UCERF3-ETAS File Formats

Binary Simulation Result, Single Simulation/Catalog

ETAS results are stored in a big-endian binary format for efficiency. The format is as follows:

First a 6-byte header

Data type Name Description
2-byte short int version File format version identifier to accomodate future versions. Currently always '1'
4-byte int num ruptures Total count of rupture records to follow

70-byte rupture records (one for each rupture)

Data type Name Description
4-byte int event ID Unique ID number for the event
4-byte int parent ID ID of the parent for this event, or -1 if spontaneous
2-byte short int generation Generation for this event. 0 means spontaneous
8-byte long origin time Origin time in epoch milliseconds: time since 1/1/1970 GMT
8-byte double latitude Hypocenter latitude in degrees
8-byte double longitude Hypocenter longitude in degrees
8-byte double depth Hypocenter depth in km
8-byte double mag Magnitude
8-byte double dist to parent Distance to parent event, or NaN if spontaneous
4-byte int nth ERF index Internal index for UCERF3-ETAS ERF
4-byte int FSS index Index of UCERF3 Fault System Solution rupture, or -1 if gridded event
4-byte int grid node index Grid node index for Fault System Solution gridded ruptures

Binary Simulation Results, Multiple Simulations/Catalogs

The format for multiple simulations is the same, except it starts with a single integer:

Data type Name Description
4-byte int num catalogs Number of simulations/catalogs present in this file

It is then followed by the "Single Simulation/Catalog" format for each catalog.