Depths of mantle discontinuities beneath Peru using receiver function analysis : Seismology Course

We analyzed 182 broadband waveforms recorded by the Nana station, (NNA), which belongs to the Incorporated Research Institutions for Seismology (IRIS) to determine the depths of the 410 km and 660 km discontinuities and thickness of the mantle transition zone beneath central Peru by the receiver function method. The transition zone is estimated to be thicker than a global average beneath the NNA station where previous seismic tomography shows slower P-velocities than a global average, which cannot be explained by temperature anomalies. A small amount of water associated with the subduction of the Nazca plate may explain the present result as well as the tomographic result, since the experimental studies indicate that water should thicken the transition zone and reduce seismic velocities.