Fault System Solution Zip File Format Documentation

UCERF3 (and potentially other forecast) data is stored in a zip file format, this page describes how to parse these zip files. If you are using Java, a parser is already written in OpenSHA via the scratch.UCERF3.utils.FaultSystemIO class.

File Formats Used

You must write a parser for each of the following file formats in order to load in a fault system solution.

Double array binary file

These files contain an array of double values in a binary format. These files simply contain a series of big endian 8 bit double precision floating point numbers. The size of this file will be equal to the number of values x 8 bits.

Integer array list binary file

These files contain a list of integer arrays in a binary format. All file entries are 4-bit big endian integer values. The first value in the file is the number of integer arrays stored in the file. Then each array is written to the file by first writing the number of elements in the array, then each value in the array. For example, consider the following 3 arrays:

[ 0 6 2 4 ]
[ 3 6 2 ]
[ 3 7 9 1 4 7 ]

This would be written as (all stored as big endian 4-bit integers):

3 4 0 6 2 4 3 3 6 2 6 3 7 9 1 4 7

In this example, the number of arrays is in red, each array's size in blue, and array data is in black.

Fault section data XML file

Each fault subsection is stored in an XML file, an example of which is shown below.

<?xml version="1.0" encoding="UTF-8"?>

<OpenSHA>
  <FaultSectionPrefDataList>
    <!--- Each fault subsection is listed in it's own element so ensure correct ordering.
Each subsection element name will be i0, i1, i2, ... i[N-1] for N subsections. Note that
some fields may be NaN for certain solutions. -->
    <i0 sectionId="0" sectionName="Los Alamos extension, Subsection 0" aveLongTermSlipRate="NaN"
slipRateStdDev="0.0" aveDip="30.0" aveRake="NaN" aveUpperDepth="0.0" aveLowerDepth="12.0"
aseismicSlipFactor="0.1" couplingCoeff="1.0" dipDirection="205.15857"
parentSectionName="Los Alamos extension" parentSectionId="780" connector="false">
      <!-- This defines a polygon representing the geologic fault zone. Note that UCERF3 uses
a combination of this polygon and a buffered fault trace as described in UCERF3 Appendix O. -->
      <ZonePolygon name="Unnamed Region">
        <LocationList>
          <Location Latitude="34.562639" Longitude="-119.867803" Depth="0.0"/>
          <Location Latitude="34.54856" Longitude="-119.878996" Depth="0.0"/>
          <Location Latitude="34.586297" Longitude="-119.926461" Depth="0.0"/>
          <Location Latitude="34.630493" Longitude="-120.091308" Depth="0.0"/>
          <Location Latitude="34.647866" Longitude="-120.086651" Depth="0.0"/>
          <Location Latitude="34.60288" Longitude="-119.919064" Depth="0.0"/>
        </LocationList>
      </ZonePolygon>
      <!-- This is the actual fault trace. Note that order is important and should follow the
Aki-Richards definition -->
      <FaultTrace name="Los Alamos extension 1">
        <Location Latitude="34.63918" Longitude="-120.08897999999999" Depth="0.0"/>
        <Location Latitude="34.608190666873426" Longitude="-119.97328407378366" Depth="0.0"/>
      </FaultTrace>
    </i0>
    <i1 sectionId="1" ...>
        ...
    </i1>
    ...
    <i[N-1] sectionId="[N-1]" ...>
        ...
    </i[N-1]>
  </FaultSectionPrefDataList>
</OpenSHA>