CyberShake Rupture Files

CyberShake uses rupture files to provide descriptions of rupture geometry, and, in some cases, slip information about individual events to be simulated. A description of these files is below.

UCERF2 files

To date, all CyberShake simulations have been performed using UCERF 2 events. These events can include both a rupture geometry file and a Standard Rupture Format (SRF) description of the event itself.

UCERF2 Rupture Geometry Files

Rupture geometry files contain a list of all the points which appear on the surface of the rupture. This information is needed to determine which SGTs should be saved (so that we have an SGT for each point on every rupture surface), and to generate a rupture variation when passed into the RupGen-api code. We can also use the rupture geometry to generate the list of points we need SGTs for when doing post-processing. Since 2014, we have tried to replace the SRF with the rupture geometry whenever possible, as it is a much smaller file and therefore reduces I/O.

The format of the rupture geometry files is:

Probability = <prob>
Magnitude = <mag>
GridSpacing = <spacing between elements, in km>
NumRows = <# rows>
NumCols = <# cols>
#   Lat         Lon         Depth      Rake    Dip     Strike


...


...

A 'row' is defined as a set of rupture points all at the same depth, and rows are listed in the file from shallowest to deepest.

For ERF 35, we used 1 km spacing; this should be used with 0.5 Hz simulations. For ERF 36, we used 200 m spacing; this should be used with 1 Hz simulations.

These files are stored in <CyberShake root>/ruptures/Ruptures_erf<ERF ID>/<src ID>/<rup ID>/<src>_<rup>.txt. The path to the top-level ruptures directory is specified in cybershake.cfg, and the substructure is assumed in the PreSgt code.

The geometry files for ERF 35 and ERF 36 are available here: ERF 35(127 MB) and here: ERF 36(3.9 GB)

Rupture Variation files

Initially, we precomputed rupture variations for all events and saved these to disk. This was done for the Graves & Pitarka (2006) (Rupture Variation Scenario ID 3) and Graves & Pitarka (2010) (Rup Var Scenario ID 4). These SRFs can be found on SCEC disks at /home/rcf-104/CyberShake2007/ruptures/RuptureVariations_35_V2_3 (Rup Var Scenario ID 3) and /home/rcf-104/CyberShake2007/ruptures/RuptureVariations_35_V3_2 (Rup Var Scenario ID 4), using the same <src id>/<rup id> directory hierarchy as the rupture geometry files.

Starting in 2012, we stopped writing out all the SRFs. Instead, they are generated on-demand in memory during the post-processing. However, these files can still be generated by calling the _write_srf() function in genslip. They follow the SRF format; version 1 is documented here and version 2 here.

RSQSim files

As part of a new effort for 2018, we are proposing to generate CyberShake curves using ruptures generated from RSQSim.

RSQSim Rupture Geometry files

Rupture geometry files generate from RSQSim ruptures have a different header, as the rupture points are on a tetrahedral grid instead of an evenly spaced rectangular one, and so GridSpacing, NumRows, and NumCols don't really translate. Instead, the file format is:

Probability = 5.325298E-6
Magnitude = 7.305054
AveArea = <average area of fault element>
NumPoints = <total number of points>
#   Lat         Lon         Depth      Rake    Dip     Strike
<data for point 0>
<data for point 1>
...
<data for point P>

No order should be assumed for the points.

These files will use the same directory structure (<CyberShake root>/ruptures/Ruptures_erf<ERF ID>/<src ID>/<rup ID>/<src>_<rup>.txt).

RSQSim SRFs

RSQSim SRFs are in version 1 format. The optional "PLANE" section is omitted, since planes don't really map well to RSQSim faults.