Phillips, KristinClayton, Robert W.Davis, PaulTavera, HernandoGuy, RichardSkinner, StevenStubailo, IgorAudin, LaurenceAguilar, Victor2018-07-252018-07-252012-11-28Phillips, K., Clayton, R. W., Davis, P., Tavera, H., Guy, R., Skinner, S., ... Aguilar, V. (2012). Structure of the subduction system in southern Peru from seismic array data.==$Journal of Geophysical Research: Solid Earth, 117$==(B11), B11306. https://doi.org/10.1029/2012JB009540index-oti2018http://hdl.handle.net/20.500.12816/2081The subduction zone in southern Peru is imaged using converted phases from teleseismic P, PP, and PKP waves and P wave tomography using local and teleseismic events with a linear array of 50 broadband seismic stations spanning 300 km from the coast to near Lake Titicaca. The slab dips at 30° and can be observed to a depth of over 200 km. The Moho is seen as a continuous interface along the profile, and the crustal thickness in the back-arc region (the Altiplano) is 75 km thick, which is sufficient to isostatically support the Andes, as evidenced by the gravity. The shallow crust has zones of negative impedance at a depth of 20 km, which is likely the result of volcanism. At the midcrustal level of 40 km, there is a continuous structure with a positive impedance contrast, which we interpret as the western extent of the Brazilian Craton as it underthrusts to the west. Vp/Vs ratios estimated from receiver function stacks show average values for this region with a few areas of elevated Vp/Vs near the volcanic arc and at a few points in the Altiplano. The results support a model of crustal thickening in which the margin crust is underthrust by the Brazilian Shield.application/pdfenginfo:eu-repo/semantics/closedAccessSubductionReceiver functionsLithosphereElastic wavesSeismic stationSeismologyEarth sciencesinfo:eu-repo/semantics/articlehttp://purl.org/pe-repo/ocde/ford#1.05.00http://purl.org/pe-repo/ocde/ford#1.05.04Journal of Geophysical Research: Solid Earthhttps://doi.org/10.1029/2012JB009540