component of global convection, but its patterns are poorly constrained. Seismic anisotropy the most direct way to infer as well melt distribution, yet convection associated with plume-like upwelling understudied due limited seismic data coverage. Here, we investigate beneath Madeira and Canary hotspots using dense set shear wave splitting observations combining teleseismic local events recorded by three-component broad-band short-period stations. Using total 26 stations in archipelago 43 around Islands, obtain 655 high-quality measurements that reveal heterogeneous patterns. Although event results sparse islands, can observe small average S-wave times 0.16 ± 0.01 s, which significantly increase source depth El Hierro (>20 km) Tenerife (>38 up 0.58 0.47 0.05 s. This suggests an influence pocket orientation magma reservoirs developed at uppermost-mantle depths. Likewise, increases islands shield stage volcanism (up 9.81 1.78 per cent Hierro, western Canaries, against values 1.76 0.73 Lanzarote, eastern Canaries). On average, SKS-wave delay large (2.19 s), indicating sublithospheric primary for region. In show smaller SKS (1.93 0.07 s) than ones (2.25 0.11 could be explained destructive interference above upwelling. Despite complex fast polarization directions throughout both regions, some azimuthal pattern across close observed related present-day frozen lithosphere since before 60 Ma. Additionally, current presence plume archipelagos leads complex, small-scale observations.