Scenario ShakeMap Calculations
This page explains how to use OpenSHA's Scenario-ShakeMap application to reproduce the images in Figure 1 of the paper:
Loss Estimates for a Puente Hills Blind-Thrust Earthquake in Los Angeles, California
By Edward H. Field, Hope A. Seligson, Nitin Gupta, Vipin Gupta, Thomas H Jordan, and Kenneth W. Campbell
Earthquake Spectra 21, 329-338.
Re-prints are available upon request.
In addition to reproducing the images in Figure 1, this page also explains some other features of our scenario shakemap application.
You will need an internet connection to follow these instructions.
First, download the application at the following link:
Note to Mac/Safari users: you must right-click the Jar-file link below (or hold down the option key if your mouse only has one button), otherwise the Jar-file contents will be shown in a browser window (not a pretty site)
Now launch the application by double clicking (on Mac or Windows) or by launching from the command line as follows:
java -jar ScenarioShakeMapApp.jar
Read the section “How to Run Java Applications” if you have problems.
Reproducing Figure 1A:
1) Under the "Intensity-Measure Relationship" tab, choose "PGA" from the "IMT" menu, and then choose "Abrahamson & Silva (1997)" from the "IMR" menu.
2) Under the "Region and Site Params" tab, set the following as:
"Min Longitude" = -119
"Max Longitude" = -117
"Min Latitude" = 33.5
"Max Latitude" = 34.5
"Grid Spacing" = 0.016667
"Set Site Params" = "Use both CGS and SCEC Basin Depth (web services)"
"Default AS Site Type" = "Deep Soil"
3) Under the "Earthquake Rupture" tab set the following:
"Select Method of Getting Eqk Rupture" = "Custom Eqk Rupture"
"Rupture Type" = "Finite source rupture"
"Magnitude" = 7.2
"Rake (degrees)" = 90Now click "Set Fault Surface" & set the following
"Grid Spacing (km)" = 1.0
"Num. of Fault Trace Points" = 4Click "Fault Latitudes" and enter the following:
Lat-1 (Degrees) = 33.9451
Lat-2 (Degrees) = 33.9423
Lat-3 (Degrees) = 33.9746
Lat-4 (Degrees) = 34.0768
(click "Update Latitudes" when done)Likewise for "Fault Longitudes":
Lon-1 (Degrees) = -117.8679
Lon-2 (Degrees) = -118.0315
Lon-3 (Degrees) = -118.1253
Lon-4 (Degrees) = -118.3194"Num. of Dips" = 1
Click "Dips" and set it as 27 degrees
Click "Depths" and set:
"Depth-1 (km)" = 5.0
"Depth-2 (km)" = 17.0"Finite Fault Type" = "Stirling"
"Ave Dip Direction (degrees) " = leave this blank (so direction is perpendicular to ave strike)
Now click "Make Simple Fault" at the bottom
Finally, leave "Set Hypocenter Location" un-selected
4) Click the "Exceedance Level/Probability" tab and set:
"Map Type" = IML@Prob
"Probability" = 0.5
These settings will give us a map of the median intensity-measure level (IML).
5) Click the "Map Attributes" tab and set the following:
"Color Scheme" = "MaxSpectrum.cpt"
"Color Scale Limits" = "Manually"
"Color-Scale Min" = 0.0
"Color-Scale Max" = 1.0
"Topo Resolution (arc-sec)" = "18"
"Highways in plot" = "None"
"Coast" = "Draw & Fill"
"Image Width (inches)" = 6.5
"Use GMT WebService" must be selected (check the box)
"Plot Log" should NOT be selected
"Generate Hazus Shape Files" should not be selected
"Rupture-Surface Plotting" = "Draw Perimeter"
6) Now click "Make Map" at the bottom of the application and you should see Figure 1A in a few seconds.
Reproducing Figure 1B:
(assuming you've done the above)
Click the "Earthquake Rupture" tab, change the Magnitude to 7.5, click "Make Map" at the bottom, and in a few seconds you should see Figure 1B.
Reproducing Figure 1C:
(assuming you've done the above)
Change the Magnitude back to 7.2.
Click the "Intensity-Measure Relationship" tab and change the IMR parameter to "Boore, Joyner,& Fumal (1997)".
After clicking "Make Map" at the bottom you should see Figure 1C.
Reproducing Figure 1D:
(assuming you've done the above)
Click the "Earthquake Rupture" tab, change the Magnitude to 7.5, click "Make Map" at the bottom, and you should see Figure 1D.
Reproducing Figure 1E:
(assuming you've done the above)
Click the "Intensity-Measure Relationship" tab and change the IMT parameter to "SA" and the "SA Period" parameter to 1.0. Also change the IMR parameter to "Abrahamson & Silva (1997)".
Now click the "Map Attributes" tab and change the "Color-Scale Max" parameter to 2.11.
Click "Make Map" and you should see Figure 1E.
NOTE - the PGV calculations in the paper assume that PGV is proportional to 1-sec SA according to the Newmark Hall (1982) relationship:
1-sec SA = 1.056 PGV (SI units)
Therefore, the SA plot just made is identical to the PGV plot in the paper.
Reproducing Figure 1F:
Click the "Intensity-Measure Relationship" tab and change the IMR parameter to "Field (2000)".
Clicking "Make Map" produces the final image in the plot (Figure 1F).
Why do the Images Look Different?:
The slight color differences are due to resolution & image-format differences between the figure for the paper and the images generated here.
The labeling and scale-format differences are due to post processing (touching up) done with Adobe Illustrator to make the figure for publication.
By the way, a PostScript version of the plots you made, as well as the GMT scripts and data files, are available for download; just scroll to the bottom of the window below each plot to see the download link. This allows you to edit the PostScript files.
What's the Difference Between the "Stirling" and "Frankel" Finite Fault Types?:
The best way to see this is to compare the difference.
First, click on the "Map Attributes" tab and change the "Rupture-Surface Plotting" parameter to "Draw Discrete Points".
Then click the "Earthquake Rupture" tab, click "Set Fault Surface", set the "Grid Spacing" parameter to 2.0, and then click the "Make Simple Fault" button at the bottom.
Now clicking the "Make Map" should show you the map made previously but with a discretized version of the fault surface (rather than the outline of the fault being drawn).
This is the "Stirling" fault representation (where depth contours are parallel to the trace of the top of the fault).
Now click "Set Fault Surface" again, change the "Finite Fault Type" parameter to "Frankel's", and then click the "Make Simple Fault" button at the bottom.
Clicking the "Make Map" shows that Frankel's representation projects a rectangle down perpendicular to the local strike along the fault.
What is the Other Way of Selecting an Earthquake Rupture?:
Besides creating a custom earthquake rupture (what we did above), you can also choose one from any available Earthquake Rupture Forecast (ERF).
To exemplify, let compute a Scenario ShakeMap for one of the Puente Hills ruptures defined in the ERF used to make our National Hazard Maps.
Click the "Earthquake Rupture" tab, and under "Select method of getting Eqk Rupture" choose "Select EqkRupture from an ERF".
Under "Eqk Rup Forecast" choose "USGS/CGS 2002 Adj. Cal. ERF", and in the window that pops up click "Update Forecast" at the bottom.
Under "Source Index" choose source # 136 - their Puente Hills Characteristic source.
Each source can have multiple ruptures (i.e., difference magnitudes and/or rupture locations on the fault), so you need to give a Rupture Index as well (info on each is given below). Choose one and click "Make Map".
You might want to go back and select "Draw Perimeter" from the "Rupture-Surface Plotting" under the "Map Attributes" tab, otherwise you won't be able to see the shaking levels directly over the fault.
How to Generate HAZUS Shape Files:
Choose "Generate Hazus Shape Files for Scenario" from the "Control Panels" menu, read the text, and click the button.
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