At active continental margins, the subduction of lithospherical plates often leads to trench building; such is the case where the oceanic Nazca Plate meets the continental South American Plate. As part of the Subduction Processes Off Chile (SPOC) project, 2D reflection seismic data were acquired by the German Bundesanstalt f¿r Geowissenschaften und Rohstoffe covering the Peru-Chile trench between 28¿S and 44¿S. To the south of 31¿S, the trench is filled with terrigenous sediments. The images of the subsurface along some lines are characterized by a depth-dependent quasi-periodic variation of the reflections. This variation was investigated using a cross-correlation technique.The maxima of the seismic cross-correlation function were compared to those of the temperature curve over the past 420 kyr. We hypothesize that the variation of the climate over this period is mirrored in the seismic reflection coefficient series of the sediments. As this effect is not seen equally well on all lines, it seems that this is a function of the profile location relative to the sediment sources, i.e. submarine canyons.