Applications of teleseismic P phases to structure of the crust and upper mantle in Eastern Queensland, Australia

Hearn, S. J. (1982). Applications of teleseismic P phases to structure of the crust and upper mantle in Eastern Queensland, Australia PhD Thesis, School of Physical Sciences, The University of Queensland. doi:10.14264/uql.2014.577

       
Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
THE2587.pdf Thesis full text application/pdf 3.71MB 2

Author Hearn, S. J.
Thesis Title Applications of teleseismic P phases to structure of the crust and upper mantle in Eastern Queensland, Australia
School, Centre or Institute School of Physical Sciences
Institution The University of Queensland
DOI 10.14264/uql.2014.577
Publication date 1982
Thesis type PhD Thesis
Supervisor J. P. Webb
Total pages 213
Language eng
Subjects 040407 Seismology and Seismic Exploration
Formatted abstract
Short-period recordings of P phases from deep teleseismic earthquakes have been applied to the determination of crust and upper-mantle structure.

At stations in eastern Queensland, P residuals from deep earthquakes in the Fiji region depend systematically on the geographical location of events. The preferred explanation is in terms of lateral variation in velocity structure beneath the Fiji-Tonga seismic zone.

The spatial variation of P residuals in eastern Queensland has been examined using the relative-residual approach. A composite delay pattern has been obtained for Fijian earthquakes by integrating observations made during a number of short-term surveys. Consistent relative delays in excess of one second are observed. Observations from selected teleseisms in other source regions indicate significant azimuthal variations in delay patterns at some stations. The main features of the observed residual field are consistent with laterally varying velocities beneath the receiving region, occurring in the depth range 100 - 300 km.

A means of obtaining information of relevance to near-station structure, from within the recorded P coda of deep teleseismic earthquakes, has been assessed. The phenomenon of spectral ratio periodicity has been examined, and the optimum strategy for practical application of the concept considered. Evaluation of the periodicity technique using recordings of deep teleseisms at stations in Queensland suggests that much of the energy within the P coda of such events is apparently incoherent from event to event. Nevertheless, the technique may be of use in providing constraints for models of crustal structure in the receiving region.
Keyword Seismology -- Queensland
Earth (Planet) -- Crust
Earth (Planet) -- Mantle

Document type: Thesis
Collection: UQ Theses (RHD) - UQ staff and students only
 
Citation counts: Google Scholar Search Google Scholar
Created: Fri, 12 Dec 2014, 09:09:00 EST by Mary-Anne Marrington on behalf of Scholarly Communication and Digitisation Service