Stresses in the Australian crust: evidence from earthquakes and in-situ stress measurements

Evidence from earthquake focal mechanisms, in situ stress measurements, and surface deformations indicate that the Australian continent is in a state of substantial horizontal compression. Reliable focal mechanism determinations are now available from eight earthquakes that have occurred in several parts of the continent since 1967. Each of these mechanisms indicates that the faulting associated with the earthquakes was caused by compressive stress acting close to horizontal. In situ measurements made in mines and tunnels, and close to the surface in quarry floors or on rock outcrops, also indicate horizontal compressive stress in all areas. Near the epicentres of the 1968 Meckering and 1970 Calingiri earthquakes, shallow over-coring measurements (<10 m) were carried out to compare the in situ observations with the earthquake focal mechanisms and surface faulting. The measurements were made in competent granite at seven locations along a 200 km north-south traverse. The results indicate a high regional compressive stress acting about 77°E of N. This agrees well with the 91° and 102°E of N directions for the pressure axes obtained respectively from the earthquake focal mechanisms. The highest stress (23 MPa) was measured at the site farthest north from the Meckering epicentre, and the lowest stress was close to that epicentre where the maximum principal stress was about 4 MPa. During 1978 and 1979 several sites in NSW were tested at depths ranging from 3 to 9 m. At each site the stress measured was compressive. In the eastern part of the State at Buckleys Lake, Jindabyne, Milton, and Moruya the axes of maximum compression were north-south, but in the west at Ardlethan, Mirrool, Berrigan, and Tocumwal the stresses are close to east-west, agreeing with the earlier results at Broken Hill and Cobar. The highest values of about 20 MPa were obtained in Silurian granite at Tocumwal. The results give principal stress orientation in different directions for different regions of the continent; it is therefore clear that simple models derived from plate tectonic concepts cannot be applied directly to explain the high observed stresses or their directions.

Simple

Identification info

Date (Publication)
1979-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/81007

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Bureau of Mineral Resources, Geology and Geophysics

 Canberra
Author

Denham, D.

 1
Author

Alexander, L.G.

 2
Author

Worontnicki, G.

 3
Name

BMR Journal of Australian Geology and Geophysics

Issue identification

4:3:289-295

Point of contact
Role Organisation / Individual Name Details
Custodian

Corp
Owner

Commonwealth of Australia (Geoscience Australia)
Custodian

Commonwealth of Australia (Geoscience Australia)

 Voice
Topic category
  • Geoscientific information

Extent

N
S
E
W


Maintenance and update frequency
Unknown

Resource format

Title

Product data repository: Various Formats

Website

Data Store directory containing the digital product files

Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes

Keywords

  • GA Publication

  • Journal

Theme

  • marine

Keywords

  • AUS

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Earth Sciences

Keywords

  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

http://creativecommons.org/licenses/

Access constraints
License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Language
English
Character encoding
UTF8

Distribution Information

Distributor contact
Role Organisation / Individual Name Details
Distributor

Commonwealth of Australia (Geoscience Australia)

 Voice
OnLine resource

Journal article (pdf)

Journal article (pdf)

Distribution format

  • pdf

Resource lineage

Statement

Unknown

Hierarchy level
Non geographic dataset
Other

GA Publication

Description

Source data not available.

Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/fae9173a-6fcc-71e4-e044-00144fdd4fa6

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice

Type of resource

Resource scope
Document
Name

AGSO BMR Journal

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/81007

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/fae9173a-6fcc-71e4-e044-00144fdd4fa6

Date info (Revision)
2018-04-20T06:10:14
Date info (Creation)
2014-06-03T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Spatial extent

N
S
E
W


Keywords

marine

Provided by

Access to the portal

Associated resources

Not available