1. Yousef Bozorgnia, Ph.D., P.E.
Subduction Ground Motion Prediction Equations (GMPEs): Current Status and Plan for the Future
Yousef Bozorgnia, Ph.D., P.E.
Executive Director,
Pacific Earthquake Engineering Research Center (PEER),
University of California, Berkeley

2. Commonly Used Subduction GMPEs

3. Subduction GMPEs
As part of a research project, PEER compiled the commonly used subduction GMPEs
Examined their attributes (databases, range of applicability,…)
Compared the attributes and predicted response spectra

4. Commonly Used Subduction GMPEs
BC Hydro [2012]: Worldwide
Arroyo et al. [2010]: Interface model for Mexico (complementary to Garcia et al. [2005])
Atkinson & Boore [2003]: Worldwide
Garcia et al. [2005]: Intraslab model for Mexico (complementary to Arroyo et al. [2010])
Kanno et al. [2006]: Japan
Lin & Lee [2008]: Taiwan
McVerry et al. [2006]: New Zealand
Youngs et al. [1997]: Worldwide
Zhao et al. [2006]: Japan

5. Commonly Used Subduction GMPEs(page 1)
MODEL
RECORDS
EVENTS Mw
DIST. (km)
H (km)
SITE Parameters
BC Hydro (2012)
Interface 1378 Intraslab 3946
Interface 46 Intraslab 76
Interface Intraslab
Interface Intraslab 34 – 991
Interface < 30 Intraslab > 30
Continuous (Vs30)
Arroyo et al (2010)
Interface
418 40
10 – 29
N/A (NEHRP B only)
Atkinson & Boore (2003)
Interface 349
Intraslab + crustal
761
Interface 49
Intraslab
+ crustal 30
Interface
Intraslab
Interface 5 – 420
34 – 575 (r300)
Interface < 50
50 – 100
4 (Vs30; NEHRP B to E)
Garcia et al. (2005)
267 16
40 – 400
(m75)
Kanno et al. (2006)
Interf. + cr Intraslab 8150
Interf. + cr. 83 Intraslab 111
Interf.+ cr Intraslab 5.5 – 8
Interface Intraslab 30 – 500
Shallow < 30 Deep 5

6. Subduction GMPEs pre-selected (page 2)
Commonly Used Subduction GMPEs(page 1)
MODEL
RECORDS
EVENTS Mw
DIST. (km)
H (km)
SITE Parameters
Lin & Lee (2008)
Interface 873
Intraslab 3950
Interface 17
Intraslab 37
Interface
Intraslab 4.1 – 6.7
Interface
Intraslab
Interface
Intraslab
2 (Vs30; NEHRP B,C or D,E)
McVerry et al. (2006)
535
Subduct. + crustal
Interface 6 Intraslab 19
5.08 – 7.09
Interf. 15 – 24
Intrasl
3 (NZ classes)
Youngs et al. (1997)
Interface 181
Intraslab 53
Interface 57 Intraslab 26
Interface
Intraslab
Interface Intraslab 45 – 774
10 – 229 (not distinguished)
2 (Rock/Soil)
Zhao et al. (2006)
Interface 1508
Intraslab 1725
Crustal 1285
289 (not
distinguished)
(not
(not
Interf
15–162 (c125)
5 (HR + 4 Jap. Rail. Ass., Tg) 6

7. GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012
Comparison of Response Spectra
Interface
GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012 7

8. GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012
Comparison of Response Spectra
Intraslab
GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012 8

9. GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012
Sigma
Interface
GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012 9

10. GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012
Sigma
Intraslab
GEM – PEER GLOBAL GMPEs - Plenary Workshop Istanbul, 16 – 18 May 2012 10

11. Observations on Existing Subduction GMPEs
All existing GMPEs were developed before the 2010 Chile and 2011 Japan subduction earthquakes
Except one (BC Hydro) that the model was adjusted based on the new data
Some GMPEs are based on very old databases
Median predictions and standard deviations of some GMPEs can be very different than others

12. Latest GMPE: BC Hydro Model
Combined available data through 2007
– Youngs et al (1997) - global
– Atkinson & Boore (2003) - global
– Zhao et al (2006) - Japan
– Lin and Lee (2008) – Taiwan
– Macias & Atkinson (2009) – Central America
– Other available data
– About 6000 recordings from 292 earthquakes in full set
2010 Chile and 2011 Tohoku
– Not included in data set, but model adjusted based on these data
Ref.: Abrahamson, March 2012, Seattle

13. Model Features Magnitude Scaling
Includes break in magnitude scaling at large magntiudes (C1) based on simulations
Revised based on 2010 Chile and 2011 Tohoku
Depth
Only applies to slab events
Site
VS30 with non-linear site response based on AS08 and CB08 NGA-West models
Forearc/backarc
Includes different rates of attenuation for forearc and backarc sites
Sigma
Both traditional and single-station sigma
Epistemic Uncertainty
Includes range of constants to capture range of constant terms from different regions
Ref.: Abrahamson, March 2012, Seattle

14. BC Hydro Model: Magnitude Scaling
Ref.: Abrahamson, March 2012, Seattle

15. Plan for the future: Next Generation Attenuation for Subduction Earthquakes NGA-Sub

16. NGA-Sub
PEER has just initiated a multidisciplinary multi-year research program to develop Next Generation Attenuation models for Subduction earthquakes: NGA-Sub
NGA-Sub has three parallel phases

17. NGA-Sub: Phase I Collection of recorded data and metadata from the
Feb Maule, Chile (M 8.8), and
March Tohoku, Japan (M 9.0)

18. Courtesy: Yokota, et al (2011)
NGA-Sub: Phase I
For Tohoku EQ, PEER already processed:
More than recordings for the main shock (three- component each)
7 foreshocks (about recordings total)
45 aftershocks from M 6–7.7 (> recordings)
Courtesy: Yokota, et al (2011)

19. Courtesy: Yokota, et al (2011)
NGA-Sub: Phase I
For Tohoku EQ:
In collaboration with Japanese colleagues we have already received another set of:
1,190 recordings from JMA and other local networks for the main shock
In the entire set:
PGA > 0.5g was recorded at 210 sites
PGV > 50 cm/sec was recorded at 110 sites
Courtesy: Yokota, et al (2011)

20. NGA-Sub: Phase I Phase I: For the 2010 Chile EQ:
Data have been collected
But not yet processed
Dr. Rob Kayen (of USGS) will travel to Chile to carry out surface-wave site measurements at recording sites where there is no soil measurement
Collaborative efforts among PEER, USGS, and University of Chile
At the PEER side: UC Berkeley, UCLA, PEA, Individual Experts

21. NGA-Sub: Phase I
Phase I: Comparison of the data with current GMPEs used in the USGS National Seismic Hazard Map for subduction area
Phase I is funded by USGS/NEHRP; and PEER Transportation Systems Program
Started Jan 2012; will be completed by Early 2013

22. Reference: Tokachi-Oki EQ, by Macias, Atkinson, and Motazedian (2008)
NGA-Sub: Phase II
Phase II: Collection and processing of data and metadata from other subduction earthquakes worldwide:
Other Japan EQs, e.g., 2003 Tokachi- Oki EQ, M 8.3
Alaska, Chile, Mexico, Peru, Taiwan, CSZ, …
Collect and process aftershock data
Reference: Tokachi-Oki EQ, by Macias, Atkinson, and Motazedian (2008)

23. Reference: Tokachi-Oki EQ, by Macias, Atkinson, and Motazedian (2008)
NGA-Sub: Phase II
Phase II: Develop/update one GMPE for subduction earthquakes
Funded by FM Global
With supplemental funding from Caltrans
With in-kind from: BC Hydro, Validus Research, PG&E
To be completed by May
Reference: Tokachi-Oki EQ, by Macias, Atkinson, and Motazedian (2008)

24. NGA-Sub: Phase III Phase III:
Carry out validated simulations to fill the gap in empirical data
Develop multiple GMPEs by multiple developer teams (epistemic uncertainty)
Examine directivity,…
We are working to secure funding
To start February 2013 and complete by May 2016

25. Thank You!

26. Tohoku EQ: Largest recorded PGA= 2.8g at K-Net at Tsukidate
Courtesy: Midorikawa, et al (2012)

27. PGA; Tohoku (2011) and Chile (2010)
Courtesy: Midorikawa, et al (2012)

28. Ref.: Abrahamson, March 2012, Seattle