International Conference on Soil Liquefaction, November 3-4, 2003

1. Institute of Geophysics, National Central University, Chung-Li, Taiwan

2. Seismology Center, Central Weather Bureau, Taipei, Taiwan

Estimation of Strong Motion Response Spectra from Weak Motion Data for Earthqu

akes in Taiwan

Yi-Ben Tsai1 and Hsiao-Ling Chao2

Outlines of my presentationTwo seismic strong motion networks in Taiwan

＊ 80-station real-time network for rapid reporting.＊ 650-station free-field network for dense coverage.

Highly repeatable local site response of ground motion＊ Moderate earthquakes up to M5.8.＊ Large Chi-Chi aftershocks up to M6.5.

Testing results from M7.6 Chi-Chi earthquake data＊ Very reliable for distant stations.＊ Reliable for near-source stations with some exceptions.

Conclusion＊ Combination of the two networks can provide rapid and

reliable estimation of strong ground motion response spectra.

Purpose: To make use of two excellent strong-motion networks for rapid mapping of dense strong-motion distributions.

For timeliness: Taiwan Rapid Earthquake Information Release System.

For dense coverage: Taiwan Strong Motion Instrumentation Program Network .

Data analyzed: Chi-Chi earthquake,M7.6,396 stations.

6 Chi-Chi aftershocks ,M6.3-6.5,331-375 stations.

Chiayi earthquake, M5.8,336 stations.

Rayli earthquake, M5.7,231 stations.

Event

No.Origin time

(UT)Lat. (°N)

Long. (° E)

Depth (km)

MagnitudeStation

No.ML MW

EQ11999/09/20

17:47:15.8523.853 120.815 8.0 7.06 7.6 396

EQ21999/09/20

18:03:40.8323.806 120.850 9.97 6.26 6.3 331

EQ31999/09/20

18:11:52.7323.899 121.031 5.29 6.35 6.4 366

EQ41999/09/20

18:16:16.4823.866 121.059 8.36 6.33 6.4 357

EQ51999/09/20

21:46:37.3523.564 120.904 4.39 6.22 6.4 345

EQ61999/09/22

00:14:40.5123.826 121.047 15.59 6.47 6.4 375

EQ71999/09/25

23:52:49.5123.826 120.994 20.90 6.44 6.5 367

EQ81999/10/22

02:18:56.5523.496 120.422 23.14 6.07 5.8 336

EQ91998/07/17

04:51:15.0223.503 120.664 5.71 5.90 5.7 231

* means the record in TREIRS station is replaced by the record in free-field station.

Area TREIRS stationFree-field station (reference station)

CHY

TWL

TAI1

PNG

CHY081

CHY078

CHY075

TCUHSN

TCU

TCU081

TCU082

KAUKAU

SGL

KAU045

KAU048

TTNCHK

TTN

TTN014

TTN015

HWAHWA*

ESL*

HWA019

HWA020

ILAILA

TWE*

ILA049

ILA051

TAPTWA*

TWS1*

TAP067

TAP087

0.1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

eler

atio

n (g

) V

EW

NS

0.1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

eler

atio

n (g

)

0 .1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

eler

atio

n (g

)

E Q .1TA P

C H Y

TC U

TTN

K A U

H W A

ILA

0.1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

ele

ratio

n (g

)

0 .1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

ele

ratio

n (g

)

0 .1 1 10 100Frequency (H z)

0 .1

1

10

Spe

ctra

l Acc

ele

ratio

n (g

)

E Q 1,M w =7.6

E Q 2,M w =6.3

E Q 3,M w =6.4

E Q 4,M w =6.4

E Q 5,M w =6.4

E Q 6,M w =6.4

E Q 7,M w =6.5

E Q 8,M w =5.8

E Q 9,M w =5.7

V

EW

NS

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (N

AV/

OA

V)

T A P- H or iz ont al

O A V : T A P (L in, 1997) I LA (Chen, 1997) CH Y (Y ang, 1999)N A V : S ix Chichi A f t er shocks

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (N

AV/

OA

V)

I LA - H or iz ont al

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (N

AV/

OA

V)

CH Y - H or iz ont al

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (9

21/O

AV)

T A P- H or iz ont al

O A V : T A P (L in, 1997) I LA (Chen, 1997) CH Y (Y ang, 1999)921 : 921 Chich E ar t hquake

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (9

21/O

AV)

I LA - H or iz ont al

0.1 1 10 100

F r equency (H z )

- 2

- 1

0

1

2

ln (9

21/O

AV)

CH Y - H or iz ont al

-0 .1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

-0.1

0

0.1

0 40 80 120 160

-0.1

0

0.1

Acc

ele

ratio

n (

g)

T im e (sec)

TCU082 (EW )

EQ 1 (M w =7.6, R =36.66km )

EQ 2 (M w =6.3, R =43.06km )

EQ 3 (M w =6.4, R =45.73km )

EQ 4 (M w =6.4, R =50.63km )

EQ 5 (M w =6.4, R =69.04km )

EQ 6 (M w =6.4, R =52.35km )

EQ 7 (M w =6.5, R =52.52km )

EQ 8 (M w =5.8, R =76.52km )

EQ 9 (M w =5.7, R =71.77km )

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 122

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 006

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)T CU 059

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 048

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 070

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 0 8 2

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 089

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 0 72

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 017

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 0 74

0921 ChichiT CU H or iz ont al- component

O bser vedCalculat ed

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 039

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T CU 110

TR EIR S sta tions

0921 ChichiCH Y H or iz ont al- component

Calculat edO bser ved

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)CH Y 019

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 022

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 070

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 014

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 058

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 012

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 079

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 0 67

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 046

0.1 1 10 100F r equency (H z)

0.1

1

Sa

(g)

CH Y 080

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 002

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

CH Y 004

TR E IR S sta tions

0.1 1 10 100

F r equency (H z )

0.01

0.1

Sa

(g)

KA U 0 06

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 017

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 032

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 085

0.1 1 10 100

F r equency (H z )

0.001

0.01

0.1

Sa

(g)

KA U 038

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)

KA U 081

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 0 74

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 077

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 047

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 054

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)

KA U 008

O bser vedCalculat ed

0921 ChichiKA U H or iz ont al- component

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

KA U 050

TR E IR S sta tions

0921 ChichiT T N H or iz ont al- component

Calculat edO bser ved

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)

T T N 050

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 003

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 018

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 025

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 024

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)T T N 023

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 005

0.1 1 10 100F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 0 33

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 002

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 001

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 020

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T T N 051

TR E IR S sta tions

0921 ChichiH W A H or iz ont al- component

Calculat edO bser ved

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)

H W A 002

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 039

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 034

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 032

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 020

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 017

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 051

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 05 0

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 012

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 025

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 056

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

H W A 058

TR E IR S sta tions

0921 ChichiI LA H or iz ont al- component

Calculat edO bser ved

0.1 1 10 100F r equency (H z)

0.01

0.1

1S

a (g

)I LA 0 07

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

I LA 0 10

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

I LA 0 2 4

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

I LA 0 4 6

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

I LA 0 3 0

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)I LA 0 37

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

I LA 0 42

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

I LA 0 56

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

I LA 0 03

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

I LA 0 54

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

I LA 0 01

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

I LA 0 15

TR EIR S sta tions

0921 ChichiT A P H or iz ont al- component

Calculat edO bser ved

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 2 0

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 2 8

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T A P0 4 3

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T A P0 5 3

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T A P0 2 4

0.1 1 10 100

F r equency (H z )

0.01

0.1

1S

a (g

)

T A P0 03

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 21

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T A P103

0.1 1 10 100

F r equency (H z )

0.01

0.1

1

Sa

(g)

T A P0 59

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 84

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 0 7

0.1 1 10 100F r equency (H z)

0.01

0.1

1

Sa

(g)

T A P0 41

TR EIR S sta tions

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

T A P- H or iz ont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

I LA - H or izont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2ln

(OBS

/CA

L)T CU - H or iz ont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

H W A - H or iz ont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

CH Y - H or iz ont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

KA U - H or iz ont al

0.1 1 10 100F r equency (H z)

- 2

- 1

0

1

2

ln (O

BS/C

AL)

T T N - H or izont al

Conclusion

Combination of the two seismic networks can provide rapid and reliable estimation of strong ground motion response spectra for earthquakes in Taiwan.

Thank you very much