Near-vertical-incidence seismic reflection imaging of the Australian continental Moho: Effect of acquisition and processing  

Authors / CoAuthors

Jones, L.E.A.

Abstract

For the last 50 years, Geoscience Australia and its predecessors have been collecting onshore near-vertical-incidence deep seismic reflection data, first as low fold explosive data and more recently as high fold vibroseis data. These data have been used in conjunction with other seismic data sets by various research groups to construct depth to Moho models. The Moho has been interpreted either as a strong reflector per se, or as the bottom of a reflective band in the lower crust. However the amplitude standout of the Moho can be very much dependent on the fold of the data and applied processing sequence. Some low fold explosive data was re-processed by Geoscience Australia to enhance the Moho for comparison with recent vibroseis data, in the Mt Isa province in Queensland, and in the Southern Delamerian and Lachlan Fold Belts in Victoria. Marked improvement was achieved by time-variant band-limited noise suppression of reverberations, as well as by coherency weighted common mid point stacking. Post stack migration can also improve the clarity of the Moho, provided there is enough continuity of the data to avoid migration 'smiles'. An important consideration was amplitude scaling, with a time variant automatic gain control (AGC) employed before stack, and a weighted AGC applied after stack, in order to preserve seismic character. These results demonstrate that processing and acquisition issues need to be understood in order to assess the reflective character of the Moho and indeed to interpret its location.

Product Type

nonGeographicDataset

eCat Id

71479

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Keywords

• External Publication

( Theme )

• seismic reflection

( Theme )

• seismic sections

( Theme )

• seismology

• AU

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_Internal

Publication Date

2011-01-01T00:00:00

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Australian Government Security ClassificationSystem    

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Creative Commons Attribution 4.0 International Licence    

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geoscientificInformation

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[-40.0, -10.0, 113.0, 156.0]

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