Abstract
The seismic oceanic Pn phase is characterized by low spatial attenuation, a high-frequency wavetrain of extremely long duration and an onset velocity near 8.0 km s−1. In an effort to explain these properties, models have been proposed for the mode of propagation of this phase which include energy entrapment within a low-velocity channel1,2, propagation within an extremely low-attenuation lithosphere waveguide3,4 and forward-scattering from local heterogeneity within the oceanic crust5,6. Through synthetic seismogram modelling, we have generated realistic oceanic Pn phases for an oceanic lithosph¨re model that did not contain any of these intrinsic properties. The synthetic Pn phase can be explained rather simply as a set of refractions from the lower lithosphre with subsequent reverberations within the oceanic water column and sediment layer. Many of the spectral properties associated with layer reverberation observed in the synthetic Pn phase are revealed in data collected in the south-west Pacific. Complicated oceanic lithosphere models are not required to explain the gross characteristics of Pn propagation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
