The purpose of this page is to provide software for generating synthetic time series of mid-west earthquakes for use by Mid-America Earthquake Center investigators. Because of the lack of strong motion data for M > 5 earthquakes in the region, synthetic time series are generated using band-limited white-noise stochastic simulations and random vibration theory. Tools are provided to investigators to generate the data files require to run Boore's SMSIM programs.
Boore's SMSIM package provides two useful programs, td_drvr to generate actual time series and rv_drvr which uses random vibration theory to estimate peak motions. Since the SMSIM package is a general purpose research tool, we have created a program dorvt180 to create a standard set of parameter files for use by investigators. We do not want center investigators to create arbitrary motions, since there must be an internal consistency with hazard mapping input and results
We thus provide a restricted set of permitted ground motion models:
| Model | Name | Source | Wave Propagation | Site Effect |
| 1 | Atkinson-Boore 1995 (AB95) | AB95 | AB95 | ENA Hard rock |
| 2 | USGS 1996 | USGS 96 150 bar | USGS 96 (same as AB95) |
Generic B-C Boundary |
| 3 | USGS 1996 (modified) |
USGS 96 150 bar | USGS 96 (same as AB95) |
Mid-Continent Deep Soil (new) |
| 4 | Mid-America Deep Soil AB95 source (modified) |
AB95 | Mid-America (new) |
Mid-Continent Deep Soil (new) |
| 5 | Mid-America Deep Soil USGS96 source (modified) |
USGS 96 150 bar | Mid-America (new) |
Mid-Continent Deep Soil (new) |
Since we are tasked with updating the 1996 NEHRP probabilistic seismic hazard maps for Mid-America, all deviations from the USGS procedure must be justified and documented. There must a transition between current maps and the modified area. Thus the USGS 1996 ground motion model is included as Model 2.
The USGS 1996 model differs significantly from the Atkinson and Boore (1995) model in the source spectrum. The USGS models uses a 150 bar Brune spectral scaling, while the AB95 model uses an empirical scaling which differs from the USGS model for large moment magnitude earthquakes. Thus the AB95 model is offered as an alternative.
The deep soils in mid-America are not included in either the AB95 or USGS96 grounnd motion scaling. The prototype Mid-Continent Deep Soil model gives site amplification and kappa values that differ according to the thickness of the soils. Model 3 differs from the USGS96 model only in the amplification and kappa values. In effect this is done by stripping off the B-C boundary surface, and grafting the deep soil model onto it.
Recent, unpublished studies by Herrmann and others provides more information on crustal wave propagation in Mid-America centered on New Madrid ( Ground Motion Scaling from Earthquakes in the New Madrid Seismic Zone). Crustal wave propagation differs from that used in AB95 and USGS96 in both the Q(f) quality factor and g(r) geometrical spreading terms. In addition a constraint on the composite effects of site amplification and kappa is found for the region between New Madrid, MO, and Dyersburg, TN. However, no new source scaling information is available, so that either the AB95 source (Model 4) or the USGS96 source (Model 5) scaling is used.
The prototype Mid-America Deep Soil Model consists of an optional soil, over 500 meters of Pennsylvanian/Mississippian limestones, over 500 meters of Cambrian/Ordovician limestones etc, over a preCambrian basement.
The deep soil model is constrained by shallow shear-wave velocity measurements made by Paul Mayne and others in the Bootheel, Memphis and western Kentucky. The proposed shear wave velocity model has velocities, Q and density which increase with depth. A single power law relation is used. The power law for velocity is constrained by the surface shear-wave velocity measurements and the requirement that the vertical travel time from the rock/soil contact at New Madrid by 0.6 seconds. The Qs is not as well constrained, other than having some reasonable value near the surface at New Madrid, and a kappa of 0.048 through 600 m of sediments. The power law relation requires more study since the exponent permits extrapolation from New Madrid observations to the 1000 m thick Memphis site (the vertical shear-wave travel time may be appropriate).
For the Paleozoic layers, we use determinations of surface rock shear-wave
velocities by Dr. Ron L. Street of the University of Kentucky
mailto:GEO151@UKCC.UKY.EDU
Date: Sat, 13 Mar 99 08:03:30 EST
From:
These values are simlar to results from surface wave dispersion studies
in the area by Woods et al (1989) and Hutchensen (1994)
| Layer | Material | Thickness | P-vel (m/s) | S-vel (m/s) | Density (gm/cc) | Qp | Qs |
| 1 | Soil | h = 0-2000 m | 1800 | 250 h0.18 | 0.8 log10 Vs - 0.1 | 6 h0.24 | 6 h0.24 |
| 2 | Upper Paleozoic | 500 m | 4500 | 2500 | 2.5 | 500 | 500 |
| 3 | Lower Paleozoic | 500 m | 5000 | 3000 | 2.6 | 500 | 500 |
| 4 | PreCambrian | - | 6000 | 3500 | 2.7 | 500 | 500 |
The present model of the deep soil should not change drastically as they evolve. The variation of parameters with depth into deep soils will be refined as new research is incorporated.
Walt Silva (personal communication) cautioned that modifications to the point source model used in the current simulations may be required close a large earthquake. In addition some of the sharp changes in the geometrical spreading terms seen in studies of small earthquakes will be smoothed. The net effect is that current simulations of large New Madrid earthquakes may overestimate ground motions at short distances.
The current choice of models does not use the latest EPRI model for central and eastern U. S. Since that model is the result of significant research, it should also be included as an option.
Investigate ground motions near a finite fault
Acquire more data on shallow shear-wave velocities and attempt to get Qs information.
Atkinson, G. M., and D. B. Boore (1995). Ground-motion relations for eastern North America, Bull. Seism. Soc. Am. 85 17-30.
Boore, D. B. (1996). SMSIM - Fortran Program for Simulating Ground motions from Earthquakes: Version 1.0, USGS Open File Report 96-80-A
Frankel, A., C. Mueller, T. Barnhard, D. Perkins, E. V. Leyendecker, N. Dickman, S. Hanson and M. Hopper (1996). National Seismic-Hazard Maps: Documentation June 1996, USGS Open-File Report 96-532
Hutchensen, K. D. (1994). Shallow structure of the Illinois Basin from fundamental and higher-mode regional surface wave dispersion, Ph. D. Dissertation , Saint Louis University, 243pp.
Schneider, J. A., and P. W. Mayne (1998). Results of seismic piezocone and flat plate dilatometer tests performed in Blytheville, AR, Steele, Mo, and Shelby county, TN. Interim Report MAEC Project No. GT-3, GTRC Project No. E20-677, Geosystems Engineering Group, Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0355.
Woods, M. T., D. R. Russell, and R. B. Herrmann (1989). Dispersion of short period Rayleight waves with the Ozard Uplift and Illinois Basin, Seism. Res. Let. 60, No. 3., 111-118.
Bob Bauer (Email: bauer@isgs.uiuc.edu) (personal communication), Illinois Geological Survey, gave me the following tabulations. For more details, get in touch with him. These are average values compiled from various sources which used different shearwave determination methods. As new sites/values are aquired average values may change. Question marks are where a lack of data exists and values are best estimates.
| ID | Material | Vs (m/sec) |
| A | Cahokia Alluvium | <230 |
| D | Parkland Sand - dunes | <330 calf |
| E | Carmi Member of Equality | <170 |
| P | Peoria Loess and Roxanna Silt | <200? |
| G | Glasford Till | <365 |
| O | Sand and Gravel of Glasford | <200? |
| M | Mounds Gravel | <360 |
| T | Tertiary clay and sand | <324 |
| K | Cretaceous sand and gravel | <280 |
| C | Cherty residuum | <200? |
| S | Sandy residuum | <200? |
| R | Sandy cherty residuum | <200? |
| Z | Tertiary, Cretaceous or Miss. | 2000 |
| 1 | Penn. shale | 1500 |
| 2 | Penn. sandstone | 2000 |
| 3 | Miss. shale | 2000 |
| 4 | Miss. limestone | 2900 |
| 5 | Devonian limestone | 2900 |
| 6 | Silurian limestone | 2700 |
| 7 | Devonian/Silurian dolomite/limestone | 2900 |
| 8 | Ordovician shale | 2000 |
| 9 | Ordovician sandstone,dolonmite | 2000 |
| 10 | Ordovician dolomite | 2900 |
| 11 | Ordovician sandstone | 2000 |
| 12 | Ordovician limestone/dolomite | 2900 |
rbhsm18.exe self-extracting zip archive
Create a new directory in and MS-DOS window. Go to that directory. Copy rbhsm18.exe to that directory, and execute the program. You will find dorvt180.f, dorvt180.exe, rv_drvr.exe and td_drvr.exe.
The Herrmann executables were compiled using g77 MINGW32 Distribution of G77, GCC, G++ For related pages see GNU Win32 related projects, and EGCS Development Toolchain for x86-win32 targets These compilers are free and work under W95/98/NT. It is only necessary to find a suitable version of make
Purpose and use of the program dorvt180. The purpose of dorvt18X is to create the data files for working with Boore's SMSIM18 package. The 'X', now currently '0' permits us to change the ground motion models, but still maintain compatibility with the SMSIM18 formats.
On Windows 95/98/NT go to an MS-DOS window. Then CD to the directory
for working with these programs, perhaps
cd c:\usr\boore.99
You may wish to place your executables into c:\usr\boore.99\bin
Go to a work directory for this simulation, e.g., something like
cd work
Now run the program dorvt180 to compute the data files
(assuming that its relative location in a neighboring bin18
directory):
..\bin18\dorvt180
You will see the following:
DORVT
This program creates control files for use with Dr.
David Boore s programs (SMSIM1.8) for simulating earthquake
ground motions. The choices permit only certain Eastern
North America ground motion models
(SMSIM - Fortran Program for Simulating Ground motions from
Earthquakes: Version 1.0, USGS Open File Report 96-80-A)
Enter Ground Motion model:
1 Atkinson-Boore 1995 ENA
2 Frankel NEHRP 1996 ENA
3 Frankel (modified) Deep Soil
4 Mid-America Deep Soil - AB src
5 Mid-America Deep Soil - F src
1
Enter deep soil thickness meters
(0-2000) meters
Ignored for models 1 and 2
0
Enter moment magnitude (3.0-8.5):
6
Enter Hypocentral Distance km(1.0-1000):
10
Enter oscillator damping (0.0-1.0):
0.05
Enter Nper, Tlow, Thigh :
Nper - number of oscillator periods
0 - do not use oscillator
Tlow - lowest oscillator period > 0
Thigh - highest period > 0
20 .1 10
Enter number of runs (1-200):
number of time domain simulations
to be run for average spectra.
For a time history output, enter 1
100
Enter the random number seed (1-32000):
123
If you execute the command DIR, then you will see the following
files in the work directory
rv.dat
td.dat
model.dat
To perform a time domain simulation, just run
The Boore time domain simulation is run, creating the following files
The file tavd.out is the time series outout, and will be very large.
For this example it is 16385 lines long. The first few lines are
The file tddva.out has (period,amplitude) pairs for plotting
the linear asymptotic segments for peak velocity, displacment and acceleration
on tripartite plots.
The file tdcol.out summaries the simulation results, by giving the
filter period, natural frequency, the SD, PSV, and PSA of the simulations and
the ratio (STD/PSV), which is an indication of the variability of
any one simulation. The tdcol.out file so created is
The tdsum.out lists all input parameters from the model.dat
file, and also the mean peak motions from the simulations. An extract of
the output is
Boore provides all sources, except for Numerical Recipes routines.
His executables are compiled with Lahey Fortran and use the PharLap
DOS extender. These work under W95/98/NT.
..\bin18\td_drvr < td.dat > td.out
tdsum.out
tdcol.out
tddva.out
tavd.out
T A V D
0.000000 5.9605E-06 0.0000E+00 0.0000E+00
0.005000 -4.4703E-06 3.7253E-09 3.1044E-11
0.010000 3.6318E-06 1.6289E-09 2.7550E-11
0.015000 -1.0626E-05 -1.5857E-08 2.1684E-11
0.020000 -6.1726E-06 -5.7854E-08 -1.7187E-10
0.025000 -5.9848E-06 -8.8247E-08 -5.3752E-10
0.030000 4.8251E-06 -9.1147E-08 -1.0085E-09
0.035000 -1.6128E-05 -1.1940E-07 -1.4912E-09
0.040000 5.0532E-06 -1.4709E-07 -2.2016E-09
where T is the time in seconds, A, the acceleration in (cm/s/s), V, the velocity
in (cm/s) and D the displacement in (cm) for this simulation.
These computations take some time since 100 simulations were requested
in the dorvt180 responses. In any event, only the time series
from the first simulation is output.
If the long time series is inconvenient, the user can change the sampling interval
from 0.005 to 0.01 seconds to reduce the number of points.
The long time series result from the desire to generate synthetics
that also have realistic displacements.
per freq sd:tdcol___ psv:tdcol___ psa:tdcol___ std/psv:tdcol___
0.100 10.000 2.644E-01 1.661E+01 1.044E+03 1.904E-01
0.127 7.848 3.680E-01 1.814E+01 8.947E+02 2.088E-01
0.162 6.158 4.603E-01 1.781E+01 6.892E+02 2.469E-01
0.207 4.833 6.084E-01 1.848E+01 5.610E+02 2.254E-01
0.264 3.793 7.244E-01 1.726E+01 4.114E+02 2.487E-01
0.336 2.976 9.119E-01 1.705E+01 3.189E+02 2.603E-01
0.428 2.336 1.059E+00 1.554E+01 2.281E+02 2.908E-01
0.546 1.833 1.248E+00 1.437E+01 1.656E+02 3.218E-01
0.695 1.438 1.301E+00 1.176E+01 1.063E+02 3.162E-01
0.886 1.129 1.396E+00 9.899E+00 7.021E+01 3.361E-01
1.129 0.886 1.469E+00 8.175E+00 4.550E+01 3.227E-01
1.438 0.695 1.561E+00 6.818E+00 2.978E+01 3.488E-01
1.833 0.546 1.609E+00 5.516E+00 1.891E+01 3.590E-01
2.336 0.428 1.696E+00 4.562E+00 1.227E+01 3.542E-01
2.976 0.336 1.776E+00 3.749E+00 7.914E+00 3.626E-01
3.793 0.264 1.926E+00 3.191E+00 5.287E+00 3.896E-01
4.833 0.207 2.012E+00 2.616E+00 3.401E+00 4.155E-01
6.158 0.162 2.036E+00 2.077E+00 2.119E+00 4.122E-01
7.848 0.127 1.979E+00 1.584E+00 1.268E+00 4.090E-01
10.000 0.100 1.883E+00 1.183E+00 7.432E-01 3.859E-01
r, amag, kappa = 1.000E+01 6.000E+00 0.000E+00
Time Start: 12:30:20.00
Column file: tdcol.out
const= 4.028E-24
amag, stress, fa, fb, durex= 6.000 0.00E+00 1.629E-01 2.004E+00 3.07E+00
am0, am0b_m0fa= 1.122E+25 4.989E-02
npts, dt, total duration = 16384 0.00500 81.9
pgd(cm) std/pgd pgv(cm/s) std/pgv pga(cm/s2) std/pga
1.64E+00 3.70E-01 1.07E+01 1.74E-01 7.14E+02 1.20E-01
Arias intensity(cm/s) std/Arias
1.70E+02 5.65E-02
Fractional oscillator damping = 0.050
per(s) freq psv(cm/s) std/psv psa(cm/s2) psd(cm)
0.100 10.000 1.66E+01 1.90E-01 1.04E+03 2.644E-01
0.127 7.848 1.81E+01 2.09E-01 8.95E+02 3.680E-01
0.162 6.158 1.78E+01 2.47E-01 6.89E+02 4.603E-01
David Boore's Distribution:
USGS ftp site
READ.ME for Version 18
SMSIM Version 1.84 self-extracting zip archive
Local SLU mirror for this software
READ.ME for Version 1.81
SMSIM Version 1.81 self-extracting zip archive