Transcript WGCEP`s Recommendations for 2014 Maps

Oct 18th Discussion …
•
Decision time for NSHMP (& possible predicaments)
•
Suggested steps forward
•
Review logic tree options & evaluation criteria
Decision time for NSHMP
Present Situation Possibilities
Probability
1.
UCERF3 is reviewed in short order and everyone is
happy with methodology and results
10%
2.
UCERF3 is deemed technically flawed and not
fixable in time for 2014 NSHM.
20%
3.
Given complexity, there is not enough time for
adequate review & vetting of UCERF3 for NSHM
30%
50%
4.
UCERF3 is found to be technically sound (with
inevitable adjustments), but mean hazard changes
are up to factors of 10 in many areas (and only
understood to some level of specificity)
NSHMP options here?...
Decision time for NSHMP
NSHMP Options
if there is no UCERF3:
Issues:
a)
b)
c)
d)
Do not update CA ERF
2014
NSHMs
• for
What
exactly
is “UCERF2-like”?
• Who would do this (WGCEP is already near burnout &
Only update non fault-based
(with alternative regional rates and
wouldsources
be demoralized)?
spatial PDFs)
• This could take as long as fixing UCERF3
• Given La Quila, would anyone sign off on amodel that
Do (b) and add some of the new faults as type-B sources (bulge will increase)
using geologic slip rateslacks multi-fault ruptures?
Update everything including Type-A faults in a “UCERF2-like” way
Given:
Decision
time for NSHMP
1.
El Mayor-Cucapah (Mmax)
Darfield-Christchurch (Mmax & triggering)
Present Situation Possibilities
Probability
Tahoku (segmentation)
M8.6 Sumatra (“weird one”)
10%
UCERF3 is reviewed in short order and everyone is
happy with methodology
does anyone
and results
believe we know mean hazard within 10%?
2.
3.
20% we’ve
Are
we reluctant
to put
UCERF3 is deemed
technically
flawed
andthese
not out because it implies
user communities (or didn’t push the epistemic
fixable in time formisled
2014 NSHM.
uncertainties hard enough)?
30%
Given complexity,Isthere
is not
enoughimplications
time for
looking
at hazard
before finalizing weights
adequate review cheating?
& vetting of UCERF3 for NSHM
50%
4.
UCERF3 is found to be technically sound (with
inevitable adjustments), but mean hazard changes
are up to factors of 10 in many areas (and only
understood to some level of specificity)
Oct 18th Discussion …
•
Decision time for NSHMP (& possible predicaments)
•
Suggested steps forward
•
Review logic tree options & evaluation criteria
The WGCEP Path Forward
(the only one, in my opinion)
Wrap it up (finish and publish ASAP)
in part, to satisfy contractual obligation to CEA
Let others decide what to use in 2014 NSHMs
e.g., some weighted average of old and new hazard curves at each grid
node
The WGCEP Path Forward
(the only one, in my opinion)
Specific steps:
1)
2)
3)
4)
5)
6)
Get feedback here on final branches (& weights)
Decide how to handle convergence and equation set weights
Decide on any a posteriori weighting scheme (what to add to Morgan’s data-fits
table?)
Finalize calculations & document for review (by Nov 1st if all goes well?)
Activate review (hands on, aggressive, back and forth in terms of answering
questions); how long will this take? Finish by year end?
Finalize & publish in 2013
Oct 18th Discussion …
•
Decision time for NSHMP (& possible predicaments)
•
Suggested steps forward
•
Review logic tree options & evaluation criteria
Proposed Logic-Tree Branches:
Proposed Logic-Tree Branches:
Two Fault Models
• Same number as in UCERF2
• Weighted equally
Proposed Logic-Tree Branches:
Four Deformation Models
• Much broader range than in
UCERF2
• Off-fault moment rates provided
(UCERF2 Type-C zones gone!)
• A priori weights represent an
average among those of a special
review panel
Proposed Logic-Tree Branches:
Scaling Relationships
• Only HB08 & EllB used in UCERF2
• Equal a priori weights
Proposed Logic-Tree Branches:
Slip Along Rupture (Dsr)
• Added Boxcar option
• Equal a priori weights
Weldon et al. (2007)
Average of 13 large events
???
Characteristic Slip?
???
Proposed Logic-Tree Branches:
Total M≥5 Event Rate
• Per year, inside RELM region
• From Felzer (Appendix L)
• UCERF2 had single value of 7.5,
which is at the low end here (new
best estimate of 8.7 represents a
16% increase)
Proposed Logic-Tree Branches:
Inversion Model
(Fault-Section Nucleation MFD)
Characteristic UCERF2 Constrained:
1/3 GR and 2/3 Char
UCERF2 type
MFD
* if Type-A in UCERF2, use UCERF2 nucleation
MFD instead.
Gutenberg-Richter Constrained:
b=1
Proposed Logic-Tree Branches:
Inversion Model
(Fault-Section Nucleation MFD)
???
Use only
Characteristic
???
???
If Gutenberg-Richter
requires reducing slip rates
by ~40%, how many would
give it a relative weight >
10%?
???
Proposed Logic-Tree Branches:
Mmax Off Fault
• UCERF2 had “off-fault” values of either
7.0 or 7.6
• El Mayor-Cucapah exceeded 7.0; so
we’ve increased to 7.2 at the low end
• The value of 8.0 is new
• Weights are different for Char vs GR
branches
UCERF2 Mmax
Proposed Logic-Tree Branches:
Off-Fault Spatial Seis PDF
• Three options, with two new ones:


UCERF3 Smoothed Seis
Deformation Model Ave
• 3 more could be added (1 for each
deformation model)
• Weights are different for Char vs GR
branches
• Exactly how these are used shortly…
Proposed Logic-Tree Branches:
Log10(Prob) for Each Grid Cell
(values sum to 1.0)
Off-Fault Spatial Seis PDF
UCERF2
Smoothed
Seismicity
???
Use
deformationmodel-specific
off-fault
spatial PDFs
???
ABM
UCERF3
Smoothed
Seismicity
NeoKinema
Average
Deformation
Model
Zeng
Proposed Logic-Tree Branches:
Fault Moment-Rate Fixes
• This deals with cases where fault
moment rates are too high to
satisfy all data
• Currently only an issues for GR
branches?
• More on this shortly
Grand Inversion Results
Evaluation Metrics:
Data Fits:
- Regional MFDs
- Slip-rate fits
- Paleo event-rate & ave-slip fits
- Tabulation of equation-set fits and
other metrics (e.g., implied CC)
Implications Plots:
- Participation rate maps
- Parent-section MFDs (also tabulated)
- Correlation between paleo sites
- Implied segmentation (e.g., on SAF)
- Fault-jumping statistics
- Slip COVs (e.g., Hecker et al.)
- Lots of stuff in SCEC VDO
ERF-Based Plots:
- MFDs in LA and SF Boxes
- Hazard curves at sites
- Hazard Maps
- RTGM at sites
- Statewide Losses
We currently
have these
(and more)
implemented
, although we
haven’t yet
had time to
examine
everything
Mean, Min,
and Max from
all logic-tree
branches
UCERF3 Mean
UCERF3 Mean
Cumulative
UCERF2