applicability of gmpes sshac for complex ruptures: level 3 ...€¦ · chi chi wenchuan el mayor 0...

SWUS GMC SSHAC

LEVEL 3

Carola Di Alessandro| GeoPentech Project Manager acting as Proponent Expert

Applicability of GMPEs for Complex Ruptures: Proponent Approach based

on NGA-West2 Residuals

SWUS GMC Workshop #2 – Berkeley – 10/22-24/2013

SWUS GMC SSHAC Level 3

OUTLINE

SWUS GMC Workshop #2, Berkeley, 10/22-24/2013

What are the options for accounting variations of dip and rake along strike in GMPEs?

• See Jennifer’s presentation Summarize the available empirical data • Available events in NGA-West2 with recording stations within 20-30 km

from the complex portion of the fault • Plot residuals in a informative way to capture range of available data Is it sufficient to constraint the effect?

• Proponent approach to evaluate effect of local vs average fault geometry: – Use ASK13 and CY13 models – Evaluate GoF plots to quantify effect in a simplified way – Draw conclusions for path forward


Available Empirical Data for Complex Ruptures


From WS#1 (Donahue)

Multi-Fault Events Considered:

– Borrego Mt. – San Fernando – Imperial Valley – Superstition Hills – Landers – Kobe – Chi-Chi – Hector Mine – Denali – Wenchuan – El Mayor-Cucapah – Darfield

Not included then due to no appreciable difference in rake/dip: • Kern County • Parkfield • Kocaeli • Duzce • Manjil, Iran

Further constraints: 1. Should show changes in rake and dip (not

only in strike) along the fault 2. Should have recordings within 20-30 km

from the complex portion of the fault 3. Have been selected by modelers to develop

GMPEs


Available Empirical Data for Complex Ruptures – Cont’d


Events that can be used are drastically reduced El Mayor-Cucapah Wenchuan Chi-Chi San Fernando Kobe

From WS#1 (Donahue)


Available Empirical Data for Complex Ruptures – Residuals


Delta-Rake and Delta-Dip quantification

A

B

For each records, compute difference between fault parameters (rake and dip) for the weighted average and For the closest segment

Segment Length Width Area Rake Dip Strike Ztor

0280a 18.0 12.0 216.0 -90 45 355.0 0.50

0280b 51.0 12.0 612.0 -180 75 312.0 0.57

0280c 66.0 18.0 1188.0 -170 60 311.0 0.51

0280d 9.0 6.0 54.0 -180 50 335.2 0.61

Suggested flatfile

144.0 14.4 2070.0 -164.2 62.8 318.4 0.50


Available Empirical Data for Complex Ruptures – Residuals

Histogram of Delta-Rake and Delta-Dip: event contribution

0

10

20

30

40

50

60

70

80

90

-75 -50 -30 -20 -10 -5 -2 -1 0 1 2 5 10 20 30 50 75

San Fernando

Kobe

Chi Chi

Wenchuan

El Mayor

0

5

10

15

20

25

30

35

40

45

-36 -16 -8 -4 -2 -1 0 1 2 4 8 16 36

San Fernando

Kobe

ChiChi

Wenchuan

El Mayor


Delta-Rake

Delta-Dip

N. o

f Rec

ordi

ngs

N. o

f Rec

ordi

ngs

-32 32 Labels fixed after Workshop #2


0.2-sec and 1.0-sec Residuals vs. Delta-Dip and Delta-Rake

Chi Chi – ASK13 W2 GMPE


Intra-event residuals on HW Intra-event residuals



Chi Chi – CY13 W2 GMPE





Chi Chi – CB13 W2 GMPE





Chi Chi – BSSA13 W2 GMPE





El Mayor Cucapah– ASK13 W2 GMPE



0.2 sec 1.0 sec



El Mayor Cucapah– ASK13 W2 GMPE


0.2 s

1.0 s



El Mayor Cucapah– CY13 W2 GMPE


0.2 s

1.0 s



El Mayor Cucapah– CB13 W2 GMPE


0.2 s

1.0 s



El Mayor Cucapah– BSSA13 W2 GMPE


0.2 s

1.0 s


Proponent Evaluation Method for Complex Ruptures


Suggested evaluation method: which approach has better agreement with available observations?

PSA computation (ASK13 and CY13 GMPE)

using local or average fault parameters

Evaluation of ratio among the PSA using the two approaches

Suggested evaluation method: which approach has better agreement with available observations? - CONTD

Adjustment of intra-event residuals obtained using local parameters to account for the ratio




Suggested evaluation method: which approach has better agreement with available observations? - CONTD

Evaluation of mean residuals using the two approaches

– Standard deviation and 90% confidence interval are also computed (not shown here)





Proponent Evaluation Method for Complex Ruptures:

Results using ASK13 and CY13


CY13

ASK13

El Mayor Cucapah

HW Presence Changes in Rake Changes in Dip Changes in SoF 4 11 (-74 to 16) 11 (-12 to 18) 3 (1 in BSSA)





CY13

ASK13

Wenchuan

HW Presence Changes in Rake Changes in Dip 5 (6 in BSSA) 10 (-27 to 28) 10 (-15 to 15)





CY13

ASK13

ChiChi

HW Presence Changes in Rake Changes in Dip 12 0 65 (-12 to 5)



Multi-Fault Ruptures: Evaluation Results Summary

Mean of the GOF for all the events

ASK13 CY13

Multi-Fault Ruptures: Evaluation Results Conclusions

• Bias plots:

– Using closest segment seems to lead to better agreement with observations in the close-in region for ASK13

– No significant effect for CY13

• Period dependency?

– Residuals are better centered at short periods using closest segment for ASK13

• What future work can be done?

– Evaluate the effect for BSSA13 and CB13 to look for systematic results

– Augment empirical data with simulations to constraint the evaluation (does it matter?)



References •Abrahamson, N. A., W. J. Silva, and R. Kamai (2014). Update of the AS08 Ground-Motion Prediction Equations Based on the NGA-West2 Data Set, Earthquake Spectra, (in press). •Boore, D. M., J. P. Stewart, E. Seyhan, and G. M. Atkinson (2014). NGA-West2 Equations for Predicting Response Spectral Accelerations for Shallow Crustal Earthquakes, Earthquake Spectra, (in press). •Campbell, K. W. and Y. Bozorgnia (2014). NGA-West2 Campbell-Bozorgnia Ground Motion Model for the Horizontal Components of PGA, PGV, and 5%-Damped Elastic Pseudo-Acceleration Response Spectra for Periods Ranging from 0.01 to 10 sec, Earthquake Spectra, (in press). •Chiou, B-S.J. and R. R. Youngs (2014). Update of the Chiou and Youngs NGA Ground Motion Model for Average Horizontal Component of Peak Ground Motion and Response Spectra, Earthquake Spectra, (in press). •Di Alessandro, C. and Abrahamson, A. (2013). Ground motion for complex multi-fracture. Proceedings of IASPEI General Assembly, Goteborg July 2013 – paper S201bS1.04 •Donahue, J (2013).Data to Constrain GMPEs in Critical Ranges –Multi-Fault Ruptures, Presentation to SWUS GMC Workshop #1

applicability of gmpes sshac for complex ruptures: level 3 ...€¦ · chi chi wenchuan el mayor 0...

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