australia_2012_intro [GEM Hazard Team Wiki]

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====== The 2012 Australia National Seismic Hazard Model ======
The 2012 Australia national seismic hazard model is described in the reports by [[australia_2012_intro#References | Burbidge (2012)]] and  [[australia_2012_intro#References | Leonard et al. (2013)]]. We present here a description of the OpenQuake-engine implementation of the model.

/*=====Basic Datasets=====
==== Earthquake catalogue ====

A composite catalogue is used for this model. The primary data sources are:
  * GG-Cat:  An earthquake catalogue compiled by Gary Gibson from various sources 
  * QUAKES: Geoscience Australia's catalogue of Australian and regional events */

===== The Seismic Source Model =====
The seismic source model consists of three different layers of seismic sources: continental-scale background zones, regional-scale area sources, and small-scale (hot spots) zones describing localized seismic sequences.
Background zones (which contain holes where regional scale sources are defined) are implemented as gridded seismicity models, which are collections of NRML [[https://github.com/gem/oq-nrmllib/blob/master/examples/source_model/point-source.xml|pointSource]] objects. Regional-scale sources and hot-spot zones are instead modeled as NRML [[https://github.com/gem/oq-nrmllib/blob/master/examples/source_model/area-source.xml|areaSource]] objects.\\

The whole source model is divided into the following sub-models:
  * Background and regional cratonic model
  * Background and regional not-cratonic model
  * Hot spots cratonic model
  * Hot spots non-cratonic model
The map below depicts the annual occurrence rate per source (between minimum and maximum magnitudes) for the different source models included in the hazard model. Click the //show map layers// icon to view different source models and base layer maps.

<olmap id="olmap" width="900px" height="600px" lat="-20.0" lon="130.0" zoom="3" statusbar="1" toolbar="1" controls="1" poihoverstyle="0" baselyr="osm" gpxfile="" kmlfile="" geojsonfile="">
</olmap>

<olmap_osmlayer id="olmap" name="Hot spots cratonic - area model" url="http://tilestream.openquake.org/v2/hazard_AUS14-HS_input_cratonic_area/${z}/${x}/${y}.png" visible="true" attribution="Hot spots cratonic model"></olmap_osmlayer>

<olmap_osmlayer id="olmap" name="Hot spots non-cratonic - area model" url="http://tilestream.openquake.org/v2/hazard_AUS14-HS_input_noncratonic_area/${z}/${x}/${y}.png" visible="true" attribution="Australia 2012 Hot Spots Non Cratonic Model"></olmap_osmlayer>


<olmap_osmlayer id="olmap" name="Cratonic - area model" url="http://tilestream.openquake.org/v2/hazard_AUS14-BR_input_cratonic_area/${z}/${x}/${y}.png" visible="true" attribution="Background and regional cratonic model"></olmap_osmlayer>

<olmap_osmlayer id="olmap" name="Cratonic - point model" url="http://tilestream.openquake.org/v2/hazard_AUS14-BR_input_cratonic_point/${z}/${x}/${y}.png" visible="true" attribution="Background and regional cratonic model"></olmap_osmlayer>

<olmap_osmlayer id="olmap" name="Non-cratonic - area model" url="http://tilestream.openquake.org/v2/hazard_AUS14-BR_input_noncratonic_area/${z}/${x}/${y}.png" visible="true" attribution="Background and regional non-cratonic model"></olmap_osmlayer>

<olmap_osmlayer id="olmap" name="Non-cratonic - point model" url="http://tilestream.openquake.org/v2/hazard_AUS14-BR_input_noncratonic_point/${z}/${x}/${y}.png" visible="true" attribution="Background and regional non-cratonic model"></olmap_osmlayer>



<html>
<div class='my-legend'>
<div class='legend-title'>Total occurrence rate <br> (number of events / year)
<div class='legend-scale'>
  <ul class='legend-labels'>
<li><span style='background:rgb(30, 92, 179);'></span>< 1e-6</li>
<li><span style='background:rgb(25, 181, 241);'></span>1e-6 - 1e-5</li>
<li><span style='background:rgb(0, 255, 255);'></span>1e-5 - 1e-4</li>
<li><span style='background:rgb(100, 229, 50);'></span>1e-4 - 1e-3</li>
<li><span style='background:rgb(255, 255, 0);'></span>1e-3 - 1e-2</li>
<li><span style='background:rgb(252, 199, 7);'></span>1e-2 - 1e-1</li>
<li><span style='background:rgb(255, 128,  0);'></span>1e-1 - 1</li>
<li><span style='background:rgb(255, 0, 0);'></span>1 - 10</li>
<li><span style='background:rgb(255, 0, 255);'></span>>= 10</li>
  </ul>
</div>
</div>
</div>

<style type='text/css'>
  .my-legend .legend-title {
    text-align: left;
    margin-bottom: 5px;
    font-weight: bold;
    font-size: 80%;
    }
  .my-legend .legend-scale ul {
    margin: 0;
    margin-bottom: 5px;
    padding: 0;
    float: left;
    list-style: none;
    }
  .my-legend .legend-scale ul li {
    font-size: 80%;
    list-style: none;
    margin-left: 0;
    line-height: 18px;
    margin-bottom: 2px;
    }
  .my-legend ul.legend-labels li span {
    display: block;
    float: left;
    height: 16px;
    width: 30px;
    margin-right: 5px;
    margin-left: 0;
    border: 1px solid #999;
    }
  .my-legend .legend-source {
    font-size: 70%;
    color: #999;
    clear: both;
    }
  .my-legend a {
    color: #777;
    }
</style>
</html>
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===== The Ground Motion Model =====
The ground motion model distinguishes between two main tectonic regions:
  * Cratonic
  * Non-cratonic
For each tectonic region, the model considers multiple ground motion prediction equations organized in a logic tree structure.

|< 25em 80% >|
| **Cratonic**                | **Weight**  |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/allen_2012.html
|Allen 2012]]                 | 0.3       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/atkinson_boore_2006.html
|Atkinson and Boore 2006]]             | 0.3       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/chiou_youngs_2008.html
|Chiou and Youngs 2008]]                   | 0.1       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/somerville_2009.html
|Somerville et. al. 2009 (for Yilgarn Craton)]]                   | 0.3       |

|< 25em 80% >|
| **Non-cratonic**                | **Weight**  |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/allen_2012.html
|Allen 2012]]                 | 0.25       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/atkinson_boore_2006.html
|Atkinson and Boore 2006]]             | 0.25       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/chiou_youngs_2008.html
|Chiou and Youngs 2008]]                   | 0.25       |
| [[http://docs.openquake.org/oq-hazardlib/stable/gsim/somerville_2009.html
|Somerville et. al. 2009 (Non-cratonic)]]                   | 0.25       |   

=== Reference site condition ===
The reference site condition for the 2012 Australia national seismic hazard map is defined as generic rock assumed to have a Vs30 = 760 m/s. The [[http://docs.openquake.org/oq-hazardlib/stable/gsim/atkinson_boore_2006.html
|Atkinson and Boore 2006]] and the [[http://docs.openquake.org/oq-hazardlib/stable/gsim/chiou_youngs_2008.html
|Chiou and Youngs 2008]] GMPEs accept Vs30 as a prediction variable. The [[http://docs.openquake.org/oq-hazardlib/stable/gsim/allen_2012.html
|Allen 2012]] and [[http://docs.openquake.org/oq-hazardlib/stable/gsim/somerville_2009.html
|Somerville et. al. 2009]] models are instead calibrated for Vs30 equal to 820 m/s and 865 m/s, respectively. For calculation purposes, the default site conditions are assumed consistent with the generic rock conditions.

===== Hazard Results =====

==== Hazard maps ====
The figures below represent hazard maps for peak ground acceleration, for 10% and 2% probability of exceedance in 50 years, as computed by the OpenQuake-engine. Hazard maps are computed following the methodology described by [[australia_2012_intro#References | Burbidge (2012)]]. Separate hazard calculations are done for the background and regional model and for the hot spots model. Where the hot spots model predicts higher hazard level than the background and regional model, the mean of the two is taken.\\
{{:map_au_pga_0.1.png?direct&450|}}
{{:map_au_pga_0.02.png?direct&450|}}

==== Comparison against Geoscience Australia (GA) hazard results ====
The figure below shows the comparison between hazard map values for two return periods (RP) of 500 and 2500 years for the capital cities of Australia. GA reference values were taken from table 2, page 36 in [[australia_2012_intro#References | Leonard et. al. (2013)]].
{{ :ga_oq_hazardmapvalues.png?direct&600 }}
===== References =====
  * Burbidge, D. R. (2012). The 2012 Australian Earthquake Hazard Map. Record  2012/071. Geoscience Australia. Canberra.[[http://www.ga.gov.au/corporate_data/74811/Rec2012_071.pdf |Download .pdf]]
  
  * Leonard, M., Burbidge, D. and Edwards, M. (2013). Atlas of seismic hazard maps of Australia: seismic hazard maps, hazard curves and hazard spectra. Record 2013/41. Geoscience Australia: Canberra.[[http://www.ga.gov.au/corporate_data/77399/Rec2013_041.pdf| Download .pdf]]
 
  * Leonard, M. (2010). Earthquake Fault Scaling: Self-Consistent Relating of Rupture Length, Width, Average Displacement, and Moment Release. Bulletin of the Seismological Society of America, 100(5A), 1971–1988. doi:10.1785/0120090189. [[http://www.bssaonline.org/content/100/5A/1971.abstract | Journal website]]

  * McPherson, A.A. & Hall, L.S., 2007. Development of the Australian National Regolith Site Classification Map. 1 ed. Record  2007/007. Geoscience Australia, Canberra. [[http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_a05f7892-d027-7506-e044-00144fdd4fa6/Development+of+the+Australian+National+Regolith+Site+Classification+Map| Link]]
===== Model Summary Table =====

<wrap info>This table summarises the main characteristics of the original implementation of this model </wrap>

|< 100 5em 60% 40% >|
^ 1          ^ Datasets availability                                                                                                                                                                                                                          ||
| 1.1        | Earthquake catalogue                                                      | Not available. The procedure used to create the catalogue is well described in Chapter 2 of [[australia_2012_intro#References| Burbidge (2012)]]                    |
| 1.2        | Geological database                                                       | A database of faults is available but this hazard model does not include fault sources.                                                                             |
| 1.3        | Strong-motion database                                                    | Not available. In Chapter 5 of [[australia_2012_intro#References| Burbidge (2012)]] there is a comprehensive comparison between candidate GMPEs and recorded data.  |
| 1.4        | Site characterization database                                            | We assume the Regolith map of [[australia_2012_intro#References|McPherson et al. (2007)]] has been used                                                             |
| //Notes//  |                                                                                                                                                                                                                                                ||
|                                                                                                                                                                                                                                                            |||
^ 2          ^ Methodology for model development                                                                                                                                                                                                              ||
| 2.1        | Scientific participation (SSHAC levels) and review process                | Level 2                                                                                                                                                             |
| 2.2        | Documentation describing model preparation                                | See [[australia_2012_intro#References| Burbidge (2012)]]                                                                                                            |
| 2.3        | Codes used for model preparation                                          | Not available                                                                                                                                                       |
| //Notes//  |                                                                                                                                                                                                                                                ||
|                                                                                                                                                                                                                                                            |||
^ 3          ^ PSHA input model                                                                                                                                                                                                                               ||
| 3.1        ^ Seismic Source Model                                                                                                                                                                                                                           ||
| 3.1.1      | Area sources                                                              | Included                                                                                                                                                            |
| 3.1.2      | Grid sources                                                              | Not included                                                                                                                                                        |
| 3.1.3      | Crustal faults                                                            | Not included                                                                                                                                                        |
| 3.1.4      | Subduction faults                                                         | Not included                                                                                                                                                        |
| 3.1.5      | Non-parametric ruptures                                                   | Not included                                                                                                                                                        |
| 3.1.6      | Magnitude-area scaling relationships                                      | [[australia_2012_intro#References| Leonard (2010)]]                                                                                                                 |
| 3.2        ^ Ground Motion Model                                                                                                                                                                                                                            ||
| 3.2.0      | Tectonic regionalisation                                                  | The model defines two tectonic provinces: cratonic and non-cratonic.                                                                                                |
| 3.2.1      | Models for active shallow seismicity                                      | Not explicity included                                                                                                                                              |
| 3.2.2      | Models for subduction interface                                           | Not included                                                                                                                                                        |
| 3.2.3      | Models for subduction intraslab                                           | Not included                                                                                                                                                        |
| 3.2.4      | Models for stable continental regions                                     | Included                                                                                                                                                            |
| 3.2.5      | Models for deep non-subduction sources                                    | Not included                                                                                                                                                        |
| 3.2.6      | Models for volcanic areas                                                 | Not included                                                                                                                                                        |
| 3.3        ^ Site Response Model                                                                                                                                                                                                                            ||
| 3.3.1      | Based on GMPEs                                                            | Yes, hazard is computed for a reference soil condition corresponding to NEHRP B/C boundary (Vs30=760 m/s)                                                           |
| 3.3.2      | Based on site-response analysis                                           | No                                                                                                                                                                  |
| 3.4        ^ Epistemic uncertainties                                                                                                                                                                                                                        ||
| 3.4.1      | Seismic Source Model                                                      | Not explicitly included (Mmax determined by weighted average of three studies).                                                                                     |
| 3.4.2      | Ground Motion Model                                                       | Included using a logic tree (see  [[australia_2012_intro#the_ground_Motion_model| the ground motion model]] section)                                                |
| 3.4.3      | Site Response Model                                                       | Not included                                                                                                                                                        |
| //Notes//  |                                                                                                                                                                                                                                                ||
|                                                                                                                                                                                                                                                            |||
^ 4          ^ Hazard Input Description                                                                                                                                                                                                                       ||
| 4.1        | Hazard input document                                                     | Not avaliable                                                                                                                                                       |
| 4.2        | Input files                                                               | Not available                                                                                                                                                       |
| //Notes//  |                                                                                                                                                                                                                                                ||
|                                                                                                                                                                                                                                                            |||
^ 5          ^ Calculation                                                                                                                                                                                                                                    ||
| 5.1        | Software                                                                  | GA’s Earthquake Risk Model (EQRM)                                                                                                                                   |
| //Notes//  | The EQRM sofware can be downloaded [[http://eqrm.sourceforge.net/|here]]                                                                                                                                                                       ||
| 5.2        ^ Results                                                                                                                                                                                                                                        ||
| 5.2.1      | Hazard curves                                                             | Available for the major cities                                                                                                                                      |
| 5.2.2      | Hazard maps                                                               | Available                                                                                                                                                           |
| 5.2.3      | Uniform hazard spectra                                                    | Available for the major cities                                                                                                                                      |
| 5.2.4      | Disaggregation                                                            | Not available                                                                                                                                                       |
| 5.2.5      | Stochastic event sets                                                     | The methodology adopted for the calculation of hazard uses stochastic event sets but these are not presented as results of the analysis                             |
| 5.2.6      | Ground motion fields                                                      | As per "stochastic event sets"                                                                                                                                      |
| //Notes//  |                                                                                                                                                                                                                                                ||



===== Download The OpenQuake-engine Input Model =====

The OpenQuake-engine input model (NRML format) can be downloaded at the link provided below - Please read the license and disclaimer attached to the model.                                                                                                                                                                                                                                          

<color red/white> N.B. This is a model adapted by GEM Hazard Team to the OpenQuake-engine from the original model developed by Geoscience Australia. This explains minor differences you might encounter between the results presented in the OpenQuake platform and those disseminated by the original Organisation. </color>

[[ https://platform.openquake.org/documents/123 | Download]]