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This page has descriptions of the file formats that we use in various places.

Table of Contents

SRF

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The .info files that accompany .srf files are in HDF5 format. The filenames match with the exception of the extension.

All information is stored as attributes.

There are 4 types of SRF files that can be created, all SRF files are created directly or indirectly via createSRF.py.

Type 1	point source. appears as 1 plane with 1 subfault.
Type 2	finite fault. a single plane created from point source attributes, it has an are determined by a magnitude scaling relation.
Type 3	finite fault. a single plane created with specified parameters.
Type 4	finite fault. a multiple plane fault. planes can be internally generated together and cut up (like plane extensions that continue at a different strike angle) or: separate cases where multiple SRFs are combined. where separate cases are used, each can have a delay time to synchronise rupture initiation time between cases.

Common Attributes (always available)

attribute	description
type	1: point source, 2: finite fault from point source info, 3: single plane, 4: multiple plane
dt	slip time step (s)
rake	rake angles (type 1-3: single value, type 4: 2D list for cases, fault planes)
mag	magnitude (type 1-3: single value, type 4: list for each case)
hlon	hypocentre longitude for first fault (degrees)
hlat	hypocentre latitude for first fault (degrees)
hdepth	hypocentre depth for first fault (km)
corners	4 corners (longitude, latitude) for each plane. derived parameter (shape of array is nplane, 4 corners, 2 lonlat values).

SRF Plane Attributes (lists with a length matching number of fault planes)

naming taken from qcore/srf.py

attribute	description
centre	top centre longitude, latitude
nstrike	number of subfaults along strike
ndip	number of subfaults along dip
length	length (along strike) of fault plane (km)
width	width (along dip) of fault plane (km)
strike	strike angle (degrees)
dip	dip angle (degrees)
shyp	hypocentre location along strike from top centre (km), -999.9 for plane extentions
dhyp	hypocentre location along dip from top edge (km), -999.9 for plane extentions
dtop	depth of top edge (km)
dbottom	depth to bottom of plane, derived parameter (km)

Type 1 (point source) Attributes

attribute	description
vs	v_s at centroid depth (km/s)
rho	density

Type 2 (finite fault from point source data) Attributes

attribute	description
mwsr	magnitude scaling relation name
cd	centroid depth (km)

Type 2+ (finite faults) Attributes

attribute	description
vm	velocity model used (basename)
shyp0	distance along strike (km) to hypocentre for each case from top left corner (strike = 0, dip = 0)
dhyp0	distance along dip (km) to hypocentre for each case from top left corner (strike = 0, dip = 0)

Optional Attributes (need to check if they exist)

attribute	description
tect_type	tectonic type, taken from the NHM file in nhm2srf.py. known options: ACTIVE_SHALLOW VOLCANIC SUBDUCTION_INTERFACE

Format

https://strike.scec.org/scecpedia/Standard_Rupture_Format
SRF-Description-Graves_2.0.pdf
SRF File Format Version 1 (output of genslip): srf_description_version_1.pdf
Details on Source Modelling : Source Modelling for GMSim

SRF info format

The .info files that accompany .srf files are in HDF5 format

Example (CBalleny.info)

Image Added

Stoch format

Image Added

LF/HF/BB binary format

These files store timeseries data. All formats follow a style derived from the LF seis format produced by EMOD3D:

...

HF and BB have gaps between the first 2 sections to allow future additions to section 1 without breaking backwards compatibility.

LF

HF

BB

i4 number of stations

TOTAL 4 BYTES

i4 number of stations
i4 number of timesteps
i4 seed used in simulation
i4 site amplification used (bool)
i4 path duration method

0: GP2010 formulation
1: WUS modification trial/error
2: ENA modification trial/error
11: WUS formulation of BT2014
over predicts for multiple rays
12: ENA modification trial/error
over predicts for multiple rays

i4 number of ray methods
known options for first-fourth type below:

1: direct
2: moho

i4 first ray method used
i4 second ray method used
i4 third ray method used
i4 fourth ray method used
i4 nbu parameter
i4 ift parameter
i4 nlskip parameter
i4 icflag parameter (bool)
i4 individually run stations (bool)
i4 site specific VMs used (bool)
f4 duration of timeseries (s)
f4 timestep of timeseries (s)
f4 start time of timeseries (s)
f4 stress drop average (bars)
f4 kappa parameter
f4 q frequency exponent
f4 max sim frequency (Hz)
f4 flo parameter (Hz)
f4 fhi parameter (Hz)
f4 rupture velocity factor (rupture : Vs)
f4 rvfac shallow fault multiplier
f4 rvfac deep fault multiplier
f4 czero coefficient, -1: used binary default
f4 calpha coefficient, -1: used binary default
f4 seismic moment, -1: used rupture model
f4 rupture velocity, -1: used rupture model
f4 depth to moho, -1: used binary default (999.9)
f4 vp_sig parameter
sig parameters are likely uncertainties
f4 vsh_sig parameter
f4 rho_sig parameter
f4 qs_sig parameter
f4 fourier amplitude uncertainty (1)
f4 fourier amplitude uncertainty (2)
f4 rupture velocity uncertainty
s64 stoch file used (basename)
s64 velocity model used (basename)

TOTAL 288 BYTES

i4 number of stations
i4 number of timesteps
f4 duration of timeseries (s)
f4 timestep of timeseries (s)
f4 start time of timeseries (s)
s256 LF directory path used
s256 LF VM directory path used
s256 HF file path used
possibly add vsite file path used here?

TOTAL 788 BYTES

START OFFSET 4 BYTES

i4 index of station in input file
i4 x gridpoint of station
i4 y gridpoint of station
i4 z gridpoint of station
i4 simulation number of timesteps
f4 simulation timestep (s)
f4 simulation grid spacing (km)
f4 simulation grid rotation (degrees)
f4 latitude of station (degrees)
f4 longitude of station (degrees)
s8 name of station

TOTAL 48 BYTES * NUM_STATIONS

START OFFSET 512 BYTES

f4 longitude of station (degrees)
f4 latitude of station (degrees)
s8 name of station
f4 epicentre distance to station (km)
f4 vs30 at station (m/s)

TOTAL 24 BYTES * NUM_STATIONS

START OFFSET 1280 BYTES

f4 longitude of station (degrees)
f4 latitude of station (degrees)
s8 name of station
i4 x gridpoint of station
i4 y gridpoint of station
i4 z gridpoint of station
f4 epicentre distance to station (km)
f4 HF

vs30

vs30ref (m/s)
f4 LF

vs30

vs30ref (m/s)
f4 BB vs30 (m/s)

TOTAL 44 BYETS * NUM_STATIONS

START OFFSET 0 FROM ABOVE

f4 velocity (cm/s) timeseries in array dimensions:
timestep, station, component (x, y, z, ..., 9)

TOTAL 4 BYTES * PRODUCT_OF_DIMENTIONS

START OFFSET 0 FROM ABOVE

f4 acceleration (cm/s^2) timeseries in array dimensions:
station, timestep, component (x, y, z)

TOTAL 4 BYTES * PRODUCT_OF_DIMENTIONS

START OFFSET 0 FROM ABOVE

f4 acceleration (g) timeseries in array dimensions:
station, timestep, component (x, y, z)

TOTAL 4 BYTES * PRODUCT_OF_DIMENTIONS

XYTS.e3d binary format

This file is produced by EMOD3D and contains a timeseries of ground motions on the XY plane. Unlike the LF seis files, this contains data at all grid points and may have a decimated resolution specified when running EMOD3D through the e3d.par file with the parameters dxts and dyts.

...

simulation metadata
1. INTEGERS
  1. number of first x gridpoint
  2. number of first y gridpoint
  3. number of first z gridpoint
  4. number of first timestep
  5. number of x gridpoints
  6. number of y gridpoints
  7. number of z gridpoins (always 1 by definition of X-Y file)
  8. number of timesteps
2. FLOATS
  1. x spacing between given gridpoints (km)
  2. y spacing between given gridpoints (km)
  3. original (pre-decimated) grid spacing between gridpoints used in simulation (km)
  4. timestep in timeseries (s)
  5. model rotation of gridpoints (degrees)
  6. model centre latitude (degrees)
  7. model centre longitude (degrees)
timeseries
- float array of velocities in the dimentions of timesteps, components (x, y, z), y grid positions, x grid positions.

Intensity Measure calculation

The IM calculation code will produce a number of text files (decided as of 25/05/2018). We will summarize them in the following.

...

Code Block
station, component, IM_1, IM_2, ...., IM_N

Empirical IMs

As above the empirical intensity measures have a similar format:

Code Block
station, component, IM_1, IM_1_sigma, IM_2, IM_2_sigma, ...., IM_N, IM_N_sigma

Notes: 1) the component for empirical IMs is always 'geom' 2) only total sigma is saved to the csv file

Rrup file

The file format for this is:

...

Code Block
identifier, rupture, type, date, version

GSF File

The GSF file is used to define the geometry of a source in a source modelling problem. It is the first step in the SRF generation process after a realisation is read.

A GSF file contains three sections in order:

Errata/Header section,
Declaration of the number of points (N),
The geometry description: N lines representing each point in the geometry.

There are utilities to read GSF files in the gsf module within qcore.

Errata/Header

The header consists of a number of commented lines, each beginning with # . Here is an example:

Code Block
# nstk= 179 ndip= 215 # flen= 17.0720 fwid= 21.2853 # LON LAT DEP(km) SUB_DX SUB_DY LOC_STK LOC_DIP LOC_RAKE SLIP(cm) INIT_TIME SEG_NO

This is the typical output of fault_seg2gsf . The first line has the number of points in the strike and dip directions, respectively. Then the length and width of the fault, and the last line is a description of each column in the points section.

The header is skipped by programs parsing GSF files and may contain any number of lines. The Python GSF generator, for example, only prints out the column description.

Code Block
# LON LAT DEP(km) SUB_DX SUB_DY LOC_STK LOC_DIP LOC_RAKE SLIP(cm) INIT_TIME SEG_NO

Declaration of the Number of Points

Immediately following the header, there is one line containing the number of points in the GSF geometry definition.

Geometry Description

The geometry description has N lines, where N is the number of points declared in the previous section. Each line has 11 space separated values representing one point in the geometry.

Column	Description
LON	The longitude of the point.
LAT	The latitude of the point.
DEP	The depth of the point (in kilometres, with -10 meaning 10km below ground level).
SUB_DX	The subdivision length in the strike direction.
SUB_DY	The subdivision length in the dip direction.
LOC_STK	The fault segment strike.
LOC_DIP	The fault segment dip.
LOC_RAKE	The fault segment rake.
SLIP	The total slip at this point (cm), usually -1.
INIT_TIME	The initial rupture time of this point, usually -1.
SEG_NO	The number corresponding to the segment this point belongs to.:

Child pages

Versions Compared

Old Version 42

New Version 60

Key

SRF

Common Attributes (always available)

SRF Plane Attributes (lists with a length matching number of fault planes)

Type 1 (point source) Attributes

Type 2 (finite fault from point source data) Attributes

Type 2+ (finite faults) Attributes

Optional Attributes (need to check if they exist)

Format

SRF info format

Stoch format

LF/HF/BB binary format

XYTS.e3d binary format

Intensity Measure calculation

Empirical IMs

Rrup file

GSF File

Errata/Header

Declaration of the Number of Points

Geometry Description