Authors / CoAuthors
Goncharov, A.
Abstract
Various aspects of isostasy concept are intimately linked to estimation of the elastic thickness of lithosphere, amplitude of mantle-driven vertical surface motions, basin uplift and subsidence. Common assumptions about isostasy are not always justified by existing data. For example, refraction seismic data provide essential constraints to estimation of isostasy, but are rarely analysed in that respect. Average seismic velocity, which is an integral characteristic of the crust to any given depth, can be calculated from initial refraction velocity models of the crust. Geoscience Australia has 566 full crust models derived from the interpretation of such data in its database as of January 2012. Average velocity through velocity/density regression translates into average density of the crust, and then into crustal column weight to any given depth. If average velocity isolines become horizontal at some depth, this may be an indication of balanced mass distribution (i.e., isostasy) in the crust to that depth. For example, average velocity distribution calculated for a very deep Petrel sedimentary basin on the Australian NW Margin shows no sign of velocity isolines flattening with depth all the way down to at least 15 km below the deepest Moho. Similar estimates for the Mount Isa region lead to opposite conclusions with balancing of average seismic velocities achieved above the Moho. Here, we investigate average seismic velocity distribution for the whole Australian continent and its margins, uncertainties of its translation into estimates of isostasy, and the possible explanations for misbalances in isostatic equilibrium of the Australian crust.
Product Type
nonGeographicDataset
eCat Id
73264
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- External Publication
- ( Theme )
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- crustal structure
- ( Theme )
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- seismic refraction
- ( Theme )
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- seismic velocity
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2012-01-23T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
Lineage
Unknown
Parent Information
Extents
[-75.0, -8.0, 90.0, 170.0]
Reference System
Spatial Resolution
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