![](media/image1.png){width="5.0in" height="0.75in"}

**MAIN SHOCK AND AFTERSHOCK RECORDS**

**OF THE 1999 IZMIT & DÜZCE, TURKEY EARTHQUAKES**

**USGS/OFDA PROJECT**

**\[USGS PROJECT NO: 1-7460-63170\]**

By

####### M. Çelebi[^1], Scientific Editor

S. Akkar[^2]

U. Gulerce[^3]

A.Sanli^1^

####### H. Bundock^1^

A. Salkin[^4]

Open-File Report 01-163

This report is preliminary and has not been reviewed for conformity with
U.S. Geological Survey editorial standards (or with the North American
Stratigraphic Code). Any use of trade, product or firm names is for
descriptive purposes only and does not imply endorsement by the U. S.
Government

**TABLE OF CONTENTS**

[Acknowledgements of Support 3](#acknowledgements-of-support)

[Acknowledgements of Data Sources & Contributors
3](#acknowledgements-of-data-sources-contributors)

[INTRODUCTION 4](#introduction)

[GENERAL COMMENTS: 6](#general-comments)

[Table 1. Sources of Data 8](#table-1.-sources-of-data)

[Table 2. Summary of stations, components of data and events recorded by
different sources of data (Note: The numbers are approximately correct
and there may be duplicates).
8](#table-2.-summary-of-stations-components-of-data-and-events-recorded-by-different-sources-of-data-note-the-numbers-are-approximately-correct-and-there-may-be-duplicates.)

[ERD-MINISTRY-TURKEY DATA 9](#erd-ministry-turkey-data)

[Acknowledgements: 9](#acknowledgements)

[Data Particulars: 9](#data-particulars)

[ERI-KUDO-JAPAN DATA 9](#eri-kudo-japan-data)

[Acknowledgements: 9](#acknowledgements-1)

[Data Particulars: 9](#data-particulars-1)

[IRIGM-BOUCHON-FRANCE DATA 10](#irigm-bouchon-france-data)

[Acknowledgements: 10](#acknowledgements-2)

[Data Particulars: 10](#data-particulars-2)

[ITU (ISTANBUL TECHNICAL UNIVERSITY) - TURKEY DATA
11](#itu-istanbul-technical-university---turkey-data)

[Acknowledgements: 11](#acknowledgements-3)

[Data Particulars: 11](#data-particulars-3)

[KOERI DATA (KANDILLI OBSERVATORY AND EARTHQUAKE RESEARCH INSTITUTE,
BOSPHORUS UNIVERSITY, ISTANBUL, TURKEY)
11](#koeri-data-kandilli-observatory-and-earthquake-research-institute-bosphorus-university-istanbul-turkey)

[Data Particulars: 11](#data-particulars-4)

[LAMONT-DOHERTY EARTHQUAKE OBSERVATORY \[LDEO\] DATA
12](#lamont-doherty-earthquake-observatory-ldeo-data)

[Acknowledgements: 12](#acknowledgements-4)

[Data Particulars: 12](#data-particulars-5)

[USGS-GOLDEN-USA DATA 13](#usgs-golden-usa-data)

[Acknowledgements: 13](#acknowledgements-5)

[Data Particulars: 13](#data-particulars-6)

[USGS-MENLO-USA DATA 14](#usgs-menlo-usa-data)

[Acknowledgements: 14](#acknowledgements-6)

[Data Particulars: 14](#data-particulars-7)

## Acknowledgements of Support

The financial support of Office Foreign Disaster assistance (OFDA) of
the U.S. Agency for International Development (US-AID), Washington D.C.
is gratefully acknowledged. This effort was conducted under USGS Project
7460-63170.

# 

## Acknowledgements of Data Sources & Contributors

The support and generous input of the following data providers are
specifically acknowledged.

######## 1. ERD-MINISTRY-TURKEY:

**Dr. Murat Nurlu** (Head, ERD, Directorate for Disaster Affairs,
Ministry of Public Works and Resettlement, Ankara, Turkey), and other
ERD staff, Ulubey Çeken, Zahide Çolakoglu, Tulay Ugras, Turgay Kuru,
Mustafa Gurbuz, Aytac Apak, Ugur Kokyer, Celal Cinar, Bekir Tuzel, Murat
Beyhan, Engin Coruh, Engin Inan.

######## 2. ERI-KUDO-JAPAN:

**Professor Kazuyoshi Kudo**,(ERI, Univ. Tokyo, 1-1-1, Yayoi, Bunkyo-ku,
Tokyo 113-0032 Japan, e-mail: <kudo@eri.u-tokyo.ac.jp>, Tel:
+81-3-5841-8251, Fax: +81-3-5841-5809)

######## 3. IRIGM-BOUCHON-FRANCE: 

**Dr. Michel Bouchon** \[Universite Joseph Fourier, IRIGM, BP 53, 38041
Grenoble, FRANCE (33-476-828063, Fax: 33-476-828-101, e-mail:
Michel.Bouchon@ujf-grenoble.fr)\] , Hayrullah Karabulut (Bogazici
University and Kandilli Observatory, Turkey), Marie-Paule Bouin (IPG
Paris, France), Michel Dietrich (University of Grenoble, France), Cecile
Cornou (University of Grenoble, France), Aybige Akinci (Dokuz Eylul
University, Izmir, Turkey) and Mustafa Aktar (Tubitak, and Bogazici
University and Kandilli Obsevatory, 81220 Cengelkoy Istanbul, Turkey)

######## 4. ITU-TURKEY:

**Professor Atilla Ansal**, Civil Engineering Department, Istanbul
Technical University, Maslak, Istanbul, Turkey), Prof.Haluk Eyidogan.
Department of Geophysics, Mining Faculty, Istanbul Technical University,
Maslak, Istanbul, Turkey.

######## 5. KOERI-BU-TURKEY:

All data included in this compilation have been downloaded from :

> <http://www.koeri.boun.edu.tr/earthqk/earthqk.html>.

The data sets included in this compilation are those of the main shocks
for the 17 August 1999 Izmit and 12 November 1999 Duzce events as was
provided on the reference web-site. It is known that, in addition to the
main-shock data, KOERI has collected aftershock recordings following
both earthquakes of 1999. While this CD-ROM was being completed, the
complete data set has been released by KOERI separately during April
2001 (M. Erdik, *pers. comm. 2001*).

######## 6. LAMONT-DOHERTY EARTHQUAKE OBSERVATORY \[LDEO\]-USA:

**Dr. Leonardo Seeber,** (Lamont Doherty Earth Observatory of Columbia
University \[LDEO\], Palisades, NY 10964; <nano@ldeo.columbia.edu>\],
John G. Armbruster, (LDEO), Naside Ozer (The University of Istanbul,
Geophysical Engineering Department, 34850, Avcilar, Istanbul, Turkey),
Mustafa Aktar (Tubitak, and Bogazici University and Kandilli Obsevatory,
81220 Cengelkoy Istanbul, Turkey), Serif Baris (Kandilli Observatory of
Bogazici University, 81220, Cengelkoy, Istanbul), David Okaya
(University of Southern California, Los Angeles, CA 90089),

Yehuda Ben-Zion (University of Southern California, Los Angeles, CA
90089), Ned Field (USGS. Pasadena, Ca. -- formerly, SCEC, University of
Southern California, Los Angeles, CA 90089)

Special acknowledgements are reiterated for the (a) important assistance
of Serif Baris and Mustafa Aktar, both of Kandilli Observatory in
performing this work, and (b) financial support for this work from the
Southern California Earthquake Center \[SCEC\], and the National Science
Foundation.

######## 7. USGS-GOLDEN-USA:

**Dr. Erdal Safak**, (Geologic Hazards Team \[GHT\], USGS, Golden, Co.,
USA, *currently with USGS-Saudi Mission, Jeddah, Saudi Arabia*), Charles
Mueller (GHT), Edward Cranswick (GHT), Mark Meremonte (GHT), Dave Carver
(GHT), Tom Holzer (USGS, Menlo Park, Ca.), Mustafa Erdik (KOERI,
Istanbul, Turkey), Kemal Beyen (KOERI), Oguz Ozel (KOERI) and Muzaffer
Gul (KOERI).

######## 8. USGS-MENLO-USA:

**Dr. Mehmet Çelebi**, Earthquake Hazards Team \[EHZ\], USGS, 345
Middlefield Rd., Menlo Park, Ca. 94025, Christopher Dietel, EHZ, Gary
Glasmoyer, EHZ, Aydin Mert (KOERI-Istanbul)

# INTRODUCTION

The August 17, 1999 Izmit (Turkey) earthquake (M~w~=7.4) will be
remembered as one of the largest earthquakes of recent times that
affected a large urban environment (U.S. Geological Survey, 1999). This
significant event was followed by many significant aftershocks and
another main event (M~w~=7.2) that occurred on November 12, 1999 near
Duzce (Turkey). The shaking that caused the widespread damage and
destruction was recorded by a handful of accelerographs (\~30) in the
earthquake area operated by different networks. The characteristics of
these records show that the recorded peak accelerations, shown in Figure
1, even those from near field stations, are smaller than expected
(Çelebi, 1999, 2000)[^5]. Following this main event, several
organizations from Turkey, Japan, France, and the USA deployed temporary
accelerographs and other aftershock recording hardware. Thus, the number
of recording stations in the earthquake affected area was quadrupled
(\~130). As a result, as seen in Figure 2, smaller magnitude aftershocks
yielded larger peak accelerations, indicating that because of the sparse
networks, recording of larger motions during the main shock of August
17, 1999 were possibly missed.

![](media/image2.jpeg){width="4.118055555555555in"
height="3.046527777777778in"}

Figure 1. Map showing some of the peak accelerations recorded and
plotted at relative locations of significant strong-motion stations
within and in close proximity to the epicentral area (Base map courtesy
of BKS Surveys Ltd., N. Ireland).

![](media/image3.jpeg){width="4.8875in" height="2.026388888888889in"}

Figure 2. Comparison of peak accelerations for the August 17, 1999 main
shock (station SKR) and two aftershocks, each recorded at a different
location (Çelebi, 2000).

It is accepted a priori that each organization had a different objective
in deploying temporary stations. Regardless of the varying objectives,
the recorded main shock and aftershock motions exhibit specific
characteristics of engineering importance and provide opportunities to
further research many aspects of the earthquakes of 1999 for
applications in Turkey and other similar seismic regions of the world.

Several research results have either been published or will be published
in the near future. To help the user of this CD-ROM, we organized a
PUBLICATIONS Directory which includes some of the publications relevant
to the 1999 Turkey earthquakes.

# GENERAL COMMENTS:

1.  The main-shock and aftershock records contained in this CD-ROM
    compilation presented herein have been obtained from eight sources.
    A general description of the sources and the organizations involved
    are summarized in Table 1.

2.  The authors believe that there are additional records that either
    are (a) not widely known to exist or (b) not being released by the
    owners for one reason or another.

3.  The number of permanent and temporary stations that recorded the
    August 17, 1999 Izmit earthquake main-shock and November 12, 1999
    Duzce earthquake main-shock as well as aftershocks and the total
    components of data and number of events are summarized in Table 2.
    The numbers presented in the table are approximate but sufficiently
    accurate.

4.  Each source of data is obtained by different recorders and sensors
    with different binary or ASCII data format (*e.g.* USGS-Menlo data
    is obtained with GEOS recording systems *\[see*
    http://nsmp.wr.usgs.gov/geos/*\].* ).

5.  The variation in instrument types deployed by the different sources
    and the resulting variatiuon in data format led to the decision to
    provide all data in ASCII format so that the user does not have to
    search for or develop converter softwares.

6.  The CD-ROM is organized such that the compiled data and all relevant
    tabulation of station information from each source is in a separate
    directory under the data souce name provided in Table 1. Within each
    data source directory, there are sub-directories. One of the
    subdirectories in each case contains the zipped or unzipped ASCII
    data files.

7.  For each source of data, a specific file describes the station
    identity, coordinates, event time if available, and absolute peak
    value of the specific component of motion.

8.  We have not provided event history. These can be obtained from other
    sources.

9.  Detailed geotechnical description of the stations are not available
    in most cases. However, general descriptions, as provided by the
    sources are provided in the respective directories of each source.

10. No corrections of data are made. Spectral values are not computed or
    provided.

11. A general deployment map identifying the different deployments and
    therefore data contributors identified by a different color-code is
    provided in pdf format. This map is based on the general station
    information table prepared using commercially available
    public-domain software, Excel (ALL_SOURCES_STATIONS_INFO.xls). This
    map can be magnified with the magnifier tool of Adobe Acrobat to get
    a quick understanding of the relative locations of the stations from
    the different sources of data identified by a different color.

12. Similarly, for each data source, one or more detailed maps are
    provided in pdf and other formats.

### Table 1. Sources of Data 

+-----------------------+----------------------------------------------+
| SOURCE OF DATA        | ######### KEY ORGANIZATION                   |
|                       |                                              |
| \[Directory Names in  |                                              |
| for CD-Rom\]          |                                              |
+-----------------------+----------------------------------------------+
| ERD-MINISTRY-TURKEY   | Earthquake Research Institute, Ministry of   |
|                       | Public Works and Reconstruction, Ankara,     |
|                       | TURKEY                                       |
+-----------------------+----------------------------------------------+
| ERI-KUDO-JAPAN        | ERI, Univ. Tokyo                             |
|                       |                                              |
|                       | 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032,     |
|                       | JAPAN                                        |
+-----------------------+----------------------------------------------+
| IRIGM-BOUCHON-FRANCE  | Universite Joseph Fourier, IRIGM, BP 53,     |
|                       | 38041 Grenoble, FRANCE                       |
+-----------------------+----------------------------------------------+
| ####### ITU-TURKEY    | Istanbul Technical University                |
|                       |                                              |
|                       | Maslak, Istanbul, TURKEY                     |
+-----------------------+----------------------------------------------+
| KOERI-BU-TURKEY       | Kandilli Observatory and Earthquake Research |
|                       | Institute, Bosphorus University, Istanbul,   |
|                       | TURKEY                                       |
+-----------------------+----------------------------------------------+
| LDEO-USA              | Lamont Doherty Earth Observatory of Columbia |
|                       | University, Palisades, NY 10964, USA         |
+-----------------------+----------------------------------------------+
| USGS-GOLDEN-USA       | Geological Hazards Team                      |
|                       |                                              |
|                       | United States Geological Survey, Golden,     |
|                       | Colorado, USA                                |
+-----------------------+----------------------------------------------+
| USGS-MENLO-USA        | Earthquake Hazards Team                      |
|                       |                                              |
|                       | United States Geological Survey, Menlo Park, |
|                       | Ca., USA                                     |
+-----------------------+----------------------------------------------+

### Table 2. Summary of stations, components of data and events recorded by different sources of data (Note: The numbers are approximately correct and there may be duplicates).

  --------------------- ------ ------------ ------ -------------- ------- ---------------- ------ ------------
  **SOURCE OF DATA**                               **STATIONS**           **COMPONENTS**          **EVENTS**

  ERD-MINISTRY-TURKEY                              42                     4035                    1345

  ERI-KUDO-JAPAN                                   7                      165                     55

  IRIGM - FRANCE                                   6                      180                     60

  ITU-TURKEY                                       5                      96                      32

  KOERI-BU-TURKEY                                  13                     69                      23

  LDEO-USA                                         24                     33219                   11073

  USGS-GOLDEN-USA              DATA SET 1          16 (\*)                2280                    760

                        DATA                18                    16938                    3267   
                        SET 2               (\*)                                                  

  USGS -- MENLO-USA                                10                     5142                    857

  TOTAL:                                           143                    62124                   17472

  (\*) May be                                                                                     
  duplicates                                                                                      
  --------------------- ------ ------------ ------ -------------- ------- ---------------- ------ ------------

# ERD-MINISTRY-TURKEY DATA

### Acknowledgements:

**Dr. Murat Nurlu** (Head, ERD, Directorate for Disaster Affairs,
Ministry of Public Works and Resettlement, Ankara, Turkey), and other
ERD staff, Ulubey Çeken, Zahide Çolakoglu, Tulay Ugras, Turgay Kuru,
Mustafa Gurbuz, Aytac Apak, Ugur Kokyer, Celal Cinar, Bekir Tuzel, Murat
Beyhan, Engin Coruh, Engin Inan.

### Data Particulars:

1.  The data in this directory is provided by ERD (Earthquake Research
    Department of the Ministry of Public Works and Reconstruction,
    Ankara, Turkey).

2.  The data covers the 17 August 1999 Izmit earthquake main-shock and
    aftershocks and the 12 November Duzce earthquake main-shock.

3.  The original data sets were provided in ASCII format.

4.  All data are acceleration data. The units are in mG (0.001 g).

5.  Each new ASCII data file contains three component of recorded motion
    for each station and each event. Each component is separated and
    identifiable from the other two by a short header that
    indicates, (a) the component orientation, (b) total length of
    record, (c) sampling interval,and (d) the unit of motion (cm/s or
    cm/s/s).

6.  The file names have been changed \[e.g. 08221431.ylv\]. The first
    two numbers refer to the month (08), the next pairs of numbers refer
    to day (22), hour (14) and minute (31) respectively.

7.  The general geotechnical descriptions of the stations are provided
    by ERD staff.

8.  The coordinatels and related station descriptions have been compiled
    from the original record files.

9.  No corrections of data signals have been made. Spectral values are
    not computed or provided.

10. Since detailed instrumental informnation were not available in the
    original records, they could not be included in the tables.

11. It is noted that at least for some events and at least for two
    stations, the records are similar. The researcher is urged to make
    the comparative judgement. We have not been able to determine how
    this happened.

# ERI-KUDO-JAPAN DATA 

### Acknowledgements:

Professor Kazuyoshi Kudo,(ERI, Univ. Tokyo, 1-1-1, Yayoi, Bunkyo-ku,
Tokyo 113-0032 Japan, e-mail:
[**kudo@eri.u-tokyo.ac.jp**](mailto:kudo@eri.u-tokyo.ac.jp), Tel:
+81-3-5841-8251, Fax: +81-3-5841-5809)

### Data Particulars:

1.  The data by Professor Kazuyoshi Kudo of Earthquake Research
    Institute of University of Tokyo and his colleagues were recorded
    with Japanese manufactured data-loggers.

2.  All recorded data are acceleration units (cm/s/s).

3.  Detailed descriptions of the (a) type of instrument used,
    (b)stations and (c) procesing of recorded data are in the document
    provided by Prof. K. Kudo included in the CD-ROM.

4.  Accordingly, data processing has been done (by Professor K. Kudo) as
    follows: (a) baseline correction with average of 100 samples (during
    one second) prior to the P-wave arrival and low pass Butterworth
    filter at cut-off frequency of 25 Hz and shunt one of 40 Hz, and (b)
    only one exception of processing is the file GLA19990912213736.DAT.
    The sampling of this file was 50 Hz, therefore, cutoff and shunt
    frequencies of 12.5 and 20 Hz were used.

# IRIGM-BOUCHON-FRANCE DATA

### Acknowledgements:

**Dr. Michel Bouchon**, \[Universite Joseph Fourier, IRIGM, BP 53, 38041
Grenoble, FRANCE (33-476-828063, Fax[:]{.underline} 33-476-828-101,
e-mail: Michel.Bouchon@ujf-grenoble.fr)\] , Hayrullah Karabulut
(Bogazici University and Kandilli Observatory, Turkey), Marie-Paule
Bouin (IPG Paris, France), Michel Dietrich (University of Grenoble,
France), Cecile Cornou (University of Grenoble, France), Aybige Akinci
(Dokuz Eylul University, Izmir, Turkey) and Mustafa Aktar (Tubitak, and
Bogazici University and Kandilli Obsevatory, Istanbul, Turkey)

### Data Particulars:

1.  The data sets cover the period following 17 August 1999 Izmit
    earthquake mainshock and are identifieable as follows:

    a.  Data Set 1: Duzce (12 November 1999) main-shock and aftershock
        records at a small array near Golyaka).

        i.  The file names of duzce main-shock records start with
            "duzce" and

        ii. The file names for the aftershocks start with "af."

    b.  Data Set 2: Duzce aftershock records following the main shock --
        continuous recording of the first 16 hours at the station (487)
        \[40.74893N,30.8892E\] closest to the fault that caused the 12
        November 1999 Duzce earthquake. It should be noted that each of
        these files contain more than one event.

        i.  The N-S components are positive to the South \[S+\].

        ii. The E-W components are positive to the West \[W+\].

        iii. The vertical components are positive Up \[+\].

    c.  Data Set 3: single record at KAR (west of Golcuk) from the 13
        September 1999 aftershock. Channel 1 is N-S, Channel 2 is
        Vertical, and Channel 3 is EW\].

2.  Data Set 1 containing Duzce main-shock and aftershock recordings
    includes data for station 492 (40.742N,30.827E) that has exceeded
    0.75 g. Since the data recording parameters has been set to 0.75g
    max, those that have exceeded it have been interpolated by Fourier
    transform (Bouchon, *pers. comm., 2001*).

3.  Amplitudes of all data are in g.

4.  Sampling rate of all data is 250. Therefore sampling interval is
    0.004 seconds.

5.  The stations were deployed and operated by staff of the University
    of Grenoble and Kandilli Observatory Seismology Section.

# ITU (ISTANBUL TECHNICAL UNIVERSITY) - TURKEY DATA

### Acknowledgements:

**Professor Atilla Ansal**, Civil engineering Department, Istanbul
Technical University, Maslak, Istanbul, Turkey), Prof.Haluk Eyidogan.
Department of Geophysics, Mining Faculty, Istanbul Technical University,
Maslak, Istanbul, Turkey.

### Data Particulars:

1.  These records were obtained by Kinemetrics SSA-2 series recorders.

2.  The recorded data have been converted from binary to ASCII using
    manufacturer supplied convertor software.

3.  The original data is in volts. These have been converted into
    accelerations using the sensitivity constants supplied by ITU
    (Professor Atilla Ansal).

4.  Each new ASCII data file contains one component of recorded
    acceleration data identifiable by a small header showing (a) the
    component orientation, (b) total length of record, (c) sampling
    interval,and (d) the unit of motion (g). The file name indicates the
    station name and some non-standard event identifier.

5.  The offset information in the header information has been used to
    remove the offset from the signal.

6.  The timing of some of the records are not synchronized with UTC
    time.

7.  According to the information provided to us, the following data

    a.  ATK003, MCD0163 and ZYT003 are the 17 August 1999 Izmit
        earthquke mainshock records for station ATK, MCD and ZYT,
        respectively.

    b.  ATK4003 and ZYT4002 are the 12 November 1999 mainshock records
        for ATK and ZYT, respectively.

# KOERI DATA (KANDILLI OBSERVATORY AND EARTHQUAKE RESEARCH INSTITUTE, BOSPHORUS UNIVERSITY, ISTANBUL, TURKEY)

Acknowledgements:

<http://www.koeri.boun.edu.tr/earthqk/earthqk.html>

### Data Particulars:

1.  All data included in this compilation have been downloaded from :

> <http://www.koeri.boun.edu.tr/earthqk/earthqk.html>.
>
> The data sets included in this compilation are those of the main
> shocks for the 17 August 1999 Izmit and 12 November 1999 Duzce events.
> It is known that, in addition to the main-shock data, KOERI has
> collected aftershock recordings following both earthquakes of 1999.
> While this CD-ROM was being completed, the complete data set has been
> released by KOERI separately during April 2001 (M. Erdik, *pers. comm.
> 2001*).

2.  Station information (coordinates) on KOERI deployments included in
    the file KOERI_STATION_INFO.xls are tabulated from the available
    information on the URL mentioned above.

3.  The data sets are kept in their original formats as downloaded from
    the URL.

4.  The users should check the orientations of some of the tri-axial
    accelerographs that are stipulated to be different than those
    provided on the web-page. The user is cautioned and exact
    orientations of these accelerographs should be obtained from the
    KOERI contact persons or recently released KOERI data CD-ROM.

# LAMONT-DOHERTY EARTHQUAKE OBSERVATORY \[LDEO\] DATA

### Acknowledgements:

**Dr. Leonardo Seeber,** (Lamont Doherty Earth Observatory of Columbia
University \[LDEO\], Palisades, NY 10964; <nano@ldeo.columbia.edu>\],
John G. Armbruster, (LDEO), Naside Ozer (The University of Istanbul,
Geophysical Engineering Department, 34850, Avcilar, Istanbul, Turkey),
Mustafa Aktar (Tubitak, and Bogazici University and Kandilli Obsevatory,
81220 Cengelkoy Istanbul, Turkey), Serif Baris (Kandilli Observatory of
Bogazici University, 81220, Cengelkoy, Istanbul), David Okaya
(University of Southern California, Los Angeles, CA 90089),

Yehuda Ben-Zion (University of Southern California, Los Angeles, CA
90089), Ned Field (USGS. Pasadena, Ca. -- formerly, SCEC, University of
Southern California, Los Angeles, CA 90089)

Special acknowledgements are reiterated for the (a) important assistance
of Serif Baris and Mustafa Aktar, both of Kandilli Observatory in
performing this work, and (b) financial support for this work from the
Southern California Earthquake Center \[SCEC\], and the National Science
Foundation.

### Data Particulars:

1.  Lamont Doherty Earth Observatory \[LDEO\] of Columbia University
    provided these records covering :

    a.  \(a\) the main-shock of November 12, 1999 Duzce earthquake and,

    b.  \(b\) aftershocks of both the August 17, 1999 Izmit earthquake
        and the November 12, 1999 Duzce earthquakes. The period of
        recording extends from end of August 1999 until February 15,
        2000.

2.  The data sets are provided in two major directories: (a) 12
    Novermber 1999 Duzce earthquake main-shock records, and (b) all
    aftershocks -- recorded following 17 August 1999 Izmit eartrhquke
    and beyond the Duzce earthquake into year 2000.

3.  The recorders used in all stations are REFTEK-72A-08 (24 bit
    channels) operating in a triggered mode. The sensors used are TERRA
    TEK Model 320 (full scale = ± 2 g).\[**[Note:]{.underline}** All
    stations also recorded high-gain three component L22 sensors.
    Stations MO (for the full deployment) and GE (only the first two
    months) recorded 3 broad-band components from Guralp CMG-40T. The
    complete data set from this experiment are expected to become
    available at the IRIS Data Center by May 2001\].

4.  The original data file names and formats have been preserved. These
    are also reflected in the original data summary Excel files. It is
    noted herein that all data are 100 samples per second.

5.  General station information including (a) station names (and
    alternative numbers for LDEO data), (b) coordinates and (c)
    geological/geotechnical descriptions are provided in station summary
    tables.

6.  No corrections and selective criteria have been applied to the data.
    The user must go through the data set to determine its
    characteristics.

7.  **The Duzce main-shock data are given as integer values and should
    be multiplied by the scale factor (in each file) to get voltage from
    the FBA sensor. Then to get \"g\" that value should be multiplied by
    0.8. The Duzce data is provided as 1 file per component per station
    per event.**

8.  The aftershocks are provided in original tar.gz format and can be
    unzipped with latest versions of Winzip. When unzipped, the data
    files are under original file names (e.g. 99.319007070375)
    indicating the (a) year \[99\], (b) Julian day \[319\], (c)
    time\[070703\], and station number \[375\]. Each record-file, has a
    short header that indicates the (a) station name \[c375\], (b)
    starting time of the record as also indicated from the file
    name, (c) total length of the record, (d) the sampling rate (100
    sps), (e) scale or unit of motion \[in g\] and for each of the three
    components, (f) the component orientations \[ in the order vertical,
    north and east\] and (g) followed by three colums of acceleartion
    data.

# USGS-GOLDEN-USA DATA

### Acknowledgements:

**Dr. Erdal Safak,** ( Geologic Hazards Team \[GHT\], USGS, Golden, Co.,
USA, *currently with USGS-Saudi Mission, Jeddah, Saudi Arabia*), Charles
Mueller (GHT), Edward Cranswick (GHT), Mark Meremonte (GHT), Dave Carver
(GHT), Tom Holzer (USGS, Menlo Park, Ca.), Mustafa Erdik (KOERI,
Istanbul, Turkey), Kemal Beyen (KOERI), Oguz Ozel (KOERI), and Muzaffer
Gul (KOERI).

### Data Particulars:

1.  There are two sources of data sets from USGS-Golden. Some duplicate
    data files exist. The user needs to be aware of the similar data in
    two data sets provided. Therefore, we divided the data sets as DATA
    SET 1 and DATA SET 2.

2.  For DATA SET 1, each new record-file, identified by its name (*e.g.*
    237L1ka.dof), has a short header that indicates, for each of the
    three components, (a) the component orientation, (b) total length of
    record, (c) sampling interval,and (d) the unit of motion (cm/s or
    cm/s/s). The file name indicates the Julian date and time. The last
    letter, **a**, before the station identifier (*e.g.* dof) refers to
    acceleration. For velocity, this will be , **v**.

**\[[A SPECIAL WARNING]{.underline}: DATA SETS: xxxxxxxxxxa.ap1 and
yyyyyyyyyya.adp**

**are [acceleration data]{.underline}. However during the conversion
process, the headers of these**

**data sets are shown as CM/SEC. They should be accepted as
CM/SEC/SEC.**

**DATA SETS: xxxxxxxxxv.ap1 and yyyyyyyyyv.adp are velocity data and the
headers**

**correctly provide the units as CM/SEC.\]**

3.  For DATA SET 2, the information table is organized from the headers
    of the records. Components of each record are shown by different
    extensions on the filename of the record (i.e. .001, .002, etc.).
    There are two types of records under this folder: 3-channel
    acceleration or 6- channel acceleration-velocity records. In the
    6-channel case, channels 4, 5 and 6 represent the velocity channels.

4.  Records that clearly show distinct and clear errors have not been
    included into the data set. Erroneous recording are described as
    false triggers, files that contain no signals and files that have
    all components clipped or exhibit clear instrumental errors.

5.  The original data files were in binary format. The data files were
    converted into ASCII format using USGS-GOLDEN written software
    "vec'.

6.  Each new ASCII data file contains three component of recorded motion
    for each station and each event. Each component is separated and
    identifiable from the other two by a small header.

7.  Sampling interval for all USGS-Golden data is 0.01 s.

8.  No corrections of data signals have been made. Spectral values are
    not computed or provided.

9.  There is a detailed table for each event that shows the stations and
    instrument characteristics.

10. There is no detailed available geotechnical information related to
    the USGS-Golden data.

11. The components are described by azimuthal angles. These are shown in
    the headers as:

> 000/000 UP-DOWN
>
> 090/000 NORTH-SOUTH
>
> 090/090 EAST-WEST.

# USGS-MENLO-USA DATA

### Acknowledgements:

**Dr. Mehmet Çelebi**, Earthquake Hazards Team \[EHZ\], USGS, 345
Middlefield Rd. Menlo Park, Ca. 94025, Christopher Dietel, EHZ, Gary
Glasmoyer, EHZ, Aydin Mert (KOERI-Istanbul)

### Data Particulars:

1.  The number of records provided in this group are considerably less
    than the number of recorded events. False and faulty triggers have
    been sieved out. The tables reflect those records with signals that
    the researcher will have to further look into before using them.

2.  The original data files are in binary format.

3.  The file names follow GEOS format and indicate the date of the
    event, UTC time and the component. {e.g. 257K17C1.FOC stands for
    Julian Day 257, \....., Station FOC\] . Each record is identified by
    computer filename, a unique 13-character string constructed from the
    start-of-record time (UTC), component, and station name: characters
    1-3 = day of year (001-366), characters 4-5 = hour (00-23),
    characters 6-7 = minute (00-59), character 8 = second code (A-T,
    where A = 0.000-2.999, B = 3.000-5.999, *\...*, T = 57.000-59.999),
    character 9 = component code (1 for vertical-component acceleration,
    2 and 3 for horizontal-component acceleration, 4 for
    vertical-component velocity, 5 and 6 for horizontal-component
    velocity), character 10 = \'.\', and characters 11-13 = station
    name. \[*See also
    http://nsmp.wr.usgs.gov/geos/LPE/OFR_90-503/Loma_Prieta.html#Sensor
    Orientations\].*

4.  The records contained in the data base are arranged so that each
    record-file represents one event for one component of motion at one
    station. These are tabulated in the excel files specific to
    USGS-Menlo.

5.  Each new ASCII record-file, identified by its name, has a short
    header that indicates (a) the component orientation, (b) total
    length of record (number of data points), (c) sampling
    interval,and (d) the unit of motion (cm/s or cm/s/s). For example,
    sampling interval for all USGS-Menlo data is 0.005 s.

6.  No corrections of data signals have been made. Spectral values are
    not computed or provided.

7.  For each source of data, a specific file describes the station
    identity, coordinates, and event time if available.

8.  Detailed geotechnical description of the stations are not available.
    However, all deployments related to USGS-Menlo data set are on
    alluvial ground. The depth and particular log information on any
    site is not known.

[^1]:
    #######  EHZ, USGS (MS977), 345 Middlefield Road, Menlo Park, Ca. 94025 USA.

[^2]: Earthquake Enginnering Research Inst., Middle east Technical Univ.
    Ankara, Turkey

[^3]: Istanbul Technical University, Istanbul, Turkey

[^4]: KOERI, Bosphorus University, Cengelkoy, Istanbul, Turkey

[^5]: ^^ Çelebi, M. , Toprak, S., and Holzer, T., 1999 and 2000,
    Strong-Motion, site-Effects and Hazard Issues in Rebuilding Turkey:
    in Light of the 17 august 1999 earthquake and its aftershocks ,
    invited paper, PROC. ITU Conference on Marmara Earthquake of August
    17, 1999: Scientific Assessments and Recommendations for Rebuilding,
    Istanbul Technical University, Istanbul, Turkey, 2-5 December 1999.
    **\[also selected and published in International Journal for Housing
    Science and its Applications (IAHS), v. 24, n. 1, pp.21- 38 and in
    Special Volume titled "The 1999 Izmit and Duzce Earthquakes:
    Preliminary results (eds. A. Barka, O. Kozaci, S. Akyuz and E.
    Altunel), pp. 247-263, 2000\].**