U.S. GEOLOGICAL SURVEY DIGITAL DATA SERIES DDS-7
Digitized Strong-Motion Accelerograms
from North & Central American
through 1986
by
Linda C. Seekins
A. Gerald Brady
Catherine Carpenter
Nicholas Brown
TECHNICAL INFORMATION
INTRODUCTION
Many agencies are currently collecting and distributing digital
strong-motion accelerograms in North America, and many have done so
in the past. With their help, we have amassed a data base of 1,477
mostly three-component station recordings from about 500
earthquakes. These data represent all of the available North
American and Hawaiian records written by ground-level instruments.
They have all been copied into a uniform file format, with one file
for each component of the recording station: each file includes
information about the earthquake and recording station. The
complete set of data files is available on a CD-ROM optical disk.
A BRIEF HISTORY OF ACCELEROGRAM CATALOGS
The set of reports containing accelerogram listings and processing
plots informally called the Blue Book series, published by the
California Institute of Technology (Caltech) from 1969 to 1974, was
the first major effort to catalog and distribute digital
strong-motion-acceleration records. It contained most of the
United States records from 1933 through the San Fernando earthquake
of February 9, 1971. After its publication, many more digitized
analog film records have been compiled, and digital strong-motion
recordings as well as the agencies that collect them have
proliferated, partly because the interest in strong-motion data has
increased and partly because the collection of digital accelerograms
is easier now.
Modern digital recording systems do not require
the expensive and time-consuming step of digitizing
film or paper records. All accelerograms recorded on these
instruments are preserved (at least initially) in digital form,
even those that might have been considered too uninteresting or
insignificant to digitize had they been recorded on film.
1
The result is that more agencies with more instruments are
producing more strong-motion records. The National Geophysical
Data Center (NGDC) distributes the accelerograms provided to it
by several agencies, as does the Lamont-Doherty Geological
Observatory of Columbia University under the aegis of the
National Center for Earthquake Engineering Research (NCEER).
THE NEED FOR A NEW CATALOG
After the publication of the Caltech's Blue Book series, other
catalogs that contained many important acceleration records have
been compiled, but none so comprehensive. Our catalog represents
an effort to collect and archive together all of the ground-level
digital strong-motion accelerograms that have been written at
permanent recording stations in North America through the end of
1986. Furthermore, all of these records are now available on one
CD-ROM optical disk.
In addition to consolidating the records of several agencies, we
discovered problems that the publication of this collection should
solve. With the passing of time and changes in personnel, some
records were misplaced; we are aware of about a dozen that we were
unable to find. Another problem, more easily solved, was caused by
the rapid obsolescence of computer systems. We encountered major
difficulties in trying to read some of the tapes that had been
written by now-antiquated computers. In addition, some older tapes
were beginning to show signs of deterioration. Some of the records
had not been used for such a long time that they were still stored
on cards, making them unreadable at the institute that loaned them
to us, because it no longer has a card reader.
THE RECORDS
This collection contains all of the digital strong motion
accelerograms that we were able to locate which were written before
1987 at permanent ground-level recording stations located in North
America or Hawaii. We also included records from temporary
stations that were written by earthquakes of magnitude greater than
or equal to 5, or that were located in the data-poor central or
eastern regions of the continent, where data are more sparse than
in the west. Two exceptions to this are the Oroville, Calif.
aftershock sequence of 1975, which would have been excluded had the
criteria been strictly applied, and the Enola, Ark. swarm of 1982,
part of which was omitted. The Oroville sequence is included
because it covers a wide range of magnitudes at small distances.
For the Enola swarm, we excluded records from earthquakes of
magnitude less than 2.5 because of the large number of recordings.
2
We emphasize that this collection is a ground-level data set. Many
of these accelerograms were written on instruments described as
"free field". (We use this term here, although a true free-field
station is impossible.) Many other records were written on
instruments located in basements or on the ground floors of
buildings which are so large that they should not be considered
free-field recordings. The user who must avoid recordings
that contain structural noise should be wary of these records. In
recent years, many accelerograms have been written at large,
extensively instrumented structures. Where these instrument
packages include free-field sensors, only those records are
included. If there is no free- field sensor, the building
ground-level or basement instrument recordings are included.
Most of the accelerograms were digitized from film or paper
records. They came to us in the form of unequally spaced (time,
acceleration) pairs, which were linearly interpolated to even time
spacing (200 points per second) by using the HIFRIC program of the
AGRAM package (Converse, 1984) with the interpolate-only option.
We chose this format in the interest of conserving space. In spite
of the large storage capacities of CD-ROM's, we needed to minimize
the individual file size because of the large number of
acceleration records. By using evenly spaced values, we were able
to save the space that would have been occupied by the time values.
More recently,many of the records were digitally recorded at evenly
spaced intervals, some at 100 points per second. In the interest
of consistency, these were interpolated to 200 points per second.
A few records from the 1962 Acapulco earthquake that we received
through Caltech were in the form of evenly spaced data at 10 points
per second; we left these records as they were.
Each file consists of 80-byte ASCII card-image records.
NOTES CONCERNING UNCORRECTED DATA, 1975-79
Since 1975, the U.S. Geological Survey (USGS) has used a commercial
digitizing company to digitize film records: LS Associates, located
in Santa Clara, Calif. (formerly IOM/Towill). For records processed
between 1975 and 1979, a point-removal algorithm was used to
shorten the arrays of uncorrected data originally digitized at
approximately 600 samples per second, and denser near sharp peaks.
The algorithm removed a point if it lay sufficiently close to a
straight line between its two surrounding points. The process was
repeated for newly adjacent points, so that sections of trace
appearing to be straight might actually be defined by only the two
end points. Subsequent interpolation at 200 samples per second for
this collection has resulted in two obvious features:
1. The straight-line segments mentioned above will be refilled
with interpolated points, giving a false implication that these
segments were initially truly straight.
2.
Sharp local peaks will generally be missed by the 0.005-second
step length and will therefore be reduced.
3
We assume that all points removed by this algorithm did not
contribute to the digitized version of the record, but the process
could have left in place points that were affected by
high-frequency noise, thus giving this noise effectively more
predominance and affecting the high-frequency spectral content.
Because we are dealing with amplitude differences of about 25
microns (25x10E-6 m) on the original film, the total effect is
assumed to be negligible.
HOW TO CORRECT THE RECORDS
The files consist of evenly spaced uncorrected accelerograms,
corresponding to Volume 1 of Caltech's Blue Book series. We chose
to publish uncorrected records despite the greater interest of the
engineering community in corrected data, because the CD-ROM disk is
primarily an archive. As discussed earlier, we are storing digital
accelerograms in this collection partly to prevent their permanent
loss, as well as to facilitate their distribution. The uncorrected
records stored here can be corrected by using values that suit each
user. Correction procedures basically include bandpass filtering
(removing noise contamination) and instrument correction (removing
the effects of frequency-dependent instrument response).
By
publishing the accelerograms in a more pristine condition, we may
be inconveniencing some users. However, a user requiring, for
whatever reason, a wider band, would not be able to recover the
data from a corrected version. If there is sufficient demand, a
collection of corrected accelerograms may be published in the
future.
Software that will process these records on a personal computer
(PC) is available from the USGS. The software, currently named BAP
(for Basic Accelerogram Processing), will apply linear corrections
(subtraction of a best-fit straight line), if necessary, instrument
corrections, and filters. It will integrate an acceleration-time
series to velocity and displacement, compute Fourier amplitude
spectra and response spectra, and plot the results at each step.
For information on acquiring the most recent version of the
software, send a self-addressed stamped envelope to:
Attn: April Converse
U.S. Geological Survey, M/S 977
ES&G Data Project (BAP)
345 Middlefield Road
Menlo Park, CA 94025-3591 U.S.A.
For the user who wishes to correct these records (using BAP or
other software), the procedure is discussed in the BAP user's
manual (Converse, 1991). In addition, many of the references
mentioned in the individual files discuss corrected records and
list the filter values used to produce them. The California Strong
Motion Instrumentation Program (CSMIP) of the California Department
of Conservation's Division of Mines and Geology (CDMG) have asked
that their recommended filters for correcting their records be
listed in the file headers, (see below). In addition, the comment
section of each file contains the following statement:
4
********************
This is an uncorrected (Volume 1) accelerogram provided by the
California Strong Motion Instrumentation Program (CSMIP) of the
California Department of Conservation's Division of Mines and
Geology. The corrected (Volume 2) accelerogram is available from
that agency. However, if the user prefers to apply their own
correction procedures, CSMIP recommends, based on digitizing noise
analysis, that among other data correction aspects, a bandpass
filter with ramps at:
" f1 ", " f2 ", " f3 ", " f4 "
cycles/sec be used. To help establish the benefit of data
collected at State of California expense, please send a reprint of
any publication using this accelerogram to:
California Department of Conservation
Division of Mines and Geology
630 Bercut Drive
Sacramento, California 95814
Attn: Data Utilization
**************************
We urge the reader to follow the CDMG's wishes.
A NOTE ON "COMPONENT DIRECTIONS" ON USGS ANALOG FILM RECORDS
In 1978, two changes were made to the way "component directions"
were listed in USGS, and earlier, reports containing information on
original strong-motion records. Before the Santa Barbara
earthquake of August 13, 1978, the component direction was listed
as "pendulum motion," that is, the direction in which the
transducer mass and its mirror were displaced by the technician to
make the trace to move in the positive direction (upward on the
film). Previously, the direction was written in quadrant form, for
the direction of "ground" or "instrument" or "case" acceleration
the causes a positive trace direction on the film. This direction
is 180 degrees different from that in the previous convention. At
the same time, the method of direction notation was changed to
azimuthal (degrees clockwise from North). Our previous example of
S50W would be rotated 180 degrees to N50E and would be written as
50 degrees.
Caltech made an independent effort during 1968 to 1975 to
standardize component directions in its reports (the Caltech
reports listed directions in both quadrant and azimuthal format).
The choice of component direction is the same as the USGS post-1978
convention: "ground" or "case." Many errors have since been found
or suspected, particularly in those accelerograms recorded from
1933 through 1968. The user is cautioned when using these records
if he or she needs specific positive or negative directions for his
or her investigations.
5
THE HEADER INFORMATION
Each file contains a header section before the set of evenly
spaced acceleration values. The header is designed to provide the
user with information about the earthquake and the recording
instrument (see appendix B for a more complete description of the
file format). It includes a few lines of prose designed to
identify quickly the earthquake and recording station, followed by
48 integer variables and 50 real variables. Both the integer and
real headers contain several slots as yet undefined; these slots
were included so that more information can be added to future
records without changing the format. In addition to the headers,
is a variable number of comment lines (the number of comments is
indicated as the 16th integer value) that can contain additional
information about the earthquake or the record. For example, in
the case of the CSMIP records, they contain the correction
parameters described above. The 18th integer value is a mistake
flag. Most of the time it is set to zero, but if there is a
problem with the record, such as spikes or unusual noise, it is set
to 1, in which case, additional information will be found in the
comment section of the file header. We recommend that programs
written to use these files should identify records with I18 = 1 and
bring them to the user's attention.
The comments usually list one or more references that describe the
earthquake, station, or some other aspect of the record. The
earthquake locations and magnitudes were taken from these
references. It is not uncommon for more than one agency to collect
digitized accelerograms and provide references. This overlap can
result, for example, in the header information for different agency
recordings of the same earthquake containing different source
locations or magnitudes.
In the same vein, for some accelerograms written on temporary
instruments at Mammoth, Calif., the magnitude listed is less than 5.
According to our criteria, these accelerograms should not have been
included, but if any agency recording an earthquake determined
its magnitude as 5 or larger, we included all of the accelerograms
it wrote from all agency networks. Another type of possibly
mismatched information occurs in the headers of the
Universidad Nacional Autonoma de Mexico (UNAM) accelerograms:
The earthquake locations are from the USGS' Earthquake Data Base
System, but the distances are from the headers of the original
UNAM files. Differences might exist between these distances
and any that the user might calculate using the earthquake
and station locations contained in the headers.
We did not have the time and resources to do a thorough literature
search for every piece of information in each of the station
recordings. In some cases, the reference cited was preliminary and
may be superseded by later work. The information contained in the
headers is useful as a guideline and commonly is the best
available, but we recommend that those who want a high degree of
accuracy in the epicentral distance, epicenter location, and (or)
earthquake magnitude check that the reference(s) listed meet their
specifications.
6
PECULIARITIES IN THE DATA FILES
As might be expected in any collection this large, there are a few
quirks in the data. We suggest that the user be aware of the
following:
Caltech's Blue Book series files list time in Pacific standard or
daylight time (P.s.t. or P.d.t.)(the rest of the records are in
universal time coordinated [U.t.c.]). We left these as they were,
but wrote "PST" next to the time. Also in the Blue Book series
records, we substituted the magnitudes and distances from Joyner
and Boore (1981) wherever possible.
The CDMG's Mammoth Lakes instrument parameters (frequency and
damping) were contained in the original computer file headers and
do not always agree with the reference cited.
The null (no entry) value is usually -32768 for integers and
3.0E-38 for real numbers. Occasionally, the reformatting program
picked up other values contained in the input files. Therefore, we
recommend that programs read the null value from each file instead
of assuming the values listed above. A similar warning is
necessary for the sampling rate: Most of the records have a
sampling rate of 200 points per second, but, as mentioned earlier,
the 1962 records from Acapulco were provided to us through Caltech
with a sampling rate of 10 points per second. We recommend that
any software used with these records read the sampling rate instead
of assuming that it will be 200 points per second.
Some records list the horizontal orientation for vertical records
as 0 instead of the null value. This is because it was listed that
way in the original record.
The value of ML listed in the digital Guerrero array (University of
Nevada at Reno, [UNR]/UNAM) is really M-II, the magnitude given in
the SISMEX bulletin, based on coda duration.
The number of points in some records is greater than 32678, a value
that can cause problems in user programs if it exceeds the maximum
value that can be used as an integer.
FILE NAMES
We wished the file names to describe the contents. Because we are
limited to 12 characters (at least on PC's), we came up with the
following somewhat-unwieldy convention. The files from each year
are stored in a separate directory (named by year). Characters 1-3
are the day of the year (001-366); character 4 is a letter
corresponding to the hour (A=0,...X=23); characters 5-6 are the
minutes; characters 7-11, are the four-character station name,
unfortunately split by a period in character 9; and character 12 is
the component code. For example, a recording of the third
component of station STNA from an earthquake occurring on July 20
(J.d. 201), 1979 at 10:22 U.t.c. would be in the directory 1979 in
a file called 201K22ST.NAC.
7
THE STATION CODES
The four-character station codes were taken, wherever possible,
from Switzer and others (1981) or from the agency which provided
the records. Generally they are only three characters long, in
which case the fourth character is a zero. When two earthquakes
occurred within the same minute, we used 1 as the fourth character.
For some records, no station code was listed in the literature; in
this case, we made up a four character code with X as the first
character, although not all station codes beginning with X are our
invention.
THE DATA-BASE INDEX FILES
We have included a set of five files containing a brief description
of each accelerogram. These files were designed to be used as
input to a data base, so that the user can select records of
interest. For each accelerogram they include the earthquake name,
station name, component, date, time, maximum and minimum
acceleration, earthquake location and magnitude, station location
and epicentral distance. This information was taken from the
headers of the data files and is subject to the same warnings about
accuracy. The format of these files is listed in appendix C.
PRIMARY SOURCES OF DATA
Most of the early data (1933-71) were published in the Blue Book
Series (California Institute of Technology 1969-74). These
accelerograms were collected by the predecessors of the USGS'
National Cooperative Strong-Motion Instrument Network, and processed
by the Caltech's Earthquake Engineering Research Laboratory.
Caltech also provided several records obtained after
the Blue Book series was published (the 1971 San Fernando
earthquake was the last earthquake it contained) and a few that
were omitted. The UNAM's Instituto de Ingenieria provided us with
their sizable (>400 station recordings) collection of digital
records from various locations in Mexico (Anderson and Mena, 1987).
John Anderson of the Seismology Laboratory, Mackay School of Mines,
UNR, gave us copies of the records collected from the Guerrero
digital array in Mexico, which UNAM/University of California, San
Diego (UCSD), and UNAM/UNR have been operating since 1985 (Anderson
and others, 1987a, 1987b). After the 1971 San Fernando earthquake,
records from the national network operated by the USGS have been
processed by the USGS, described in a series of USGS Open-File
Reports, and disseminated by the National Geophysical Data Center,
National Oceanic and Atmospheric Administration (NOAA), in Boulder,
Colo. The California Strong Motion Instrumentation Program
provided us with accelerograms from their California array and from
the 1986 San Salvador earthquake. Lamont-Doherty Geological
Observatory of Columbia University also maintains the NCEER's
Strong-Motion Data Base (Friberg and Jacob, 1990). The U.S. Army
Corps of Engineers has collected records from dams in New Hampshire
and Idaho (Chang, 1985, 1987). Robert Herrmann of Saint Louis
University (SLU) provided accelerograms from the New Madrid, Mo.,
area.
8
Canadian records are from the Geological Survey of Canada
(Weichert and others, 1982, 1986). Southern California Edison sent
us several records from their instruments at several sites in
southern California and the Sierra Nevada. Kinemetrics, Inc.,
furnished us with accelerograms from the 1984 Morgan Hill, Calif.,
earthquake written at facilities owned by IBM Corp. and maintained
by Kinemetrics. The record from the 1986 Painesville, Ohio, main
shock was written at the Perry Nuclear Power Plant, owned by the
Cleveland Electric Co.
Much of our information about earthquakes and accelerograms came
from previous catalogs, as described in detail by Seekins and
others (1989).
ACKNOWLEDGMENTS
This collection would not exist without the help of the following
individuals. Tom Hanks has always been the driving force behind
this project. Inspired by the storage capability of CD-ROMs, it
was his idea to assemble and distribute this data set on what was,
at the time, a relatively new medium. April Converse wrote the BAP
software that is available to process the data in this collection;
she also wrote the AGRAM software that we used to process most of
the files. She has often helped us with her programming knowledge
and advice; we appreciate her attention to potential problems in
the data set and, most importantly, her good spirit, patience, and
constant encouragement. Larry Baker was invaluable in helping us
to read magnetic tapes from antiquated computers. His
understanding of computer systems was a valuable resource
throughout the lifetime of this project; he has always been
generous with his time and ideas. Howard Bundock also came to our
assistance several times during computer crises. Chuck Mueller
supervised the project and provided thoughtful guidance.
Bill Joyner had already accumulated a large data subset on magnetic
tape and was helpful in finding several records; he also provided
information and ideas that were helpful in shaping the catalog as
a whole. Pete Mork patiently searched old tapes written by former
employees to find obscure records for us. Jo Switzer maintains an
excellent data base of information about the recording stations; it
was an important resource. Dave Boore helped us check the accuracy
of the index files. Tom Holzer facilitated data collection
and publication. Carl Abston of the USGS Office of Scientific
Publications in Denver, Colo., helped us with the nuts and bolts of
writing the files onto CD-ROM. In addition to providing us with
data from the Guerrero digital array, John Anderson of UNR's Mackay
School of Mines, acted as an intermediary between the USGS and
UNAM, arranging for the release of their data and transporting
magnetic tapes. He has been supportive of this effort and was
generous with his time and guidance, as well as with his data; we
have benefited greatly from his interest and assistance.
UNAM's
Instituto de Ingenieria went to a great deal of trouble to make
copies of their data for us; we are grateful that they provided us
with their records and gave us permission to publish them.
9
Jim Beck of Caltech helped us to locate post-Blue Book series
records. Ahmed Abdel-Ghaffar of the University of Southern
California
made a valiant, albeit-unsuccessful effort to find the lost records
from the 1976 Whittier, Calif., earthquake. George Segal of
Kinemetrics Inc., and Frank Stead and Mike White of the Cleveland
Electric Co. arranged permission for us to use the Perry Nuclear
Power Plant record written by the January 1986 Cleveland, Ohio
earthquake. Charles Kircher of Jack Benjamin and Associates and
Dale Parker of IBM Corp. arranged permission for us to use IBM's
Morgan Hill records. Paul Friberg helped us to use the NCEER data
base and provided us with Lamont-Doherty-processed Alaska records.
Dennis Ostrom of Southern California Edison sent us copies of their
records and information about them.
REFERENCES
Anderson, J.G., R. Quaas, D. Almora M., J. Manuel Velasco, E.
Guevara O., L.E. de Pavia R., A. Gutierrez R., and R. Vazquez L.,
1987a, Guerrero, Mexico Accelerograph Array: Summary of Data
Collected in the Year 1985: Guerrero Array Team, Instituto de
Ingenieria - UNAM and Seismological Laboratory, UNR Report GAA-2.
Anderson, J.G., R. Quaas, D. Almora M., J. Manuel Velasco, E.
Guevara O., L. E. de Pavia R., A Gutierrez R., R. Vazquez L.,
1987b, Guerrero, Mexico Accelerograph Array: Summary of Data
Collected in the Year 1986: Guerrero Array Team, Instituto de
Ingenieria - UNAM and Seismological Laboratory, UNR Report GAA-3.
California Institute of Technology, 1969-74, Strong Motion
Earthquake Accelerograms - Uncorrected Accelerograms, Earthquake
Engineering Laboratory; Pasadena.
Chang, F.K., 1985, Analysis of Strong-Motion Data From the Mount
Borah, Idaho, Earthquake of 28 October 1983: U.S. Army Corps of
Engineers, Waterways Experiment Station, Miscellaneous Paper
GL-85-12.
Chang, F.K., 1987, Response Spectral Analysis of Franklin Falls
Dam, New Hampshire: U.S. Army Corps of Engineers Miscellaneous
Paper GL-87-1.
Converse, April, 1984, AGRAM: A Series of Computer Programs for
Processing Digitized Strong-Motion Accelerograms, Version 2.0:
U.S. Geological Survey Open-File Report 84-525.
Converse, April, 1991, BAP: Basic Strong-Motion Accelerogram
Processing Software, Version 1; in press.
Friberg, P.A. and K.H. Jacob, 1990, NCEER Strong-Motion Data Base:
A User Manual for the GeoBase Release (Version 1.0 for the SUN3).
NCEER Technical Report NCEER-90-0005.
10
Joyner, William B., and David M. Boore, 1981, Peak Horizontal
Acceleration and Velocity from Strong-Motion Records Including
Records from the 1979 Imperial Valley, California Earthquake.
Bull. Seis. Soc. Am., Vol. 71, no.6, p. 2011-2038.
Seekins, Linda C., A. Gerald Brady, and Charles S. Mueller, 1989,
Digitized Strong-Motion Accelerograms of North America Through
1986: U.S. Geological Survey Open-File Report 89-93, 37 p.
Switzer, J., D. Johnson, R. Maley, and R. Matthiesen, 1981, Western
Hemisphere Strong-Motion Accelerograph Station List - 1980; U.S.
Geological Survey Open-File Report 81-664.
Weichert, D.H., P.W. Pomeroy, P.S. Munro, and P.N. Mork, 1982,
Strong Motion Records from Miramichi, New Brunswick, 1982
Aftershocks: Pacific GeoScience Centre, Earth Physics Branch Open
File Report 82-31.
Weichert, D.H., R.J. Wetmiller, R.B. Horner, P.S. Munro, and P.N.
Mork, 1986, Strong Motion Records from the 23 December 1985, Ms 6.9
Nahanni, NWT, and some Associated Earthquakes. Geological Survey
of Canada, Pacific Geoscience Centre, Open File Report 86-1-PGC,
9 p.
APPENDIX A - REFERENCES CITED IN THE DATA FILES
Anderson, John G., and Richard S. Simons, 1982, Mexicali Valley
Accelerogram Data: 1978-1980: Institute of Geophysics and
Planetary Physics, Strong Motion Project Report 82-1, UCSD, 5 p.
Anderson, J.G., R. Quaas, D. Almora M., J. Manuel Velasco, E.
Guevara O., L.E. de Pavia R., A. Gutierrez R., and R. Vazquez L.,
1987, Guerrero, Mexico Accelerograph Array: Summary of Data
Collected in the Year 1985: Guerrero Array Team, Instituto de
Ingenieria - UNAM and Seismological Laboratory, UNR Report GAA-2.
Anderson, J.G., R. Quaas, D. Almora M., J. Manuel Velasco, E.
Guevara O., L.E. de Pavia R., A. Gutierrez R., and R. Vazquez L.,
1987, Guerrero, Mexico Accelerograph Array: Summary of Data
Collected in the Year 1986: Guerrero Array Team, Instituto de
Ingenieria - UNAM and Seismological Laboratory, UNR Report GAA-3.
Anderson, J.G. and J.N. Brune, 1991, The Victoria Accelerogram for
the 1990 Mexicali Valley Earthquake; Earthquake Spectra, in press.
Beaven, J., and K.H. Jacob, 1984, Processed Strong-Motion Data from
Subduction Zones: Alaska; Report 1 in the Series 'Lamont-Processed
Strong Motion Data', Lamont-Doherty Geological Observatory.
Brady, A.G., E.C. Etheridge, R.P. Maley, P.N. Mork, B.L.
Silverstein, D.A. Johnson, A.V. Acosta, R.D. Forshee, and M.J.
Salsman, 1986, Preliminary Report on Records from the
USGS-Maintained Strong-Motion Network in the Hollister Area January
26, 1986.
USGS Open-File Report 86-156.
11
Brady, A.G., and V. Perez, Strong-Motion Earthquake Accelerograms
Digitization and Analysis, USGS Seismic Engineering Data Report,
1972 Records. USGS Open-File Report 78-941, 1978.
Brady, A.G., and V. Perez, 1983, Processed Accelerograms from
Coyote Dam: USGS Open-File Report 83-166, 82 p.
Brady, A.G., and V. Perez, 1979, Strong-Motion Earthquake
Accelerograms Digitization and Analysis, USGS Seismic Engineering
Data Report 1974-1975 Records. USGS Open-File Report 79-929.
Brady, A.G., R.L. Porcella, G.N. Bycroft, E.C. Etheredge, P.N.
Mork, B. Silverstein, and A.F. Shakal, 1987, Processing of
Strong-Motion Recordings from the Main Shock; in The Morgan Hill,
California Earthquake of April 24, 1984. USGS Bulletin 1639, S.N.
Hoose, ed., p. 53-60.
Brady, A.G., R.L. Porcella, G.N. Bycroft, E.C. Etheredge, P.N.
Mork, B. Silverstein, and A.F. Shakal, 1987, Computer plots of
Strong-Motion Results from the Main Shock; in The Morgan Hill,
California Earthquake of April 24, 1984. USGS Bulletin 1639, S.N.
Hoose, ed., p. 139-256.
Brune, J.N., F.L. Vernon III, R.S. Simons, J. Prince, and E. Mena,
1982, Strong-Motion Data Recorded in Mexico During the Main Shock;
in The Imperial Valley, California, Earthquake of October 15, 1979,
USGS Prof Paper 1254, pp 319-350.
California Institute of Technology, 1969-74, "Bluebook" series Volume 1: Strong Motion Earthquake Accelerograms - Uncorrected
Accelerograms, Earthquake Engineering Laboratory, Pasadena.
CDMG, 1978, Compilation of Strong-Motion Records Recovered from the
Santa Barbara Earthquake of 13 August 1978. California Division of
Mines and Geology Preliminary Report 22, 43 p.
CDMG, 1985, Selected Accelerograms from the Redlands, California
Earthquake of October 2, 1985 (Including First Records from a
Base-Isolated Building). CDMG Preliminary Data Report OSMS 85-02,
17 p.
Chang, F.K., 1985, Analysis of Strong-Motion Data From the Mount
Borah, Idaho, Earthquake of 28 October 1983; U.S. Army Corps of
Engineers, Waterways Experiment Station, Miscellaneous Paper
GL-85-12.
Chang, F.K., 1987, Response Spectral Analysis of Franklin Falls
Dam, New Hampshire. U.S. Army Corps of Engineers Miscellaneous
Paper GL-87-1.
Friberg, P.A., and K.H. Jacob, 1989, Processed Strong Ground Motion
Data From Alaska: First Update, Through June 1987. Report 2 in the
Series 'Lamont Processed Strong Motion Data': Columbia University,
Lamont-Doherty Geological Observatory.
12
Haar, L.C., J.B. Fletcher, and C.S. Mueller, 1984, The 1982 Enola,
Arkansas, Swarm and Scaling of Ground Motion in the Eastern United
States. Bull. Seis. Soc. Am., v. 74, no. 6, p. 2463-2482.
Hartzell, S.H., and Brune, J.N., 1979, The Horse Canyon Earthquake
of August 2, 1975 - Two Stage Stress-Release Process in a
Strike-Slip Earthquake. Bull. Seis. Soc. Am., v. 69, p. 1161-1173.
Hermann, R. B., 1977, Analysis of Strong Motion Data from the New
Madrid Seismic Zone: 1975-1976. Saint Louis University Department
of Earth and Atmospheric Sciences Publication 239, 144 p.
Huang, M.J., D.L. Parke, R.W. Sherburne and A.F. Shakal, 1987,
Processed Strong Motion Data from the Palm Springs Earthquake of 8
July 1986: Part 1. Ground-Response Records. California Strong
Motion Instrumentation Program, Report # OSMS 87-01. CDMG.
Jennings, Paul C., 1962, Velocity Spectra of the Mexican
Earthquakes of 11 May and 19 May 1962: California Institute of
Technology, Earthquake Engineering Research Laboratory, 18 p.
Joyner, William B., and David M. Boore, 1981, Peak Horizontal
Acceleration and Velocity from Strong-Motion Records Including
Records from the 1979 Imperial Valley, California Earthquake.
Bull. Seis. Soc. Am., vol. 71, no. 6, p. 2011-2038.
Kinemetrics, 1982, Data Report:
1978.
Santa Barbara Earthquake August 13
Kinemetrics, 1984, Morgan Hill Earthquake, April 24 1984,
Strong-Motion Data from the IBM Digital Accelerograph Network; San
Jose and Almaden Facilities; for IBM Corporation.
Lee, V.W. and M.D. Trifunac, 1987, Strong Earthquake Ground Motion
Data in EQINFOS: Part 1; University of Southern California,
Department of Civil Engineering Report 87-01.
Maley, R.P and E.C. Etheridge, 1981, Strong-Motion Data from the
Westmoreland, California Earthquake of April 26, 1981; USGS
Open-File Report 81-1149.
Maley, R.P., E.C. Etheredge, and A. Acosta, 1986, U.S. Geological
Survey Strong-Motion Records from the Chalfant Valley, California,
Earthquake of July 21, 1986, USGS Open File Report 86-568, 19 p.
Miller, R.K., and S.F. Felszeghy, 1978, Engineering Features of
the Santa Barbara Earthquake of August 13, 1978; Dept of Mechanical
and Environmental Eng., UCSB; UCSB-ME-78-2; published by Earthquake
Engineering Research Institute.
Mork, P.N., and A.G. Brady, 1981, Processed Accelerogram From
Monticello Dam, Jenkinsville, South Carolina, 16 October 1979, 0706
UTC: USGS Open-File Report 81-1214.
13
Mueller, C., P. Spudich, E. Cranswick, and R. Archuleta, 1981,
Preliminary Analysis of Digital Seismograms from the Mammoth Lakes,
California Earthquake Sequence of May-June, 1980. USGS Open-File
Report 81-155.
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1979, Compilation of Strong-Motion Records from the August 6, 1979
Coyote Lake Earthquake: CDMG Preliminary Report 25; USGS Open-File
Report 79-385.
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407-432.
Seale, S.A.
California;
Advances in
Publication
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Processed Data from the Strong-Motion Records of the Morgan Hill
Earthquake of 24 April 1984, Part 1, Ground-Response Records. CDMG
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14
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15
APPENDIX B - DATA-FILE FORMAT
*
*
XXXXA
date
time(GMT)
M=
Ms=
station=
component=
epicentral dist=
instrument type=
earthquake name
Ml=
pk accel=
data source=
*
*
*
(note: XXXXA represents the five-character station-component
code used in the file name)
INTEGER VARIABLES
variable
number
________
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
(8I10)
description
______________________
integer null value
year (4 digits) first sample time
day of year
"
"
"
hour
"
"
"
minute
"
"
"
second
"
"
"
millisecond
"
"
"
recorder serial number
recorder channel number:this file
recorder channel number:total
number of channels recorded for
this station
sensor serial number
vertical orientation (degrees
from up) 0< I13 <180
horizontal orientation (degrees
east of north) 0< I14 < 360
sensor type code
2 Sprengnether SA-3000
3-component fba
30 Kinemetrics FBA-13
3-component fba
31 Kinemetrics FBA-11
1-component fba
101 SMA-1
102 C&GS Standard
AGRAM/ESG
cross-ref
__________
3
10
11
12
13
14
15
20
28(ESG)
29(ESG)
30
40(ESG)
41
42
43(ESG)
103 AR-240
104 RFT-250
16
16
17
18
105 RFT-350
106 MO-2
107 RMT-280
108 SMA-2/3
109 DSA-1/DSA-3
110 DCA-300
111 DCA-333
112 A-700
113 SSA-1
114 CRA-1
115 MO-2
116 FBA-3
117 SMA-2
118 DCA-310
119 FBA-13
number of comment cards following
the header information
number of acceleration values
mistake flag - I18=1 means that there
is some sort of mistake in the file read the comments before using the
record.
Integer parameters 19-29 are for future structural
collections; they are not used in any of the files in the current
collection.
19
20
21
22
Type of structure
1 building
2 bridge
3 dam
4 other
null not a structure
Structure number corresponding
to printed information
Transducer number of recording
system as shown on the drawing
Total number of transducer channels
for this structure
The following integer parameters are for buildings (1 in
integer variable 18):
23
24
25
Number of floors above grade
including the roof
Number of stories below grade
Floor on which this sensor is located
-1 1st subbasement, etc.
0 basement
1 grade level
2+ floor levels above grade
17
The following are for bridges
26
27
Number of spans
Location of transducer
0 free field
1 at the base of a pier or
abutment
2 on an abutment
3 on the deck at the top of
a pier
4 on the deck between piers
or between an abutment and
a pier
The following are for dams:
28
29
30-48
Location of this transducer
0 upstream or downstream free
field
1 at the base of the dam
2 on the crest of the dam
3 on the abutment of the dam
Type of construction
1 Reinforced-concrete gravity
2 Reinforced-concrete arch
3 earth fill
4 other
Undefined
REAL VARIABLES(5E15.7)
variable
number
_________
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
description
_____________
real null value
sample rate (samples/s)
earthquake latitude (dec. deg.)
earthquake longitude (dec. deg.)
earthquake depth (km ref. s.l.)
source magnitude M (moment
magnitude)
"
"
Ms
"
"
ML
"
"
M (other)
seismic moment (dyne-cm)
station latitude (dec. deg.)
station longitude (dec. deg.)
station elevation (m ref. s.l.)
station offset N (m)
station offset E (m)
station offset up (m)
epicentral distance (km)
AGRAM/ESG
cross-ref
____________
2
5
10 (ESG)
12 (ESG)
14
15
16
40 (ESG)
42 (ESG)
44
19
18
epicenter to station azimuth
(degrees east of north)
0.0 < R17 <360.0
18
20
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33-36
37-50
!
digitizing constant (counts/V)
46
for DR100 data, digitization units
(units/cm) for SMA data
antialias-filter corner frequency 47
(hz)
antialias-filter poles (rolloff=
48(ESG)
6dB/octave per pole)
natural frequency of the sensor
49
(hz)
sensor damping coefficient
50
(fraction of critical)
coil constant(V s**2/cm)
51
for DR100 or recorder sensitivity
(cm/g) for SMA data
amplifier gain (dB) for a DR100
52
pre-amp gain (dB) for a DR100
53
high-pass filter - suggested corner
frequency (default = reciprocal of
two times the strong motion duration
low-pass filter - suggested corner
frequency (natural frequency of the
accelerometer)
time of the maximum value (s)
value of the maximum value (cm/s**2)
time of the minimum value (s)
value of the minimum value (cm/s**2)
F1-F4 - recommended filters for correcting CDMG records
undefined
comment cards go here
Acceleration values 8 (pe10.4e1)
APPENDIX C - INDEX-FILE FORMAT
Station and component code, Earthquake name, Station name,
Component (a5,1x,2a30,a10)
Year, Julian Day, Hour, Minute, Maximum Acceleration, Minimum
Acceleration (4i10,2e15.7)
Earthquake Latitude, Earthquake Longitude, Earthquake Depth,
Station Latitude, Station Longitude (5e15.7)
Moment Magnitude, Ms, ML, M(other), Epicentral Distance
(5e15.7)
19