2/21/20132013 USGS NSHMP CA Workshop II1 UCERF3.2: Hazard Implications Hazard comparison metrics Inversion testing –Convergence and eqn. set weighting

2013 USGS NSHMP CA Workshop II 12/21/2013

UCERF3.2: Hazard Implications

• Hazard comparison metrics• Inversion testing

– Convergence and eqn. set weighting

• Hazard maps– Influence of logic tree branches– Contributions to changes in hazard

• Hazard curves at sites

2013 USGS NSHMP CA Workshop II 2

Hazard Evaluation: Metrics

• Ground motion values:– 2% in 50 years (Prob. Exceed.)– 10% in 50 years(Prob. Exceed.)– RTGM (1% Prob. Collapse in 50 yr.)

• Frequencies– PGA– 5Hz– 1Hz

• Curves: NEHRP (2009) Test Cities

Other WGCEP, PBR• Maps: Full logic-tree for PGA (1440 branches)

Partial tree for 1Hz (40 branches)

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Hazard Metrics: RTGM

• Risk Targeted Ground Motion (RTGM)• Adopted by BSSC in conjunction with 2009 NEHRP

provisions• Ground motion for 1% probability of collapse in 50

years• Computed at frequencies: 5Hz and 1Hz• Scalar valued• Considers entire hazard curve

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Hazard Curves: Inversion Convergence

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San DiegoPGA

San Francisco1Hz

• Examine variation over repeated inversion runs• Single “reference” branch• 100 runs


Hazard Curves: Inversion Eqn. Weights

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San DiegoPGA

San Francisco1Hz

• Examine effect of varying inversion equation weights• 11 weight variants


Hazard Maps: UC2 vs. UC3

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Hazard Ratios: Grid vs. Fault Sources

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Hazard Ratios: Grid Source Comparison

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Hazard Ratios: Smooth Seis. Comparison

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Branch Ratios: Fault Models

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Branch Ratios: Deformation Models

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Branch Ratios: Magnitude Scaling Rel.

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Branch Ratios: Dsr (slip along rupture)

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Branch Ratios: M≥5 rate

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Branch Ratios: Off-fault Mmax

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Branch Ratios: Smoothed Seis. models

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Hazard Ratio: Sources of Change

• Explain all non-yellow areas– Smoothed seismicity

model– New faults, slip changes,

or Mo rate changes– Methodological changes

Shows influence of Mmax & total M≥5 rate increase for gridded seismicity

UCERF 3.2 / NSHMP08 Grid Sources Only(and using only U2 Smoothed Seis.)

Sources of Change: Mmax & M≥5 rate

Shows influence of tighter U3 Smoothed Seis. Model

UCERF 3.2 / NSHMP08 Grid Sources Only(using both U2 & U3 Smoothed Seis.)

Artifact of “Deep seismicity” being excluded from denominator map

Sources of Change: Artifacts

UCERF 3.2 / NSHMP08 Grid Sources Only(using both U2 & U3 Smoothed Seis Map)

Influenced by UCERF3 smoothed- seismicity branch

Shows influence of tighter U3 Smoothed Seis. Model

Sources of Change: Grid Sources

UCERF3/UCERF2 Mo Rate

Big Lagoon-Bald Mtn:

Extended N ~60 km, and moment rate ~8 times higher on ABM

Log10(Mo ratio); new faults are black

Sources of Change: Fault Sources

New faults:Klamath Falls Lake E & W




Gillem and Cedar Mtn. faults have lower slip rates




Four new faults

Likely Fault (moment rate doubled)




8 new faults(ABM rates high due to block boundary)

Maacama (20% increase in moment rate)

West Napa (factor of 3.5 increase in Mo rate, ABM about 4 times higher than others)




Great Valley 07 (Orestimba) moment rate went down by ~60%

New Great Valley faults




Calaveras (So) - Paicines extension

Complex combination of new faults and geometric and rate changes




New fault:Oceanic – West Hausna(NeoKinema rate more than 4 times higher than others)

3 new faults




New fault: Lost Hills

Mix of new faults & gridded sources

New faults in Mojave




New Fault:Cerro Prieto

New faults: San ClementeSan Diego Trough Santa Cruz Catalina Ridge San Pedro Basin




Cucamonga: biggest methodological change

Death Valley Faults (North, South, and Black Mtn. Frontal): moment rates went down ~40%




Anacapa Dume: moment rate down by factor of 3




Addition of, or moment rate change on faults




Hazard Analysis Sites

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Hazard Analysis Sites

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Hazard Curves:

• Blue: Logic tree weighted mean hazard curve (UC3)

• Light Blue: Logic tree min max hazard curve range

• Red: UC2 logic tree weighted mean (solid), min and max (dashed) hazard curves

• Green: NSHMP reference value

• Ground motion histogram of logic tree branches summed over weights

• Tornado diagram

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Hazard Curves: Los Angeles

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PGA 1Hz


Hazard Curves: San Francisco

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PGA 1Hz


Sites with changes > 10%

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Site Group change

Redding WGCEP 287%

Brookings WGCEP 257%

San Diego NEHRP 137%

Carson City WGCEP 127%

Long Beach NEHRP 122%

Vallejo NEHRP 121%

Northridge NEHRP 119%

Big Sur WGCEP 118%

Century City NEHRP 114%

Site Group change

San Bernardino WGCEP 88%

Malibu West WGCEP 86%

Eureka NEHRP 86%

Palmdale WGCEP 85%

Santa Rosa NEHRP 83%

Oakland NEHRP 82%

Death Valley NEHRP 64%

Cucamonga WGCEP 59%


Hazard Curves: Redding (x3)

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PGA 1Hz


Grid & Fault Conributions: Redding

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Hazard Curves: San Diego (140%)

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PGA 1Hz


Hazard Curves: Vallejo (120%)

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PGA 1Hz


Hazard Curves: San Bernardino (88%)

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PGA 1Hz


Hazard Curves: Oakland (82%)

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PGA 1Hz


Hazard Curves: Cucamonga (50%)

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PGA 1Hz


Hazard Ratios: PGA vs. 1Hz

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Hazard Ratios: PGA vs. 1Hz

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Hazard Ratios: Logic-Tree Weight Variation

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Continued UCERF3 analysis…

• Branch averaged solutions• Deaggregation• Stacked histograms of ground motion distribution at

sites for each logic tree node (branch correlations)• Repeat convergence and equation weight tests• Higher resolution maps around San Francisco and

Los Angeles• Hazard analyses online:

– http://opensha.usc.edu/ftp/pmpowers/UCERF3.2/

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Documents

2/21/20132013 USGS NSHMP CA Workshop II1 UCERF3.2: Hazard Implications Hazard comparison metrics Inversion testing –Convergence and eqn. set weighting