processed strong-motion records limon costa rica eq 22 april 1991

PROCESSED STRONG-MOTION RECORDS FROM THE LIMON, COSTA RICA EARTHQUAKE OF 22 APRIL 1991

R. B. DARRAGH T. Q. CAO C. H. CRAMER A. F. SHAKAL California Strong Motion Instrumentation Program

G. SANTANA Laboratorio de Ingeniería Sísmica Universidad de Costa Rica

Report Nº OSMS 95-08

California Strong Motion Instrumentation Program

California Department of Conservation Division of Mines and Geology

Office of Strong Motion Studies 801 K Street, MS 13-35, Sacramento, California 95814-3531

October 31, 1995

CONTENTS

Introduction . . . . . . . • . . . . Earthquake Characteristics

strong-Motion Stations and Instrumentation .

Accelerogram Digitization and Processing •

Acknowledgements

References . . .

Data Availability

Appendix A - Plots of Processed Data .

Organization and Order of Plots ..

Useable Data Bandwidth

Stations:

San Isidro (ISD)

Cachi (CCH) . .

Cartage (CTG). • .

San Jose - Guatuso (GTS)

San Jose - Biblioteca UCR . (CMA).

Golfito (GLF) . .

Page

. 1

. . . 1

. . . 2

. . . 2

. . . 11

. 11

. . . . 12

. • . • 13

. • . . 13

. . . . 14

. . 15

. . • • 21

. . . . . 27

. . • . • 33

. . . . . . 39

• • • • 4 5

San Jose - Hotel Aurola (AUR) (S6tanojBasement) ...... 51

San Jose - Hotel Aurola (AUR) (Piso 15/Floor 15) 57

San Jose - Banco Nacional (BNC) (S6tanojBasement) ..•.. 63

San Jose - Hatillo (HTO)

Quepos (QPS) . .

Alajuela (ALJ)

. . . . . . . . . . . . . ,· .

• • • 69

. 75

81 ..

Puriscal (PCL)

san Ramon ( SRM) .

. . . . . . . 87

93

INTRODUCTION

strong-motion records were recovered from 15 accelerographs at 14 stations operated by the Strong Motion Instrumentation Program of the Earthquake Engineering Laboratory (EEL) at the University of Costa Rica (Santana and others, 1991) following the damaging Limon, Costa Rica earthquake of April 22, 1991. The sites range in epicentral distance from 73 to 160 km; peak horizontal accelerations at ground level ranged from 0.03 to 0.27 g. The accelerograms are characterized by long duration of strong shaking, of approximately 30 seconds.

An extensive strong motion data set from a moment magnitude (Mw) 7.5 earthquake is rare. Because of the importance of these data not only to Costa Rica but also to California, the California Strong Motion Instrumentation Program (CSMIP), in cooperation with the University of Costa Rica, digitized and processed these data for distribution to engineers, seismologists and others concerned with the seismic safety problem. This processed data is the second extensive set of data from an earthquake with magnitude between the magnitude 7 Lorna Prieta earthquake and the magnitude 7.8 Chile and Tabas, Iran earthquakes.

During the preparation of this report the magnitude 7.3 Landers, California earthquake occurred on June 28, 1992. CSMIP recovered strong-motion records from 144 stations after this earthquake (Shakal anQ others, 1992). The records from the Landers, California and the Limon, Costa Rica earthquakes are both characterized by long duration~ (near 30 seconds) and significant amplitudes of acceleration, velocity and displacement at epicentral distances greater than 100 km.

The first part of this report includes a short overview of the earthquake characteristics, key aspects of the data (station distances, peak accelerations, etc.), and a description of the accelerogram digitization procedures. In Appendix A the results of the accelerogram digitization and processing are presented through a series of plots of the acceleration, velocity and displacement, and the absolute acceleration and the relative velocity response spectra.

EARTHQUAKE CHARACTERISTICS

The Limon, Costa Rica earthquake of April 22, 1991 occurred under the Caribbean coast of Costa Rica and Panama, approximately 110 km east of the Costa Rican capital of San Jppe. According to the Earthquake Engineering Research Institute, the causative fault was a thrust fault striking southeast-northwest dipping to the southwest at less than 30° (EERI, 1991). Also, the Caribbean coast of Costa Rica was uplift by 1 to 1.5 m during the earthquake. surface rupture was not observed because the projection of the fault to the surface occurs offshore.

1

In general, the earthquake caused severe damage that extended over a large region. Extensive soil liquefaction and failure was experienced in the alluvial plains in the Limon province along the Caribbean Coast. Liquefaction caused severe damage to roads, bridges, railways, ports and water systems. Damage to buildings in the Port of Limon was surprisingly light (EERI, 1991).

The Volcanological and Seismological Observatory of Costa Rica estimated the following earthquake origin time and epicenter:

Origin Time: Hypocenter:

Magnitude:

21:56:51.8 GMT (15:56 local time), 22 April 1991 9.644°N, 83.099°W, 21.5 km depth 7.5 Mw 7.6 Ms (USGS: Preliminary Determination

of Epicenters)

STRONG-MOTION STATIONS AND INSTRUMENTATION

The locations of the earthquake epicenter and the EEL strongmotion stations in Costa Rica are shown on the map in Figure 1. Records from 15 accelerographs at 14 stations were recovered; two other instruments malfunctioned (RCP in Ochomogo and INS in San Jose). All of the instruments were SMA-1's. Two of these were deployed at one station (the 17-story Hotel Aurola). All stations are between 73 and 160 km from the epicenter. Table 1 lists geographic coordinates, structure type, site geology, and peak values of motion at each of the stations.

,·'

The records from these 14 stations are shown in the Earthquake Engineering Laboratory report on the earthquake (Santana and others, 1991) and in the Earthquake Engineering Research Institute's reconnaissance report (EERI, 1991).

Fourteen of the accelerograms, from thirteen of the stations, have been digitized and processed. A maximum horizontal velocity at ground level of 20.7 cmfs was obtained for a station 94 km from the epicenter. Peak velocity for the other stations ranged from 2 to 14 cmfs at ground level. The maximum horizontal displacements at ground level ranged from 1 to 8 em.

These data are valuable for the study of ground-motion characteristics in California and Costa Rica for large magnitude and long duration earthquakes. Before the Landers earthquake, there were few records in the Joyner and Boore (1982) data set with 7.0~magnitude<8.0. The results of this cooperative EEL/CSMIP effort will significantly increase the number of digitized records in this magnitude range.

' . ACCELEROGRAM DIGITIZATION AND PROCESSING

The digitization results presented in this report were obtained using the CSMIP computer-driven optical scanning system. This facility is patterned after the system developed at the

2

11"

10"

g· .

a·

PACIFIC

SCALE

84".30"

SAN RAMml £1

[i~

0 2S SO 7S 100 km

86" as· a4·

84"00" aS4S"

0 GRECIA

UNIVERSITY OF COSTA RICA EARTHQUAKE ENGINEERING LABORATORY

MAP OF STRONG GROUND MOTION STATIONS

r.;-;l ALAJUELA ~<0 HEREDIA

IPCil ~SAtHIAGO

83"

.0

SEA

I_Rrl ~RTAGO

@.Dqr • 0

[c~~.r PARAISO

CE~ITRAL VALLEY

10"00"

- 9"4S"

Figure 1 Map of Strong Ground-Motion Recording Stations in Costa Rica

Table 1 - Summary of Processed Records from the 1991

Station Station Coordinates ___]!2.:....._ __ __;S:;.t:;.a:;.t::.:i:..:o~n.:.....::N.:..:am=a'-------- N Lat . W Long .

Site Geology

Epicentral Instrument Dist. **

Housing * (km)

80057 San Isidro - Edificio INS (ISO) 9.374

80058 Cachi - Represa ICE (CCH) 9.842

80059 Cartage - Parque Central (CTG) 9.868

80060 San Jose - Guatuso (GTS) 9 . 870

80061 San Jose - Biblioteca 9.937 Central UCR (CHA)

80062 Golfito - Hospital CCSS (GLF) 8.645

80063 San Jose - Hotel Aurola (AUR) 9.938 (Basement)

80064 San Jose - Hotel Aurola (AUR) 9 . 938 (15th Floor)

80070 San Jose - Banco Nacional (BNC) 9.937 (Basement)

80065 San Jose - Hatillo (HTO) 9.916

80066 Quepos - Centro de Salud (QPS)

80067 Alajuela - CIPET (ALJ)

80068 Puriscal - Estaci6n de Bomberos (PCL)

80069 San Ram6n - Centro Regional UCR (SRM)

* - Instrument shelter types :

9.431

10.019

9.848

10.088

Instr . shltr D - small metal box

83.708 Hard soil (sedimentary)

83 . 805 Volcanic rock (Tertiary)

83.925 Soft, recent alluvium

84.038 Rock (sedimentary)

84 . 054 Soft soil (volcanic)

83.172 Soft soil

84.078 Hard soil (volcanic)

84 . 078 Hard soil (volcanic)

84 . 082 Hard soil (volcanic)

84.099 Soft, recent alluvium

84 . 166 Rock (sedimentary)

2-story bldg .

Tunnel

Instr . shltr. D

1-story bldg .

4-story bldg .

2-story bldg.

17-story bldg.

17-story bldg.

20-story bldg .

1-story bldg ,

1-story bldg .

84 . 220 Soft soil 2- story (volcanic) bldg.

84 . 314 Soft soil 2-story (volcanic) bldg .

84 . 482 Soft soil 1- story (sedimentary) bldg .

' .

** - Distance given relative to the epicenter at 9 . 644•N , 83.099•w .

4

73

80

94

106

109

111

113

113

114

115

119

129

137

161

....

Limon, Costa Rica Earthquake.

Component Peak Peak Peak Azimuth Accel. Velocity Dis pl. Usable Data Processed Record

(de!!j.) ..J.E..2..Jt (cm[sec) ~ Bandwidth Len5th (sec)

360 0.199 -14.3 4.5 0.09-23.6 Hz 60 UP -0.171 5.5 -4.8 (0.04-11. 7 sec)

270 -0.150 -9.4 -3.8

360 0.146 -11.4 3.9 0 . 09-23.6 Hz 68

UP -0.060 -6.9 -5.5 (0.04-11. 7 sec) 270 0.093 10.6 6.2

360 0.264 20.7 -4.4 0.09-23.6 Hz 80 UP -0.135 -9.5 -4.3 (0.04-11.7 sec)

270 0.221 -17.6 8.2

360 -0.105 9.3 1.2 0.17-23,6 Hz 72

UP -0.044 -4.1 1.4 (0.04-5.9 sec) 270 -o. 077 6.0 1.8

93 -0 . 153 -10.5 -3.9 0 . 09-23.6 Hz 60

UP -0.128 -5.4 3.3 (0.04-11. 7 sec) 3 -0.196 12.3 5.3

360 -0.061 4.2 1.2 0.17-23.6 Hz 80

UP -0.027 2.2 1.0 (0.04-5.9 sec) 270 -0.047 -3.3 1.1

95 -0.072 -5.7 -2.4 0.17-23.6 Hz 80

UP -0.037 -3.6 1.5 (0.04-5.9 sec) 5 0.061 5.9 2.0

95 -0.074 -14.8 -5.8 0.17-23.6 Hz 80 UP 0.100 -6.1 1.6 (0.04-5.9 sec)

5 -0.104 -18.0 6.3

278 -0.075 -6.0 2.5 0.17-23.6 Hz 76 UP 0.075 -4.4 1.3 (0.04-5.9 sec)

188 0.070 6.2 -2.6

360 0.122 7.8 1.6 0.17-23.6 Hz 80 UP 0.056 -2.6 1.0 (0 . 04-5.9 sec)

270 0.081 6.6 -1.5

360 -0.039 -4.1 -3.5 0.09-23.6 Hz 60 UP 0.027 3.5 3.1 (0. 04-11.7 sec)

270 -0.032 5.8 4.4

360 0.111 -10.2 -2.7 0.14-23.6 Hz 80 UP -0.046 3,7 1.4 (0.04-7.35 sec)

270 -o .118 10.6 2.8

360 0.091 -7.6 -3.3 0.09-23.6 Hz 60 UP -0.064 3.9 2.5 (0.04-11. 7 sec)

270 -0.068 7.7 3.3

360 0.094 -11.2 1.4 0.17-23.6 Hz 80 UP -0.077 -5.9 0. 7 (0.04-5.9 sac)

270 -0.093 9.3 -1.7

11 Phase 1 (Volume 1) peak acceleration values.

5

University of Southern California ~Trifunac and Lee, 1979}. In this system, a direct photographic negative copy of the film accelerogram is mounted on a rotating drum, which · is scanned by a photodensitometer. The photodensitometer is mounted on a carriage moving perpendicular to the rotational direction of the drum. The resulting x-y array of optical density values is converted to raw time series through several trace-reconstruction steps. Baseline and other corrections are then applied to this raw data to obtain the acceleration data for further processing and spectral analysis. The subsequent post-digitization processing is similar to that first developed at the California Institute of Technology (Trifunac and Lee, 1973). As discussed in greater detail below, a change of operators was made to improve the instrument correction procedure at high frequencies. In addition, the results of system noise analyses are used to guide the selection of filter corner frequencies in CSMIP processing.

The accelerograms digitized for this report are from SMA-1 accelerographs having 3 channels of data recorded on a 70 mm (2.75 in) wide film. For each accelerogram, the 70 mm film also contains one or two straight-line reference traces, and two time-mark traces.

The sequence of steps in digitizing and processing a record is summarized in the following:

.· . 1. The film record, 70 mm wide and about 80 em long, is

contact-copied onto a 25 em by 25 em high-contrast photographic negative; up to four sections of the record, each approximately 22 em (22 seconds) in length, are copied onto a single negative. To facilitate subsequent reconstruction of the original record, adjacent sections are copied so that they have an overlap of approximately 2 seconds. For further details, refer to the report by Trifunac and Lee (1979).

2. The negative containing the four sections of the accelerogram is digitized into x and y coordinates by the optical scanner. The scanner sampling rate used for these records is 200 samples per centimeter in x and y. This is nominally equal to a time step of 0.005 second (200 samplesfsec) and an acceleration increment of 0.003 g.

3. The raw x,y data from the individual sections are concatenated to form continuous acceleration traces, straight-line reference traces and timing traces . .

4. Phase 1 (Volume 1} Processing. The reference traces are · subtracted from the acceleration traces to remove any spurious film-movement effects. The axis of zero acceleration is determined by assuming the record has zero mean. The time-mark traces are used to obtain an accurate time scale. The starting

6

times of the acceleration channels are adjusted so any time phasing error from one channel to another is less than 0.02 sec (i.e., less than one time increment in the Phase 2 (Volume 2 data)). The instrument sensitivities are used to scale ordinate values to accelerations. The processed record length is between 60 and 80 seconds for all the records presented in this report.

5. Phase 2 (Volume 2) Processing. The Phase 1 (Volume 1) acceleration data are interpolated to obtain exactly 200 pointsjsec sampling (100Hz Nyquist frequency). The instrumental data are corrected to true acceleration using a simple finite-difference based instrument correction operator. A high-frequency Ormsby filter with a corner frequency of 23 Hz and a roll-off termination frequency of 25 Hz is applied. The data are then decimated to 50 pointsjsec (25 Hz Nyquist). As discussed in Shakal and Ragsdale (1984), this order (instrument correction prior decimation) improves the accuracy of the instrument correction procedure at high frequencies while still using the same simple operator used in the original Caltech code (Trifunac and Lee, 1973). The acceleration data are initially corrected for long-period errors by using a low-frequency ormsby filter with a ramp from 0.05 to 0.07 Hz. Velocity and displacement are integrated from acceleration and filtered using the same low-frequency ormsby filter as for the acceleration. To prevent the introduction of spurious long-period energy through aliasing, an Ormsby filter rather than a running mean filter is used prior to the decimation associated with the long period filtering (Shakal, 1982; Shakal and Ragsdale, 1984).

6. Phase 3 (Volume 3) Processing. The response spectra for periods from 0.04 to 15 seconds and damping values of 0, 2, 5, 10 and 20 per cent of critical are calculated from the accelerations obtained in step 5. The Fourier amplitude spectral values are also computed for these periods. A preliminary plot of the pseudo-velocity (PSV) response spectrum is generated for use in filter selection.

7. The Phase 2 Processing of step 5 is repeated, but with a new low-frequency Ormsby filter to remove long-period noise in the record. The corner frequency of the filter used depends on the signal-to-noise ratio in the record and the noise level of the digitizing system. The long-period intersection of the PSV spectrum obtained in Step 6 and the CSMIP average noise spectrum shown in Figure 2 (from Shakal and Ragsdale, 1984) indicates the long-period limit of useful information. An iterative procedure is use d, with the filter corner being set at progressively s horter periods in order to remove the long .period noise while preserving as much of the signal as possible. The final value of · filter bandwidth used is shown on the titles of the plots and explained in Appendix A. The acceleration, velocity and displacement time histories obtained using this filter are the

7

final Phase 2 (Volume 2) data written on a magnetic tape and floppy disks and presented in this report.

8. The final relative velocity response spectrum (SV), relative displacement response spectrum (SD) , absolute acceleration response spectrum (SA), and Fourier amplitude spectrum (FS) are computed using the final filter settings. The pseudo-velocity response spectra (PSV) computed from SD are plotted on tripartite logarithmic paper and presented in this report. In addition, the SA spectra are plotted versus period with a linear scale.

Note that the optimal filter bandwidth is determined for each accelerogram; all accelerograms from a single earthquake are not restricted to have a single filter corner frequency. However, the same filter corner is used for all channels from a single accelerogram to make channel-to-channel comparisons convenient.

As discussed above, Figure 2 shows the average noise spectrum for the CSMIP digitization system. It is also useful to consider the noise characteristics in terms of actual time-domain amplitudes. Figure 3 shows typical noise amplitudes present in acceleration, in velocity, and in displacement time histories obtained for different long-period filter cutoff settings. For example, Figure 3 indicates that for a filter cutoff near 10 seconds, the expected noise level is near 0.002 g in acceleration, 1 cmfsec in velocity, and 1 em in displacement.

8

...-... u w (.f)

............ z. 10 .......

(.f)

L...

::> (.f)

CL

. 01

. 001

PSA (G)

10

FREQUENCY (HZ)

1 PERIOD (SEC)

SD (IN)

...-... u w (.f)

............ ~

. U

(.f)

L...

::> . 10 ~

. 01

10 . .

Fiq. 2. Noise-level spectra (PSV, 20% damping) for the CSMIP digitization syster:~ (from Shakal and Ragsdale. 1984).

9

N u w

"' ..... :E u

z Q ... 4 ex w ...J w u 1,0 u <(

..... "' 0 4 w 0..

u w VI .....

" u " u ,... ... 1-

u z w

0 " -l w w > u

<(

d' ,10 VI 0

"' <(

w Q.

PERIOD!SECI PERIOD !SEC) PERIOD (SEC I

Fig. 3. Processing noise present in a typical acceleration (left), velocity (middle) and displacement (right) record processed with a long-period filter cut-off period ranging from 0.5 sec to 15 sees (from Shakal and Ragsdale, 1984).

10.0 20.0

ACKNOWLEDGEMENTS

The accelerographs of the Strong Motion Instrumentation Program of the University of Costa Rica were installed and maintained by W. Vargas, V. Sancho, c. Segura, A. Ramirez, and J. Altamirano. The efforts of Dr. J. Gutierrez and Dr. R. Pujal are also appreciated.

REFERENCES

Earthquake Engineering Research Institute (EERI) (1991). Costa Rica earthquake of April 22, 1991 reconnaissance report, Earthquake Spectra, Vol. 7, Supplement of volume 7.

Joyner, W. B. and D. M. Boore (1982). Prediction of earthquake response spectra, U. S. Geol. Surv. Open-File Rept. 82-977, 16 p.

Santana, G., W. Vargas, V. Sancho, c. Segura, A. Ramirez and J. Sibaja (1991). Registros de acceleraciones del terremoto de Limon, 22 de Abril de 1991 (in Spanish), Laboratorio de Ingeneria Sismica, Institute de Investigaciones en Ingeneria, Universidad de Costa Rica, Report INII-58-91, SOp.

Shakal, A.F. (1982). Spectral folding in the processing of strong-motion accelerograms, (abstract), Trans. Amer. Geophys. Union, Vol. 63, p. 1037.

Shakal, A.F. and M.J. Huang (1985). Standard tape format for CSMIP strong-motion data tapes, Calif. Div. Mines and Geology, Report No. OSMS 85-03, 26 p.

Shakal, A., M. Huang, T. Cao, R. Sherburne, R. Sydnor, P. Fung, P. Malhotra, C. Cramer, F. Su, R. Darragh and J. Wampole (1992). CSMIP strong-motion records from the Landers, California earthquake of 28 June 1992, Calif. Div. Mines and Geology, Office of Strong Motion Studies, Report No. OSMS 92-09, 330 p.

Shakal, A.F. and J.T. Ragsdale (1984). Acceleration, velocity and displacement noise analysis for the CSMIP accelerogram digitization system, Proc. 8th World Conference on Earthquake Engineering, Vol. 2, p. 111-118.

Trifunac, M.D. and v.w. Lee (1973). Routine computer processing of strong-motion accelerograms, Earthquake Engineering Research Lab., Report EERL 73-03, Calif. Inst. of Technology, Pasadena.

' . Trifunac, M.b. and v.w. Lee (1979). Automatic digitization and processing of strong-motion accelerograms, Part I: Automatic digitization, Report No. 79-15 I, Dept. of Civil Engineering, Univ. of Southern Calif., Los Angeles.

11

DATA AVAILABILITY

The processed data for the CSMIP ground-response records presented in this report are available on one magnetic tape, containing Phases 1, 2 and 3 (Vol. 1, 2 and 3) data (named COSTARICA91-G). The tape is written in a standard CSMIP format similar to that of the Caltech tapes (documented in Shakal and Huang, 1985). These tapes are available in standard ASCII or EBCDIC blocked (unlabeled) coding. In addition, the Phase 2 and 3 data are available on IBM-compatible 5~" 1.2 Mb disks. These tapes and floppy disks can be obtained at nominal cost from either of the two institutions:

Data Reduction Manager Office of strong Motion Studies Strong Motion Instrumentation Program Division of Mines and Geology California Department of Conservation 801 K Street, MS 13-35 Sacramento, California 95814-3531 Phone: (916) 322-3105 Fax: (916) 323-7778

Laboratorio de Ingeneria Sismica Institute de Investigaciones en Ingeneria ·2060 Universidad de Costa Rica · Costa Rica Phone: ( 506) 224-2408 Fax: (506) 253-4911

12

APPENDIX A

PLOTS OF PROCESSED DATA

For each station, four sets of plots are presented in the following order:

1. Phase 1 (Vol. 1) data: Uncorrected accelerations. The acceleration data for the full processed length (between 60 and 80 seconds) are plotted with common amplitude and time scales of 0.3 g and 80 seconds. Three channels are plotted on one page.

2. Phase 2 (Vol. 2) data: Instrument and baseline-corrected acceleration, velocity and displacement. The data for full processed length (between 60 and 80 seconds) are plotted with equal scaling for all channels. The filter frequencies determined in the processing are indicated on the plots (see Usable Data Bandwidth). One channel of acceleration, velocity and displacement are plotted on each page.

3. Phase 3 (Vol. 3) data: Response spectra. The absolute acceleration spectra (SA) for 0%, 2%, 5%, 10% and 20% dampings are plotted against period with linear-linear scaling from 0 to 4 seconds. The spectra are plotted for periods within the Usable Data Bandwidth. Three channels are p~otted on one page.

4. Phase 3 (Vol. 3) data: Response spectra. The pseudovelocity spectra (PSV), the pseudo-acceleration spectra (PSA), and the displacement spectra (SD) are presented on a tripartite logarithmic plot for each channel for O%, 2%, 5%, 10%, and 20% dampings. The spectra are plotted for periods within the Usable Data Bandwidth. Three channels are plotted on one page.

DEFINITION OF USABLE DATA BANDWIDTH

The filter bands for each record are indicated on the plots for the Phase 2 and Phase 3 data. In standard processing, the digitized data are processed and filtered using Ormsby filters. The data are first low-pass filtered using a high-frequency filter with a corner frequency of 23 Hz and a roll-off termination frequency of 25 Hz. Then the data are high-pass filtered using a low-frequency filter with a corner frequency of 0.07 Hz and a roll-off termination of 0.05 Hz. Therefore, the Phase 2 data is the result of the digitized data being filtered by the bandpass filter H(f) with ramps as shown in the figure:

H(f)

Usable Data Bandwidth

1.0

0.7

Frequency (Hz)

The Usable Data Bandwidth is defined as the band between frequencies fa and fL, where fa and fL are the -3 dB points on the high-frequency and lowfrequency ramps, respectively. The value of H(f) is approximately equal to 0.7 for -3 dB (see Notes). The user should only use these data for analyses within this bandwidth.

Notes:

1) The values of fa and fL can be calculated from the corner frequencies (fac• fLc) and the roll-off termination frequencies (fat• fLt) used in the processing by using the formulas fH - fHc + 0. 3 * (fHt - fHc) and fL - fLc - 0. 3 * (fLc - fLt). For example, the Usable Data Bandwidth for data bandpass-filtered with ramps at 0.30 to 0.60 Hz and 23.0 to 25.0 Hz is 0.51 Hz to 23.6 Hz (0.042 to 2.0 seconds period).

2) It is common in signal processing to plot 20 log10 [H(f)) versus frequency, and express the ordinate value in decibels (abbreviated dB). Accordingly, 0 dB corresponds to a value of H(f) equal to 1; 20 dB is equivalent to H(f) = 10, and -20 dB corresponds to H(f) = 0.1. Thus, at the -3 dB frequency point, the amplitude of the transfer function, H(f) is reduced to 0.7, while the power transmitted by the filter, H2 (f), is reduced to 0.5.

14

,..... LJ1

z 0 H

0 . 3

0

~ -0 . 3 0::: 0. 3 w _I

w u u <1::

-0 . 3 0.3

CHN 1 : 0 DEG

CHN 2 : LJP

CHN 3 : 270 DEG

10

LIMON. COSTA RICA EARTHQUAKE APRIL 22. 1991 14:56 PDT SAN ISIDRO

UNCORRECTED ACCELEROGRAM 80057-56417-91239 . 01 111571.0940-QL91A057

MAX= 0. 199 G

MAX = -0. 171 G

MAX = -0. 150 G

20 30 40 50 60 70 80

TIME (SEC)

1-:z w ~

250

-250 20

-20 8

w .......... ~~ 0 _)..___..

0... (/)

1--i C\

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN ISIDRO CHN 1: 0 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-.10 TO 23.0-25.0 HZ. 80057-S6417-91239.01 120571.1658-Ql91A057

10 20 30 40 TIME (SEC)

50

MAX = -14. 3

MAX = 4. 49

60 70 80

250

-250 20

>-..--.. ,_. t-- u ""-l HW

g~ 0 ._l::::!!: wu >...._..

t-z w

-20 8

:::::2: w..--.. ~r5 0 ._j.._..

a... (f) H 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN ISIDRO CHN 2: UP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-. 10 TO 23.0-25.0 HZ. 80057-S6417-91239. 01 120571. 1658-QL91A057

10 20 30 40 TIME (SEC)

50

MAX = 5. 51

MAX = -4. 82

60 70 80

250

-250 20

>-.,..... ...... 1-0 00 HW

g~ 0 -~~ wo > ..........

1-:z w ~

-20 8

w .,..... ~Go _J ..........

0... (./)

H 0

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN ISIDRO CHN 3 : 270 DEG

INSTRUMENT-CORRECTED AND BANDPASS~FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-. 10 TO 23. 0-25. 0 HZ. 80057-56417-91239. 01 120571. 1658-QL 91 A057

10 20 30 40

TIME (SEC)

50

MAX = -146.2

MAX = -9 . 44

MAX = -3. 75

60 70 80

::§ ... 3 (/)

~ .... ..... ... ffi 2 _J UJ u u ... UJ ..... :::l

5 1 (/) ID ...

::§ ... 3 (/)

z 0 .... ..... ... ffi 2 _J UJ u u ... UJ ..... :::l

5 1 (/) ID ...

::§ ... 3 (/)

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT SAN ISIDRO .

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT .05-.10 TO 23.0-25.0 HZ. 80057-S6417-91239.01 050595.0847-QL91A057

CHN 1: 0 OEG

DAMPING VALUES: 0,2,5. 10,20X

CHN 2: UP

DAMPING VALUES: 0, 2. 5, 10, 20X

CHN 3: 270 DEG

.. DAMPING VALUES: 0, 2. 5. 10, 20X

PERIOD (SECl

19

4

4

4

SAN ISIDRO: CSMIP S/N 057

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 POT

PHASE 3 DATA: RESPONSE SPECTRA USABLE DATA BANDWIDTH: 0.09 TO 23.6 HZ

(0.04 TO 11.8 SEC)

RECORD ID: B0057-S6417-91239 .01

RESPONSE SPECTRA: PSV, PSA ~ SO DAMPING VALUES: 0,2, 5, 10,20%

10

CHN 2: UP FREQUENCY (HZ)

1 .10

100

u w Vl ...... 5 10 > Vl a.

.10 1 PERIOD ISECl

10

100

u w Vl ...... 5 10

20

. 10

10

.10

CHN 1: 0 DEG

1 PERIOD (SEC)

CHN 3: 270 DEG FREQUENCY (HZ)

1

I PERIOD ISECl

10

100

10

10

> Vl a.

u w Vl ...... % ~

> (/) c..

:z 0 I-f

0.3

!::( -0. 3 0::: 0. 3 w _.J

w u u

N <( ......

0

-0.3 0. 3

0

LIMON, COST A RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT CACHI

UNCORRECTED ACCELEROGRAM 80058-S5578-91239. 01 111971. 1 020-QL91 A058

CHN 1: 0 DEG MAX = 0. 146 G

MAX = -0 . 060 G

MAX = 0 . 093 G

-0.3 L_L_~~~_L_L_L~~~L_L_L_~~_L_L_L~~~L_L_L_~~_L_L~~~~L_L_~~_L_L~~~--L_.J 0 10 20 30 40 50 60 70 80

TIME (SEC)

-250 20

>- ......... N t-(J N ~w

g~ 0 _J~ wu >.._..

LIMON. COST A RICA EARTHQUAKE APRIL 2 2, 1991 14: 56 PDT CACHI CHN 1: 0 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-. 10 TO 23. 0-25. 0 HZ. 80058-S55 78-91239. 01 120571. 1832-QL 91 A058

MAX= 140 .9

MAX = -11 . 4

-20 ~~~~~~--~~~-L~~--~~~~~~~~J_~~~--L-~~-L~~~~J_~~~--L-~~~~--~

1-z w ~ w .........

8

~~ 0 _J.._..

a.. (/) ~

0

-8 0 10 20 30 40

TIME (SEC) 50

MAX= 3.88

60 70 80

250

z__....... ou HW

~ o:::u 0 ww _J (f)

w-......... u~ uu <(-........

-250 20

>----N t-U W HW

g~ 0 _J~ wu >-........

-20 8

1-z w ~ w__....... u~ 0 <((.) __~-........

a_ (f) H Cl

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT CACHI CHN 2: uP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-.10 TO 23 . 0-25.0 HZ. 80058-S5578-91239.01 120571 . . 1832-QL91A058

10 20 30 40

TIME (SEC)

50

MAX = -6 . 89

MAX = -5. 45

60 70 80

250

:z...--.. ou HW

~ 5~ 0 ~ U::E uu <(...___..

-250 20

>-...--.. t-U HW

g~ 0 -J::E wu >...___..

1-:z w

-20 8

~ w...--.. ~~ 0 ....J...__..

a.. U1 H 0

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT CACHI CHN 3: 270 DEG

INSTRUMENT-CORRECTED AND BANDPASS-fiLTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 05-. 10 TO 23. 0-25. 0 HZ. 80058-S5578-91239. 01 120571. 1832-QL 91 A058

10 20 30 40

TIME (SEC) 50 60

I

MAX = 86. ~

r

MAX= 10.6

MAX = 6. 19

70

(.

~ j

80

:§ c( 3 Ul

z 0 ..... ..... c(

ffi 2 ....1 UJ u u c(

UJ ..... ::> 5 1

~

:§ c( 3 Ul

z 0 ..... ..... c(

ffi 2 _J UJ

t:l c(

UJ ..... ::> 5 1 Ul Ill c(

:§ c( 3 Ul

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 POT CACHI


CHN 1: 0 DEG

CHN 2: UP

CHN 3: 270 DEG

2

PERIOD (SECI

25

DAMPING VALUES: 0,2,5. 10.20~

DAMPING VALUES: 0, 2, 5. 10, 20~

< •

DAMPING VALUES: 0, 2. 5. 10. 20~

3

4

4

CACHI: CSMIP S/N 058

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT


(0 .04 TO 11.8 SEC)

RECORD ID: 80058-S5578-91239.01

RESPONSE SPECTRA: PSV, PSA & SO DAMPING VALUES: 0, 2, 5, 10, 20%

10


1

100

u .... "' ~ 10 >

"' Q.

. 10 I 10 PER !00 ISECl

100

u UJ

"' ~ 10

&; 0.

.10

.10

26

CHN 1: 0 DEG

1 PERIOD !SEC)

CHN 3: 270 OEG FREQUENCY (HZ)

1

I PERIOD (SECl

10

.10

10

100

E "' ..... X B > "' Q.

10

N .......

:z 0 1-l

0.3 CHN 1 : 0 DEG

LIMON. COST A RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT CART AGO

UNCORRECTED ACCELEROGRAM 80059-55576-91239 . 01 111871. 1442-QL91 A059

MAX = 0. 264 G

~ -0.3 ~~~~~~_L_L~~~L_L_~~J_~_L_L~~~L_L_~~~~_L~~~--L-~~J_~_L_L~~--~ 0:::: 0. 3 w _)

w u u <(

0

-0 . 3 0.3

0

CHN 2: L.JP MAX = -0. 135 G

CHN 3 : 270 DEG MAX = 0. 221 G

-0.3 ~~~~~~_L_L~~~L_L_~~J_~_L-L~~~L_L_~~J_~_L~~~--L-L_~J_~_L_L~~--~ 0 1 0 20 30 40 50 60 70 80

TIME (SEC)

250

-250 20

>-.---... N t--U 00 HW

g~ 0 _J~ wu >.___.,

t--z w

-20 8

~ w.---... ~~ 0 _J.___.,

0... (f)

H 0

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT CARTAGO CHN 1: 0 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-. 10 TO 23 . 0-25.0 HZ . 80059-S5576-91239 . 01 012772 . 2013-QL91A059

10 20 30 40

TIME (SEC) 50

MAX = 256. 5

MAX = 20 . 7

60 70 80

250

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : ~6 PDT CARTAGO CHN 2: uP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : 05-.10 TO 23.0-25.0 HZ. 80059-S5576-91239. 01 012772. 2013-QL91A059

MAX = -123. J

-250 L_L_~~_L~_J~L_L_~~_L_L~_J __ L_L_~~_L~~--L_L_~~_L_L_J __ L_L_~~_L~_J __ L_L_~~~

20

-20 8

t-:z w ~ w...--.. ~~ 0 _I'-"" (L (f)

H a

10 20 30 40

TIME (SEC) 50 60

MAX = -9 . 49

MAX = -4 . 30

70 80

w 0

250

-250 20

>-...--.. t-U HW

g~ 0 __J~ wu >-

t-:z w

-20 8

~ w..-.. ~Go __J..._...

0... (fJ

H 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT CARTAGO CHN 3 : 27~ DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : 05-. 10 TO 23.0-25.0 HZ . 80059-S5576-91239 . 01 012772.2013-QL91A059

10 20 . 30 40

TIME (SEC)

50

MAX = 216 . 2

MAX = - 17 . 6

MAX= 8. 22

60 70 80

£!)

... 3 tf)

z 0 ..... ,_ ... ffi 2 -' UJ u u ... UJ 1-::l -' 0 tf) ID ...

:§ ... tf)

z 0 ..... 1-... a: UJ -' UJ u u ... UJ 1-::l -' 0 tf) ID ...

£!)

4

3

2

1

00

4

... 3 tf)

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 . 14: 56 POT CART AGO

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT .05-.10 TO 23.0-25.0 HZ. 80059-S5576-91239.01 050595 .0847-0L91A059

CHN 1: 0 DEG

DAMPING VALUES: 0,2, 5, 10.20X

3

CHN 2: UP

DAMPING VALUES: 0. 2, 5, 10, 20X

2

CHN 3: 270 DEG

, . DAMPING VALUES: 0, 2. 5, 10, 201

3

PERIOD (SEC)

31

4

4

4

CARTAGO: CSMIP 5/N 059

LIMON. COSTA RICA EARTHQUAKE APRIL 22. 1991 14: 56 PDT


(0. 04 TO 11.8 SEC)

RECORD IO: 80059-S5576-91239.01

RESPONSE SPECTRA: PSV, PSA & SO DAMPING VALUES: 0,2, 5, 10,20%

10


1 . 10

100

u ..... "' ..... e 10 >

"' a.

. 10 1 PER IOD ISECl

10

10

.10

. 10

32

CHN 1: 0 OEG FREQUENCY IHZI

1

1 PERIOD ISECl

CHN 3: 270 OEG

I PER 100 ISECI

. 10

10

10

100

u UJ V'J ..... "' !:< >

"' Q.

10

CARTAGO: CSMIP S/N 059



(0 . 04 TO 11 . B SEC)

RECORD ID: B0059-S5576-91239 .01

RESPONSE SPECTRA: PSV,PSA & SO DAMPING VALUES: 0, 2, 5, 10.20%

10


1 . 10

100

u w Vl ..... ~ 10 >

"' a.

.10 I PERIOD (SEC)

10

100

u "' Vl

~ 10 > Vl Q.

32

.10

. 10

CHN 1: 0 DEG

1 PERIOD (SEC)

CHN 3: 270 DEG FREQUENCY (HZl

1

1 PERIOD ISECl

10

. 10

10

10

> "' Q.

1000

100

u .... Vl ..... :c ~

>

"' c..

10

z 0 H

0. 3 CHN 1 : 0 DEG

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT SAN JOSE - GUATUSO

UNCORRECTED ACCELEROGRAM 80060-$5730-91239 . 01 111571 . 17 40-QL 91 A060

MAX = -0. 105 G

~ -0 . 3 L_~~~~_L_L_L~~--L_L_~i_J__L_L_L~~--L_L_L_i_~-L-L~~~L_L_~i_J__L_L~~~L_~

0::: 0 . 3 w _J

w u u

CHN 2 : tJP MAX = -0 . 044 G

w <!: w

....

0

-0 . 3 0 . 3

0

CHN 3 : 270 DEG MAX = -0 . 077 G

- 0 . 3 ~~~~~~_L_L~~--L-L-L_i_J__L_L_L~~--L-L_L_i_~_L_L~~~L_L_~i_J__L_L~~~L_~ 0 10 20 30 40 50 60 70 80

TIME (SEC)

250

1-z w :::2:

-250 20

-20 8

w_.-... ~~ 0 _J...__..

a._ (/)

1-i 0 "':.

- 8 0

LIMON, COST A RICA EARTHQUAKE APRIL 22, 19 91 14 : 56 PDT SAN JOSE - GUATUSO CHN 1 : 0 DEG

INSTRUMENT-CORRECTED AND BANDPASS-fiLTERED ACCELERATION, VELOCITY AND DISPLACEMENT fiLTER BAND : . 10-. 20 TO 23.0-25.0 HZ . 80060-S5730-91239 . 01 111871 . 2055-QL91A060

10 20 30 40

TIME (SEC) 50

MAX = 9. 2 9

MAX = 1. 23

60 70 80

7

250

:z...---. ou HW

~ a:::U 0 ww _J (/)

w'-... (.)~ uu <(-........

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT SAN JOSE - GUATUSO CHN 2 : UP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-.20 TO 23.0-25.0 HZ. 80060-S5730-91239.01 111871 . 2055-QL91A060

MAX = -43. 0

-250 L_~J_~_L~~~L_L_~~_L_L~~--L_l_i__L_L~_J __ L_L_i__L_L~_J __ L_L_i__L_L~~--L_l_i__L~

20

>-...---. I--(.) HW

g~ 0 _J~ l.LJ u >-........

-20 8

1--:z w ~ w...---. (.)~ 0 <((.) _J-........

0... (/)

H 0

-8 0

MAX = -4 . 06

MAX = 1. 42

10 20 30 40 50 60 70 80

TIME (SEC)

250

-250 20

>-....-... 1-U HW

g~ 0 ...J:::::i! wu >"'---"

1-z w ::::::;;:

-20 8

w....-... ~~ 0 ...J"'---" CL U1 H 0

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT SAN JOSE - GUATUSO CHN 3 : 270 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : . 10-.20 TO 23.0-25 . 0 HZ. 80060-S5730-91239.01 111871.2055-QL91A060

10 20 30 40

TIME (SEC) 50

MAX= 6.02

MAX = 1. 75

60 70 80

~

... 3 U')

z 0 .... ..... ... ffi 2 ...J UJ u u ... UJ ..... :::l

5 1 U') !Il ...

:§ ... 3 U')

z 0 .... ..... ... ffi 2 ...J UJ u u ... UJ ..... :::l

5 1 U') !Il ...

:§ ... 3 U')

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 POT SAN JOSE - GUATUSO

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT .10-.20 TO 23.0-25.0 HZ. 80060-55730-91239.01 050595 .0847-QL91A060

CHN 1: 0 DEG

CHN 2: UP

CHN 3: 270 DEG

2

PERIOD !SEC)

37

DAMPING VALUES: 0. 2. 5. 10, 201

DAMPING VALUES: 0. 2. 5. 10, 201

,• . DAMPING VALUES: 0. 2. 5. 10. 201

..._

4

4

4

SAN JOSE - GUATUSO: CSMIP S/N 060


PHASE 3 DATA: RESPONSE SPECTRA USABLE OATA BANDWIDTH: 0. 17 TO 23.6 HZ

(0 . 04 TO 5.88 SEC)

RECORD IO: 80060-S5730-91239 .01

RESPONSE SPECTRA: PSV, PSA & SO DAMPING VALUES: 0, 2, 5, 10, 20%

10


1 . 10

100

0 UJ ttl .... 5 10 > ttl a.

. 10 1 PERIOD (SEC }

10

100

0 UJ ttl

~ 10 > ttl <l.

38

10

. 10

10

.1 0


1

1 PERIOD (SEC)

CHN 3: 270 DEG FREQUENCY (HZI

1

1 PER !00 I SEC}

. 10

100

10

. 10

100

10

10

> ttl <l.

u UJ ttl .... "' ~ > ttl <l.

z 0 H

0.3 CHN 1 : 93 DEG

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE - BIBLIOTECA UCR

UNCORRECTED ACCELEROGRAM 80061-57046-91325.01 122671. 0944-QL91A061

MAX = -0 . 1 53 G

~-0.3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--L-~~~~~~~~--~ 0::: 0. 3 w _J

w 0 0 <(

CHN 2: UP MAX = -0. 128 G

-0 . 3 ~~~~~~~~~~~--L-~~J-~-L~~~~--L-~~~~~_L~~--L-~~J-~-L_L~_J~~ 0 . 3 CHN 3 : MAX = -0 . 196 G

0

- 0. 3 0 10 20 30 40 50 60 70 . 80

TIME (SEC)

250

-250 20

>-.--.. f-U HW

g~ 0 ....J::2: wu >-.........

f:z w ~

-20 8

W .--.. 0::2: 0 <t:U ....J'--"' a.. (/) H a

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT SAN JOSE- BIBLIOTECA UCR CHN 1: 93 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : 05-.10 TO 23 . 0-25 . 0 HZ . 80061-57046-91325.01 020772.1104-QL91A061

10 20 30 40

TIME (SEC)

50

MAX = -10.5

MAX = -3. 88

60 70 80

-P-......

250

-250 20

>-...--... t-U HW UU1 o-......... 0 _J~ wu >.._....

-20 8

1-z w ~ w...--.. ~a o _J..__..

D.... U1 H a

- 8 0

LIMON. COST A RICA EARTHQUAKE APRIL 22, 19 91 14: 56 PDT SAN JOSE - BIBLIOTECA UCR CHN 2: uP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 05-.10 TO 23.0-25.0 HZ. 80061-S7046-91325.01 020772.1104-QL91A061

10 20 30 40

TIME (SEC)

50

MAX = -105. 9

MAX = -5.41

MAX =· 3 . 28

60 70 80

'

250

-250 20

>-...--... 1-U HW

g~ 0 _J~ wu >-........

1-z w

-20 8

~ w..-... u~ 0 <t:U _J-........

0... (/) H 0

-8 0

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE - BIBLIOTECA UCR CHN 3 : 3 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 05-.10 TO 23.0-25 . 0 HZ . 80061-S7046-91325.01 020772.1104-QL91A061

10 20 30 40

TIME (SEC) 50

MAX= 12. 3

MAX = 5. 29

60 70 80

z 0 ..... 1-4(

ffi 2 _. UJ

13 4(

UJ 1-::l

5 1 en cc 4(

::§ 4( 3 en

~ ..... 1-4(

ffi 2 _. UJ u u 4(

UJ ..... ::l

5 1 en cc 4(

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT SAN JOSE - BIBLIOTECA UCR .


CHN 1: 93 DEG

2

CHN 2: UP

CHN 3: 3 DEG

2

PERIOD (SEC)

43

DAMPING VALUES: 0.2.5. 10,201

3

DAMPING VALUES: 0, 2, 5. 10, 201

,· .

DAMPING VALUES: 0. 2.5. 10.201

4

4

4

SAN JOSE - BIBLIOTECA UCR: CSMIP S/N 061

LIMON, COSTA RICA EARTHQUAKE APRIL 22. 1991 14: 56 PDT

PHASE 3 DATA: RESPONSE SPECTRA USABLE DATA BANDWIDTH: 0.09 TO 23 .6 HZ

(0. 04 TO 11. B SEC)

RECORD 10: B0061-S7046-91325 .01

RESPONSE SPECTRA: PSV,PSA & SO DAMPING VALUES: 0. 2, 5, 10. 20%

10

PSA (GJ

CHN 2: UP FREQUENCY IHZI

1 . 10

100

8 (/] ..... s 10 > (/] a.

.10 1 PERIOO ISECJ

10

10

.10

10

. 10

44


1

1 PEHIOO ISECl


1

I PERIOD ISECJ

10

. 10 1000

100

u UJ (/] ..... :z: H

> (/] a.

10

10

z 0 H

0. 3 CHN 1: 0 DEG

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT GOLF ITO

UNCORRECTED ACCELEROGRAM 80062-55584-91325. 01 031772. 1653-QL 91 A062

MAX= -0.061 G

~-0 . 3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--~~~~~~~~~--~ 0::: 0. 3 w _I

w (_) (_) <(

0

-0 . 3 0.3

CHN 2: L.JP

CHN 3 : 270 DEG

10 20

MAX= -0.027 G

MAX= 0.047 G

30 40 50 60 70 80

TIME (SEC)

250

-250 20

>-...-.. ~ 1- (.) 0\ HW

LIMON, COST A RICA EARTHQUAKE APRIL 22, 19 91 14: 56 PDT GOLFITO CHN 1: 0 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 10-.20 TO 23.0-25.0 HZ. 80062-S5584-91325.01 122371.2041-QL91A062

I.AAX = -57. 4

I.AAX = 4. 18

~ 0 r---~--~~~~~~~~~Nt~~~~~~~~m+~~~~~~~==~~~~~----~~=-~~--~~

Ld25 >...__,

1-:z w ~

-20 8

w...-.. ~rs o ...J...__, 0... (f)

H a

10 20 30 40

TIME (SEC)

50 60

I.AAX = 1. 21

70 80

250

LIMON. COST A RICA EARTHQUAKE APRIL 22. 1991 14: 56 PDT GOLFITO CHN 2: uP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-.20 TO 23.0-25.0 HZ. 80062-S5584-91325.01 122371.2041-QL91A062

YAX = -23. 8

-250 L-L-~~~_L~~~L_~J__L_L~_J __ L_L_~~_L~~--~L_~~_L~_J--~L_~~_L~_J __ L_L_~~~

t:z w :::::!:

20

-20 8

w....--.. ~r5 0 _J...._..

a.. (/')

H Cl

10 20 30 40

TIME (SEC) 50 60

MAX = 2. 21

MAX = 0. 95

70 80

.c-00

250

:z.--.. ou t-tLU

~ a::u 0 LULU

~ U:::E (J(J <( ..........

-250 20

>-..-.. t- (J I-ILU (_)(/) 0 .......... 0 -l:::E LUU > ..........

-20 8

tz w :::E LU.--..

lIMON. COST A RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT GOLFITO CHN 3 : 270 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: 10-.20 TO 23.0-25 . 0 HZ. 80062-S5584-91325 . 01 122371.2041-QL91A062

MAX =

MAX =

41. 9

-3. 30

MAX = 1. 13

~~ 0 r------=-==-~~~~~~~~--~~~~-+~~~~~~~~~~~~~~~~~-=~~~~------~ -l....___. a.. (/) 1-1 Cl

10 20 30 40 TIME (SEC)

50 60 70 80

:§

"" 3 (/)

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT GOLFITO .

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT . 10-.20 TO 23.0-25.0 HZ. 80062-S5584-91325.01 050595.0647-0L91A062

CHN 1: 0 DEG

DAMPING VALUES: 0,2,5, 10,201

2

CHN 2: UP

DAMPING VALUES: 0.2.5. 10,201

CHN 3: 270 DEG

.. DAMPING VALUES: 0. 2. 5, 10. 201

PERIOD (SEC)

49

4

4

GOLFITO: CSMIP S/N 062


PHASE 3 DATA: RESPONSE SPECTRA USABLE DATA BANDWIDTH: 0. 17 TO 23.6 HZ

(0. 04 TO 5. 88 SEC)

RECORD 10: 80062-S5584-91325 .01

RESPONSE SPECTRA: PSV.PSA & SO DAMPING VALUES: 0, 2, 5, 10. 20%

10

CHN 2: UP FREQUENCY IHZJ

1

100

u w Ul

' ~ 10 > <J] Cl.

. 10 1 PERIOD ISECI

10

100

> Ul Cl.

50

.10

10

. 10


1

1 PERIOD ISECI


1

I PERIOD !SEC)

10

10

100

10

> Ul Cl.

E Ul

' "' l::!

> Ul a..

LIMON, COSTA RICA EARTHQUAKE APRIL 22. 1991 14: 56 PDT SAN JOSE - HOTEL AUROLA (BASEMENT)

UNCORRECTED ACCELEROGRAM 80063-55585-91239 . 01 121995.1106-0L91A063 0. 3 CHN 1: .95 DEG MAX = -0 . 072 G

z 0 ..._. ~-0.3 ~~~~~~~~~~~~~~~~~~~L-L-L-~L-L-L-L-L-L_L_L_L_L_L_L_L-L-~~~

ffi 0.3 --'

\J1 w ,_. u u <(

CHN 2: UP MAX = -0.037 G

-0 .3 L-~~~~~~~~~~~~~~L-L-L-L-L-L-L-~L-L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_~ 0 .3 5 DEG

10 20 30 40

TIME (SEC)

MAX = 0.061 G

50 60 70 80

U1 N

250

z....-... ou HW

~ o:::u 0 ww _! (/)

l..&.J'.... U::::!: uu <...__.

-250 20

>-....-... t-U HW U(f) o-........ 0 -1:::::!: wu >...__.

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE - HOTEL AUROLA (BASEMENT) CHN 1: 95 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : . 10-.20 TO 23.0-25.0 HZ. 80063-S5585-91239.01 060372.1553-QL91A063

MAX =

MAX =

-71. 6

-5. 70

-20 ~~~~-L-L~~--L-~~~-L~~--L-~~~-L~~~L-L-~~_L~~~L-L-~~_L_L~~L-L-~~~ 8

10 20 30 40

TIME (SEC)

MAX = -2. 43

50 60 70 80

V1 w

250

:z .......... Oc..> HW

~ a:: c..> 0 ww ~ c..>::!: c..> c..> ..,;: .........

-250 20

>-....-... 1-c..> HW ( .. )(/) c::s---... 0 -~~ wu > .........

-20 8

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE - HOTEL AUROLA (BASEMENT) CHN 2 : UP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : . 10-.20 TO 23 . 0-25 . 0 HZ . 80063-55585-91239 . 01 060372. 1553-QL91A063

MAX =

MAX =

-35.4

-3.55

MAX = 1. 54

10 20 30 40

TIME (SEC) 50 60 70 80

Ln .p..

250

:z: ......... ou HW

~ o::u 0 ww -l (/) u..J'o.... u::::.;; (.)(.) <:...__.

-250 20

>-...-.. J-U HW (.)(!) o-......... 0 -I::.;; wu >...__.

-20 8

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE -HOTEL AUROLA (BASEMENT) CHN 3: 5 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : . 10-.20 TO 23.0-25 . 0 HZ . 80063-S5585-91239 . 01 060372. 1553-QL91A063

10 20 30 40

TIME (SEC) 50 60

MAX = 57.8

MAX = 5. 85

MAX :: 1. 99

70 80

§

""' 3 (/)

~ ...... .... ""' ffi 2 -' UJ (.J (.J

""' UJ .... :::1

6 1 (/) IXl

""'

§

""' 3 (/)

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 1~: 56 POT SAN JOSE - HOTEL AUROLA (BASEMENT) ·

ACCELEROGRAM "BANDPASS-FILTERED WITH RAMPS AT .10-.20 TO 23.0-25.0 HZ . 80063-55585-91239 .01 050595.0848-0L91A063

CHN t: 95 DEG

2

CHN 2: UP

CHN 3: 5 DEG

2

PERIOD (SEC)

55

DAMPING VALUES: 0.2.5. 10, 20%

DAMPING VALUES: 0, 2.5. 10. 20~

.. DAMPING VALUES: 0.2.5. 10,20~

4

4

SAN JOSE- HOTEL AUROLA (BASEMENT): CSMIP S/N 063


PHASE 3 DATA: RESPONSE SPECTRA USABLE DATA BANDWIDTH: 0.17 TO 23 .6 HZ

(0 .04 TO 5.88 SEC)

RECORD 10: 80063-S5585-91239 .01

RESPONSE SPECTRA: PSV,PSA ~SO DAMPING VALUES: 0, 2,5, 10,20%

10


1 .10

100

u .... Vl ..... 6 10 > Vl a.

. 10 1 PERIOD (SEC)

10

10

. 10

10

. 10

56

CHN 1: 95 DEG FREQUENCY (HZ!

1

1 PERIOD ISECI


1

1 PER I 00 (SEC)

. 10

10

. 10

100

10

10

> Vl a.

u UJ Vl ..... X B > Vl a.

:z: 0 ~

)

0.3 CHN 1: 95 DEG

LIMON,. COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT SAN JOSE - HOTEL AUROLA (15TH FLOOR)

UNCORRECTED ACCELEROGRAM 80064-55735-91239.01 121995 . 1106-QL91A064

MAX = -0 . 074 G

~-0.3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ffi 0 .3 _J

V1 L1.J -...J u

u <!

CHN 2: UP MAX = 0.100 G

-0.3 ~~~~~~~~~~~~L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_~ 0.3 CHN 3: 5 DEG MAX = -0 . 104 G

. 10 20 30 40 50 60 70 80 TIME (SEC)

250

:z.....-.. 00 HW

~

LIMON, COST A RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT SAN JOSE- HOTEL AUROLA (15TH FLOOR) CHN 1: 95 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-.20 TO 23.0-25.0 HZ. 80064-55735-91239.01 060372.1735-QL91A064

MAX = -70. 8

~ ~ 0 ...-.._........,..,...,.....-IN\/'-m.Jii.J""ll _J (/)

I..Lf"-... 0:::!! 00 <..__,

-250 L-L-~~~-~-~~~~--~~~L-~~-~--L-L~~--~--~L-~~-~--L~~~~L-L-~~~_L-L~-J__J~ 20

>-.....-.. U1 t--0 00 HW

~ 0 ~~~~~~~~-r++~~~HH~~~~~++~~~~~~~~~~+4~++~~+4~~~~~~~~~~ -I::!! wo >..__,

t-:z w :::!!

-20 8

w.....-.. ~~ 0 _J..__,

a... (/)

H 0

-8 0 10 20 30 40

TIME (SEC) 50

MAX = -5. 84

60 70 80

250

1-:z w ::::::E

-250 20

-20 8

w ...... ~n~ o _.J

a.. (/') 1-t C'l

-8 0

LIMON; COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE -HOTEL AUROLA (15TH FLOOR) CHN 2 : UP

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-.20 TO 23.0-25.0 HZ. 80064-$5735-91239.01 060372.1735-QL91A064

10 20 30 40 TIME (SEC)

50

MAX = -95. 8

MAX = -6. 12 .

MAX == 1. 57

60 70 80

250

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE -HOTEL AUROLA (15TH FLOOR) CHN 3: 5 DEG

INSTRUMENT-CORRECTED AND BANDPASS-fiLTERED ACCELERATION, VELOCITY AND DISPLACEMENT fiLTER BAND : . 10-. 20 TO 23.0-25.0 HZ . 80064-55735-91239 . 01 060372 . 1735-QL91A064

MAX = -100.3

-250 L-L-~~~-L-L~~~~L-L-L-~J--L-L~~~~L-L-L-~~-L-L~~~--L-L-~J-~-L~~~~~

>-...--.. t-U HW

20

g~ 0 -':::'!: w (.) > -......-

MAX= -18 . 0

-20 ~~~~~~~~--~~~-L~~~--L-~~~-L~~~L-L-~~-L~~--L-~~~-L~~--L-~~-L~

t:z w :::'!: w...-..

8

~r5 0 _,...___ CL (I) H a

-8 0 10 20 30 40

TIME (SEC) 50

MAX= 6 . 30

60 70 80

:§ 41; 3 U'l

z 0 .... 1-41;

ffi 2 ...J UJ u u 41;

UJ 1-:::J a 1 (/) a:J 41;

LIMON, · coSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 POT SAN JOSE - HOTEL AUROLA (15TH FLOOR)

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT .10-.20 TO 23.0-25 .0 HZ. 80064-55735-91239.01 050595.0848-QL91A064

CHN 1: 95 OEG

CHN 2: UP

2

CHN 3: 5 OEG

2

PERIOO (SEC)

61

DAMPING VALUES: 0.2.5. 10.201

DAMPING VALUES: 0. 2, 5, 10, 201

' . DAMPING VALUES: 0,2,5, 10,20X

3

4

SAN JOSE- HOTEL AUROLA (15TH FLOOR): CSMIP S/N 064



(0.04 TO 5.88 SEC)

RECORD ID: 80064-S5735-91239.01

RESPONSE SPECTRA: PSV, PSA & SO DAMPING VALUES: 0, 2, 5, 10. 20%

tO


t . to

toO

u .... Ill .... ~tO > Ill Q.

. 10 I PERIOD (SEC)

10

> Ul 0..

62

.to

tO

.to

CHN 1: 95 DEG

t PERIOD (SEC)


t

I PERIOD (SEC)

tO

. to toOO

tOO

8 Ill .... :z: ~

> Ill 0..

to

10

z 0 ~

0.3 CHN 1: 278 OEG

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 POT SAN JOSE - BANCO NACIONAL (BASEMENT)

UNCORRECTED ACCELEROGRAM 80070-55733-91239.01 121995.1106-QL91A070

MAX = -0.075 G

~-0.3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ffi 0.3 --'

0\ LLJ w u

u <(

CHN 2: UP MAX = 0.075 G

-0.3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 0. 3 CHN 3: 188 OEG

10 20 30 40

TIME (SEC)

MAX = 0.070 G

50 60 70 80

0\ .p..

250

:z ......... 00 1-1 LLJ

~ 0:::0 0 LLJ LLJ

~ 0~ 00 <-

-250 20

>-.......... t-0 1-1 LLJ 0(.1) 0 0'-.... _J~ wo >----

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14:56 PDT SAN JOSE- BANCO NACIONAL (BASEMENT) CHN 1: 278 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND : . 10-. 20 TO 23 . 0-25.0 HZ. 80070-S5733-91239. 01 060372. 1402-QL91A070

MAX = -72.5

MAX = -6.04

-20 L-L-L-~~~-L-L-L~--l--L-L-L-~~-L-L-L~--l--L-L-L_~_J__L_L~_J~L-L-L-~~_L-L-L~__J~

t:z 4l ~ w .........

8

0~ 0 <:O _J...__..

a... (./) 1-1 0

-8 0 10 20 30 40

TIME (SEC) 50

MAX = 2. 46

60 70 80

250

-250 20

>------. f-0 HW

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14 : 56 PDT SAN JOSE - BANCO NACIONAL (BASEMENT) CHN 2 : UP

INSTRUMENT-CORRECTED AND BANDPASS-fiLTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-. 20 TO 23 . 0-25.0 HZ. 80070-55733-91239 . 01 060372 . 1402-QL91A070

MAX = 71. 8

MAX = -4 . H

g~ 0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~---=~~~~~~--~ -l:::::ii: La..JO >---

f:z w :::::!:

-20 8

w-----.

MAX = 1. 28

~~ 0 ~~~~~~~~~~~~~~~~~~~~~-=~--~~~--~~=r~~~--~=-~----~~--~ _J..._

[L Vl 1-l C\

10 20 30 40 TIME (SEC)

50 60 70 80

"' "'

250

z .......... 0<..> HW

~ ~(.) 0 ww ~ (.)::1! (.) (.) <'-"'

-250 20

>-.......... ,_ (.) 1-IW (.)(/') 0 .......... 0 ....J::i! w<..> >'-"'

LIMON, COSTA RICA EARTHQUAKE APRIL 22, 1991 14: 56 PDT SAN JOSE - BANCO NACI ONAL (BASEMENT) CHN 3: 188 DEG

INSTRUMENT-CORRECTED AND BANDPASS-FILTERED ACCELERATION, VELOCITY AND DISPLACEMENT FILTER BAND: . 10-.20 TO 23.0-25.0 HZ. 80070-S5733-91239. 01 060372. 1402-QL91A070

MAX =

MAX =

68.0

6.20

-20 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~-L-L~~--L-~~~~~~~~~~

,_ z w ~ LLJ,........,

8

(.) ~ 0 <<..> ....J'-"' a.. (/) H 0

10 20 30 40

TIME (SEC) 50 60

MAX = -2.57

70 80

~ ....: 3 (/)

~ ..... ..... ....: ffi 2 --' UJ u u ....: UJ 1-;::l

6 1 (/) lXI ....:

~ ....: 3 (/)

LIMON, COSTA RICA EARTHQUAKE APRIL 22. 1991 14: 56 PDT SAN JOSE - BANCO NACIONAL (BASEMENT)

ACCELEROGRAM BANDPASS-FILTERED WITH RAMPS AT .10-.20 TO 23 .0-25 .0 HZ . 80070-S5733-91239.01 050595.0848-0L91A070

CHN 1: 278 OEG

2

CHN 2: UP

CHN 3: 188 OEG

2

PERIOD (SEC)

67

DAMPING VALUES: 0,2,5, 10,20~

DAMPING VALUES: 0,2,5, 10,20~

,• .

DAMPING VALUES: 0. 2. 5, 10,20~

3

4

4

4

SAN JOSE- BANCO NACIONAL (BASEMENT): CSMIP S/N 070


PHASE 3 DATA: RESPONSE SPECTRA USABLE DATA BANDWIDTH: 0 . 17 TO 23 .6 HZ

(0 . 04 TO 5 . 88 SEC)

RECORD ID: 80070-55733-91239 .01

RESPONSE SPECTRA: PSV,PSA & SO DAMPING VALUES: 0, 2, 5, 10, 20%

10

CHN 2: UP FREQUENCY (HZI

1 . 10

100

u w tn

' eto > tn 0..

.10 1 PER!OO (SECI

10

100

u w U'l

~ 10 > tn a.

68

. 10

10

. 10

CHN 1: 278 OEG FREQUENCY (HZI

1

1 PEAIOO (SECI

CHN 3: 188 DEG FREQUENCY (HZI

1

1 PER!OO ISECI

. 10

10

. 10

100

u w tn

' X .!,!

> tn 0..

10

10

processed strong-motion records limon costa rica eq 22 april 1991

Documents

california earthquake

costa rica earthquakes

plots of processed data

extensive set of data

earthquake shakal anq

data station distances

lorna prieta earthquake

data availability appendix