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Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 2
Los Alamos National Laboratory’s Seismic Hazard Characterization Program: a look
back and a path forward
Carene Larmat, Emily Schultz-Fellenz, Richard Lee, Michael Salmon, Lawrence Goen
Los Alamos National Laboratory2016 Natural Phenomena Hazard, Germantown, October 2016
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 3
LANL Seismic Hazards Program
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 4
Outline
• Where we are: • Seismic Hazard Program• Large uncertainty in the seismic hazard evaluation
• Seismic Hazard Evaluation Challenges for LANL:• Sitting on the foot-wall of a normal fault• Historically low seismicity rate• Complex environment and source-path • Unique challenge for site and topography effects.
• Activities of the Seismic Hazard Program• Overview• Trenching• Site and topography effects characterization
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 5
New Mexico Seismicity
SeismotectonicProvinces and Historical Seismicity, from 1869 to
present
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 6
LANL Seismic Design Basis Evolution• 1972 report by Dames and Moore (Investigation to support design of PF-4)
• Generic site/deterministic based
• Early 1990’s DOE requirements for Natural Phenomena Hazards• For sites with nuclear and high hazard facilities, site specific probabilistic hazard curves required• Otherwise rely upon national consensus standards
• 1995 PSHA:• Field investigations on site response and paleoseismic parameters
• Additional field work 1997-2002• Fault mapping, paleoseismic trenches Guaje Mountain, Pajarito Faults
• 2007 PSHA update (10-yr update)- Required because of new information, advancement in state-of-the-art:
• 2008-present Seismic Hazard Program Plan (rev 0)
• 2009 PSHA revision:- Modified for updated ground motion prediction equations- Refinement of vertical motion development
• 2009-present: monitoring and characterization programs
• 2018 Planned PSHA update (10-yr update)
Incr
easi
ng R
igor
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 7
Illustration of uncertainty obtained from the 2007 PSHA update
Slide 7
Seismic Hazard Curves for Peak Horizontal Acceleration, CMRR
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 8
Quaternary faults in the vicinity of LANL
Map of identified segments
Organization in a complex fault
system.
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 9
Logic Tree for the Pajarito Fault system
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 10
Comparison of Stochastic Attenuation Relationships for M 7.0 and Peak Ground Acceleration at CMRR
Illustration of the uncertainty in the medium ground motion
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 11
Ashen like soil layer amplifies seismic loads at the basement level.
Generalized Stratigraphy of Bandelier Tuff
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 12
How are we addressing these challenges:The Seismic Hazard Program Plan
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 13
Seismic Hazard Program Plan Objectives• To list and prioritize manageable work tasks that will reduce uncertainties in
our understanding of the seismic hazard at Los Alamos• Enable LANL to more cost effectively manage the associated NPH risk of LANL
operations• Improve integration of Earth science activities at LANL
Source models
Path (GMPEs)
Site characterization/Modeling
PSHA Methodology
PSHA Evaluation
Earthquake Monitoring
External review of PFS
Stochastic GMPE epistemic
P-wave nonlinear Simplified PSHA Revisit logic tree Network maintenance
RGR fault slip analysis
Vertical Seismic Profile Precariously perched objects
Revise PSHA Deploy vertical seismic array
Static stress model Support ER/EP seismic reflection survey
Extreme Sensitive motion upgrade
Mapping of SCC Additional Eqkes for kappa
Revise Method 3 Strong motion upgrade
Trenching SCC LANL velocity correlation model
Additional kappa assessment
Past, current and future activities
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 14
Activities focused on data collection
Data collection
Update PSHA
Site characterization
trenching
Shaker Base PlateShaker Base Plate
Geology mapping
Seismic monitoring
Modeling
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 15
Trenching
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 16
Trench Characterization, Documentation, and Field Interpretation
16
Geologic data indicates that seismic hazard is much greater than historic seismicity suggests. Seismic hazard is controlled by the Pajarito Fault System.
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 17
Geologic evidence for earthquake rates
The Pajarito Fault System has ruptured from 1 to 3 times in the last 10,000 years: Most recent events:
• Pajarito Fault: 1.5-2.5 ka; 6-10 ka*• Rendija Canyon Fault: >9 ka• Guaje Mountain Fault: 3-10 ka
*Could be interpreted as two events: 6-9ka and 9-11ka
Slide 17
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 18
Trench Sites & Timing
McCalpin(1999)
S a n t a F eN a t i o n a l F o r e s t
Wa t e r
EasternStrand
McCalpin(1999)Western
StrandMcCalpin (1999)
Trenches
Figu
re 4
Figu
re 3
Site 98-4
4
Site A
Site B
Site C
Site D
Site E
Site E-north(parkinglot site)
-1-106.35°-106.367°
35.8
5°35
.833
°
Phase 1 Sites
2016On LANL Lands:Site A
2017, Upon Receipt of PermitsOn SFNF Lands:Site BSite 98-4
On NPS Lands:Site E-north
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 19
Site characterization and modeling
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 20
Experiments: 2011, 2014• Use high-energy shear-wave source (T-Rex) to reduce uncertainty in
LANL site response• Key issues/questions
• Can novel techniques be used to understand/confirm high-strain properties of softer tuff units (Qbt3L) and lateral variability of shallow units
• Can Hoodoo(s) be used to constrain design ground motion• Can a surface vibratory source be used to characterize deeper crustal
reflectors or generate refracted P- and SH-waves
Shaker Base PlateShaker Base Plate
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 21
Observa( ons+for+sta( on+#5+ Modeling+for+sta( on+#5+
peaks&at&1.53Hz,&1.56Hz&and&1.88Hz& peaks&at&1.3Hz,&1.15Hz,&and&0.9Hz&
Topography and site effects from ambient noise
From Stolte, Cox, Stokoe and Lee (submitted)
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 22
3D numerical modeling
Basin Materials Geologic Groups and Associated Members
Elastic Properties and Associated Material Units
Vp (m/sec) Vs (m/sec)
QBT
Bandelier Group (Qb) Tshirege Members (Qbt) Cerro Toledo Interval (Qct) Otowi Members (Qbo)
Qbt* Qct, Qbo*
528 1558
Qbt3,4 Qbt2, Qbt1*, Qc*,Qb*
305 900
TB4 Flow body in Puye Cerros del Rio Basalts (Tb4)
Tb4 2288 Tb4 1321
TPF
Puye Fanglomerate (Tpf) Pumaceous (Tpp) Tschicoma (Tt)
Tp*, Tt* 2288 Tp*, Tt* 1321
TPT Gravel Puye Totavi (Tpt)
Tpt 2288 Tpt 1321
TK Flow body in Santa Fe Keres Basalt (Tk)
Tk 2797 Tk 1615
TF Santa Fe Group Fanglomerate (Tf)
Tf 2797 Tf 1615
TSF Santa Fe Silt and Sands Tertiary (Ts) Galisteo (Tgs)
Ts, Tgs 2797 Ts, Tgs 1615
PAL Older Sedimentary Pal 2797 Pal 1615
PcF Pre Cambrian Flow Pc Flow 5993 Pc Flow 3460 Pc Pre Cambrian Pc 5993 Pc 3460
Based on the Spectral Element Method:• Finite element – hexahedra• Spectral convergence• Full wave 3D modeling (Chaljub, GJI, 2015)
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 23
Preliminary results Site Effects
Predicted resonance peak:f0=vs/4H=2.24Hz
Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA
Questions?
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 25
LANL Strategy Seismic Safety (summary)
• Seismic Hazard Program – Follow accepted guidance for seismic characterization, model development, incorporation of uncertainties, peer review, and documentation
• Engineering Standards Program – Manual for compliance with standards and orders
• Engineering Evaluation – Design new facilities to mitigate the effects of seismic hazard, evaluate existing facilities to understand impact of the seismic hazard
Seismic Hazard
Program
Engineering Evaluations
Engineering Standards Program
Los Alamos National Laboratory
2016 Natural Hazard Phenomena conference: 10/19/2016 26
Magnitude and Distance Contributions to the Mean
Peak Horizontal Acceleration Hazard at
10,000-Year Return Period at CMRR (Stochastic).
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