Along-Strike Forearc and Subducted Upper Slab Structure beneath North Chile and their Implications towards occurrence of Slow Slip

We estimated the lithospheric structure beneath the forearc of North Chile subduction zone, extending from Iquique to Valparaiso, with overlapping slow slip areas. Thickness and velocity of subducted oceanic crust, slab top, subducted oceanic Moho, continental Moho, and wedge mantle velocity were computed. We investigated relative differences of seismic velocities around plate interface, especially from lower wedge mantle bottom, upper subducted oceanic crust and oceanic mantle, near and away from the slow slip areas. Here we show that the disparities were more pronounced near south of Iquique szone (19oS-25oS). Near Valparaiso, the velocities of upper oceanic mantle differ. These discrepancies in velocities are regarded as presence of fluids from subducted ridges and seamounts, which might alter seismicity in the area. We hypothesize that seismological structure could potentially regulate slow slip in Iquique, as a combined effect from lower wedge mantle, oceanic crust, and subducting mantle.