1. Earthquake Hazard Class Mapping by Parcel in Las Vegas Valley John N. Louie Nevada Seismological Laboratory Satish K. Pullammanappallil Aasha Pancha, Travis West Optim Seismic Data Solutions Werner K. Hellmer Clark County Dept. of Development Services J. Louie et al., Structures Congress 4/14/2011

2. Parcel Map Enables “Next-Level ShakeZoning”  Goal is to predict earthquake shaking For hazard mapping, planning For hazard mapping, planning Building-code development and enforcement Building-code development and enforcement Provide time histories of shaking to designers Provide time histories of shaking to designers  USGS ShakeMap Based on statistical averages; sparse data Based on statistical averages; sparse data Most data came from California, Japan, Taiwan Most data came from California, Japan, Taiwan  Next-Level ShakeZoning for Nevada Based on: Wave Physics Based on: Wave Physics Geological & Geotech data: Parcel Map unsurpassed Geological & Geotech data: Parcel Map unsurpassed Validating against Nevada earthquake records Validating against Nevada earthquake records J. Louie et al., Structures Congress 4/14/2011

3. Clark County & Henderson Parcel Map 10,721 Measurements Urban Areas of County J. Louie et al., Structures Congress 4/14/2011

4. Parcel Mapping Surface-Wave Arrays Every One Hand-Modeled J. Louie et al., Structures Congress 4/14/2011

5. Blind Tests of Parcel Map  Different: Equipment Field crew Dispersion interpreter Vs(z) modeler  Match to Map Values: 6 of 93 blind tests >10% off 13.55% max diff. 0.26% bias of average 4.92% RMS difference J. Louie et al., Structures Congress 4/14/2011

6. Clark County & Henderson Parcel Map Parcel Classification for IBC NEHRP C & D classes “C+” class for NEHRP B velocities with soft surface J. Louie et al., Structures Congress 4/14/2011

7. Build Parcel Map into ShakeZoning Does it Make a Difference? ShakeZoning Geotech Map Warmer colors: lower Vs30 (meter) Parcel Map on top of IBC default Vs30 J. Louie et al., Structures Congress 4/14/2011

8. Adding Fault and Basin Geology Black Hills Fault in Google Earth with USGS Qfaults trace USGS Basin Map J. Louie et al., Structures Congress 4/14/2011

9. Adding Physics  Black Hills M6.5 event Short trace but 4-m scarps noted Short trace but 4-m scarps noted  Viscoelastic finite- difference solution 0.5-Hz frequency 0.5-Hz frequency 0.20-km grid spacing 0.20-km grid spacing A few hours on our small cluster A few hours on our small cluster  Mode conversion, rupture directivity, reverberation, trapping in basins J. Louie et al., Structures Congress 4/14/2011

10. Black Hills M6.5 Scenario Results  Max Peak Ground Velocity (PGV) >140 cm/sec  PGV over 60 cm/sec (yellow) bleeds into LVV through Railroad Pass  Large event for a short fault Unlikely, but add to hazard probabilistically Unlikely, but add to hazard probabilistically  Need to know how unlikely J. Louie et al., Structures Congress 4/14/2011

11. Surprising Effect of Parcel Map Over IBC Defaults 1-D Amplification Used in IBC, ShakeMap 3-D Amplification from ShakeZoning J. Louie, NESC 2/9/2011

12. ShakeMap versus ShakeZoning Yellow is 60 cm/sec on both Yellow is 60 cm/sec on both Geotech estimated from topography Geotech estimated from topography ShakeZoning shows trapping in basins ShakeZoning shows trapping in basins Hazard map is difficult to predict Hazard map is difficult to predict J. Louie, NESC 2/9/2011

13. Frenchman Mountain Fault M6.7 Scenario Possible Scarp in Neighborhood Event Inside the LVV Basin J. Louie, NESC 2/9/2011

14. 2-Segment Frenchman Mtn. Fault M6.7 J. Louie, NESC 2/9/2011

15. Effect of Parcel Map Over IBC Defaults

16. With Many Scenarios, Define Probabilistic Hazard  Recurrence Intervals: Black Hills- 15 ka Black Hills- 15 ka Frenchman Mtn.- 45 ka Frenchman Mtn.- 45 ka  e.g., PGV at UNLV: ~20 cm/s from BHF ~20 cm/s from BHF ~15 cm/s from FMF ~15 cm/s from FMF  Combine rates per annum: >15 cm/s at 0.0001 p.a. >15 cm/s at 0.0001 p.a. >20 cm/s at 0.00007 p.a. >20 cm/s at 0.00007 p.a. J. Louie et al., Structures Congress 4/14/2011

17. With Many Scenarios, Define Probabilistic Hazard J. Louie, EGGE 3/25/2011  Japan and New Zealand Lesson: Don’t Ignore Worst Case! dePolo, 2008, NBMG Map 167