Probabilistic earthquake risk maps of southwest Western Australia

New earthquake risk maps of southwest Western Australia including continental margins have been prepared. The risk is depicted as contours of peak ground velocity, acceleration, and ground intensity with a 10 per cent probability of being exceeded in 50 years. The maps are based on the Cornell-McGuire methodology. Ten earthquake source zones have been thus defined and corresponding recurrence relations derived. The relation obtained, using a maximum-likelihood fit, for the primary zone to the east of Perth, is log N = 3.66-0.90 ML, where N is the number of events greater than or equal to the Richter magnitude, ML. Local intensity attenuation constants, a, b, and c, are derived for the expression I = aebMLR-c, where I is the estimated Modified Mercalli intensity at a hypocentral distance R km from an earthquake of magnitude ML. Using the relation log A= I/3.1-2.3 to convert the intensity to peak ground acceleration, A in m.s-2, the adopted constants were 0.025, 1.10 and 1.03 respectively. Similarly, using the empirical formula 21 = 7v/5 to convert intensity to peak ground velocity, v in mm.s-1, the corresponding values were 3.30, 1.04 and 0.96, respectively. The contour expressing the greatest risk in the area of interest is that of a peak ground velocity of 160 mm.s-1, and it encloses an area of about 2000 km2 centred on the most active source zone east of Perth. The value for Perth city is 48 mm.s-1. Increasing (i) the maximum magnitude from ML 7.5 to ML 8.5; (ii) the depth of earthquake foci from 5 km to 15 km; (iii) the b value from 0.90 to 0.94; and (iv) the attenuation constants to their estimated maximum value, in the primary source zone, changes the Perth velocity contour from 48 mm.s-1 to 56 mm.s-1 , 48 mm.s-1 , 42 mm.s-1 , and 58 mm.s-1, respectively. The omission of a suspected seismic gap 100 km east of Perth from the primary source zone changes the velocity contour from 48 mm.s-1 to 46 mm.s-1. Sensitivity to adopting another empirical relation between peak ground acceleration and intensity has been examined. This increases the risk at Perth from 0.44 m.s-2 to 0.65 m.s-2. We recommend a microzonation study of Perth and installation of more strong-motion instruments to improve our risk estimates, which should be updated in 5-10 years.

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Date (Publication)
1987-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/81214

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Bureau of Mineral Resources, Geology and Geophysics

 Canberra
Author

Gaull, B.A.

 1
Author

Michael-Leiba, M.O.

 2
Name

BMR Journal of Australian Geology and Geophysics

Issue identification

10:2:145-151

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Role Organisation / Individual Name Details
Custodian

Corp
Owner

Commonwealth of Australia (Geoscience Australia)
Custodian

Commonwealth of Australia (Geoscience Australia)

 Voice
Topic category
  • Geoscientific information

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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

Keywords

  • WA

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

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http://creativecommons.org/licenses/

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License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
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https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Language
English
Character encoding
UTF8

Distribution Information

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Distributor

Commonwealth of Australia (Geoscience Australia)

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OnLine resource

Journal article (pdf)

Journal article (pdf)

Distribution format

  • pdf

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Unknown

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Non geographic dataset
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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-709b-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/81214

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/fae9173a-709b-71e4-e044-00144fdd4fa6

Date info (Revision)
2018-04-20T06:09:57
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

 
 

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