Cascadia Simulations
Daniel Roten, Kim Olsen have used AWP-ODC-GPU software to run simulations of large magnitude earthquakes in the Cascadia region.
Contents
Cascadia M9.2
- Daniel Roten recently ran a simulation of a M9.2 Cascadia earthquake on Summit, to compare ground motions against the previous Titan simulations, using 375 V100 GPUs for 3:30 hrs.
- These data are on OLCF Summit in the Alpine file system:
/gpfs/alpine/proj-shared/geo112/rotend/Cascadia.alpine/scen_13_a_S_66m_dm_summit_flt/output_sfc
Simulation Surface Ground Motion Timeseries
- Deterministic 1Hz ground motion data:
- 3 components x 343 datafiles per component
- 22TB of simulation output surface velocity data on a dense grid
Broadband ground motion data
A selected subset of the M9.2 velocity timeseries were processed to add stochastic high frequencies to the ground motions. These broadband ground motion data are available for use for a smaller region, on a less dense grid.
Format Description
- The sampling interval in the output is 40 ms (250 samples per second).
- The total simulation duration is 450 seconds.
- The time step used in the finite difference simulation was 4 ms, and 102,000 time steps were computed.
- The output files are binary, and contain ground velocities (m/s) as
32-bit floating point numbers.
- There is no file header.
- Each component is saved in separate files, and the data are aggregated
in files containing 100 time steps.
- The naming convention is S%c_0_%07d, where the character stands for the component (X, Y or Z), the 7-digit number for the last time step in the file (e.g., 1000 for the first file, and 102,000 for the last one).
- Inside each binary file, X increases fastest, followed by Y, and time t increasing slowest.
Simulation Configuration File
The AWP-ODC-GPU IN3D configuration file used on Summit to run the M9.2:
(base) [pmaech@login5.summit scen_13_a_S_66m_dm_summit_flt]$ more IN3D.out 448.001 TMAX = propagation time 66.6666667 DH = spatial step for x, y, z (meters) 0.004 DT = time step (seconds) 0 NPC = PML or Cerjan ABC (1=PML, 0=Cerjan) 10 ND = ABC thickness (grid-points) PML <= 20, Cerjan >= 20 0.95 ARBC = coefficient for PML (3-4), or Cerjan (0.90-0.96) 0.0 PHT = M-PML coefficient 25600 NSRC = number of source nodes on fault 2400 NST = number of time steps in rupture functions 9720 NX = x model dimension in nodes 16065 NY = y model dimension in nodes 80 NZ = z model dimension in nodes 2 NPX = number of procs in the x direction 2 NPY = number of procs in the Y direction 1 NPZ = number of procs in the Z direction 2 IFAULT = mode selection and fault or initial stress setting 0 CHECKPOINT = checkpoint at step 1 ISFCVLM = output options, surface and volume output 0 IMD5 = MD5 output option 1 IVELOCITY = output accumulation option 1 MEDIARESTART = initial media restart option 8 NVAR = number of variables in a grid point 1 IOST = max amount of reader (RANKSIZE/IOST) 1 PARTDEG = further XY plane partitioning when mediarestart=2 1 IO_OPT = output data on/off option 1 PERF_MEAS = performance timing measurement on/off 1 IDYNA = mode selection of dynamic rupture model 1 SOCALQ = (or NEG_LAMBDA) Southern California Vp-Vs Q relationship enabling flag 1 NVE = visco or elastic scheme (1=visco, 0=elastic) 0.0 MU_SS = cohesion 0.12 MU_DD = dynamic friction coefficient (not used) 0.005 FL = Q bandwidth low frequency 1200.0 FH = Q bandwidth high frequency 1.0 FP = Q bandwidth central frequency 10 READ_STEP 100 WRITE_STEP 10 WRITE_STEP2 1 NBGX = first x node to contain receivers 9720 NEDX = last x node to contain receivers 1 NSKPX = skip of nodes containing x receivers 1 NBGY = first y node to contain receivers 16065 NEDY = last y node to contain receivers 1 NSKPY = skip of nodes containing y receivers 1 NBGZ = first z node to contain receivers 1 NEDZ = last z node to contain receivers 1 NSKPZ = skip of nodes containing z receivers 10 NTISKP = time skip of seismograms (every nth step) 1 NBGX2 = first x node to contain receivers 192 NEDX2 = last x node to contain receivers 1 NSKPX2 = skip of nodes containing x receivers 1 NBGY2 = first y node to contain receivers 192 NEDY2 = last y node to contain receivers 1 NSKPY2 = skip of nodes containing y receivers 1 NBGZ2 = first z node to contain receivers 192 NEDZ2 = last z node to contain receivers 1 NSKPZ2 = skip of nodes containing z receivers 2 NTISKP2 = time skip of seismograms (every nth step) 'output_ckp/chkp' CHKP = input and derived parameters for QC 'output_ckp/chkj' CHKJ = single location output for QC 'sliprate.dat' INSRC = mt based fault file 'SAF_dyn_50m_test+idx' INVEL = velocity structure file 'output_sfc/SX_0_' SXRGO = x regular-grid volume/time output 'output_sfc/SY_0_' SYRGO = y regular-grid volume/time output 'output_sfc/SZ_0_' SZRGO = z regular-grid volume/time output 'output_vlm/VX' SXRGO2 = regular-grid slip/time output 'output_vlm/VY' SYRGO2 = regular-grid sliprate/time output 'output_vlm/VZ' SZRGO2 = regular-grid rupture output 'output_dyn/SGSN' SGSN = file to host 19 more variables for SGSN mode 0 OFASTT = output format: on(1)/off(0) fast
Metadata
Metadata for the Cascadia M9.2 simulation data
- Points in X: 9,720
- Points in Y: 16,065
- Resolution along X and Y: 66.666 m
- The projection is UTM for zone 10. There is no rotation, with the X
axis pointing from west to east and the Y axis from south to north.
- The UTM coordinates for the X and Y axis are given in the two attached
ASCII files.
- The sampling interval in the output is 40 ms (250 samples per second).
- The total simulation duration is 448 seconds.
- The time step used in the finite difference simulation was 4 ms, and
102,000 time steps were computed.
- The output files are binary, and contain ground velocities (m/s) as
32-bit floating point numbers.
- There is no file header.
- Each component is saved in separate files, and the data are aggregated
in files containing 100 time steps.
- The naming convention is S%c_0_%07d, where the character stands for the component (X, Y or Z), the 7-digit number for the last time step in the file (e.g., 1000 for the first file, and 102,000 for the last one).
- Inside each binary file, X increases fastest, followed by Y, and time t increasing slowest.
Animations:
Daniel Roten created a sample visualization done from a similar simulation (same resolution, but different scenario), which you might want to share along with the data:
Cascadia M9.0
A previous version of data for a magnitude 9.0 was posted on Rhea/Titan in the directory:
/lustre/atlas/proj-shared/geo112/rotend/Cascadia/scen_8_a_N_66m_dm/output_sfc