Next Generation Attenuation
Models for Central & Eastern US
(NGA-East)
Stakeholder Workshop: Introduction
Yousef Bozorgnia, Ph.D., P.E.
PEER Associate Director
March 7, 2008
Acknowledgments
Nuclear Regulatory Commission (NRC)
US Geological Survey (USGS)
National Institute of Standards &
Technology (NIST)
Agenda
9:00
9:15
9:35
10:10
Introduction (Yousef Bozorgnia)
NRC Perspective for NGA-East (Ann Kammerer, Jon Ake)
Need for NGA-East: National Hazard Maps for CEUS; Status, Plans, and
Issues (Mark Petersen)
Need for NGA-East: EPRI CEUS Ground Motion Report; Summary and
Issues (Norm Abrahamson)
10:45
Break
11:00
Need for NGA-East: Issues Related to Ground Motion Database for
CEUS (Chris Cramer)
Need for NGA-East: Recent Developments in Ground Motion
Simulations for CEUS (Paul Somerville/Rob Graves)
11:35
12:10
Lunch
1:10
Need for NGA-East: Recent Developments in Ground Motion Models
for CEUS (Ken Campbell)
Review of Tentative Plan for NGA-East (Ann Kammerer, Jon Ake,
Yousef Bozorgnia, Ken Campbell, Norm Abrahamson)
Discussions (All)
Adjourn
1:45
2:20
3:00
Purpose of This Stakeholder Workshop
To give an overview of:



Current status of ground motion (GM)
estimates in CEUS
Recent developments in GM predictions in
CEUS
Tentative plan for NGA-East
To invite you to join NGA-East:


As a co-sponsor
In the planning phase, or technical phase
Need for NGA-East
For CEUS, the attenuation models are a
major source of uncertainty for seismic
hazard calculations. This can be
improved by:



Expanding a database of recorded ground
motions recorded in, and simulated for,
Stable Continental Regions
A coordinated effort to develop a
consistent, yet independent, set of
attenuation models for CEUS
Including supporting R&D efforts
This Follows Successful Program of NGA-West
A multidisciplinary
program, coordinated
over five years
Bringing together:
San
Diego
State U.
UC
Santa
Barbara
UC
Berkeley
USGS
Student
U. Nevada
geologists,
seismologists,
geotechnical
engineers,
structural
engineers, and
users of ground
motion models
Researchers, and
practitioners
Private
Industry
Caltrans
USGS
Private
Industry
Compiled One of the Largest Uniformly-Processed
Strong-Motion Databases in the World
There are more than 100 variables describing
source/path/site conditions of a record:
6 types of distance
measures
4 site classification
schemes
Estimated VS30 for
most of recording
sites
HW/FW classes
The database is fully available to the public
NGA-West Attenuation Models
Ground motion
parameters:




Magnitude range:
 5.0 - 8.0+
Horizontal
components
Distance range:
PGA, PGV, PGD
Fault Mechanism:
Pseudo spectral
acceleration
 Strike-Slip
 Reverse
 Normal
Period: 0 - 10 sec
Site Effects
 0 – 200 km
Vs30 , Basin/Sediment
depth
NGA-West & National Seismic Hazard Maps
USGS has extensively
reviewed NGA, and is
adopting the NGA models
for the US National
Seismic Hazard Maps
Period=1.0 sec Spectral Acceleration
2% P.E. in 50 years
Ratio of New/Old:
Using 3 NGA relations
Versus:
2002 Hazard Maps
Abrahamson and Silva (1997),
Sadigh et al. (1997),
Boore et al. (1997),
Campbell and Bozorgnia (2003),
Spudich et al. (1999) for extensional
areas
Preliminary Map
NGA-East
It is in the planning stage
There was one technical meeting
A List of many supporting R&D projects
were compiled
There will be a public meeting in
April/May
May/June, 2008, a “road map” report
for NGA-East will be submitted to the
NRC and other potential funding
agencies
NGA-East (cont’d)
The “road map” report will include:




A timeline for the overall NGA-East
program (a five-year program)
List of supporting R&D projects
Estimated budget
…later today we will elaborate on tentative
plan for NGA-East
Agenda
9:00
9:15
9:35
10:10
Introduction (Yousef Bozorgnia)
NRC Perspective for NGA-East (Ann Kammerer, Jon Ake)
Need for NGA-East: National Hazard Maps for CEUS; Status, Plans, and
Issues (Mark Petersen)
Need for NGA-East: EPRI CEUS Ground Motion Report; Summary and
Issues (Norm Abrahamson)
10:45
Break
11:00
Need for NGA-East: Issues Related to Ground Motion Database for
CEUS (Chris Cramer)
Need for NGA-East: Recent Developments in Ground Motion
Simulations for CEUS (Paul Somerville/Rob Graves)
11:35
12:10
Lunch
1:10
Need for NGA-East: Recent Developments in Ground Motion Models
for CEUS (Ken Campbell)
Review of Tentative Plan for NGA-East (Ann Kammerer, Jon Ake,
Yousef Bozorgnia, Ken Campbell, Norm Abrahamson)
Discussions (All)
Adjourn
1:45
2:20
3:00