Next-Level ShakeZoning for Earthquake Hazard Definition

in NevadaJohn N. Louie, Nevada Seismological Lab.

with undergraduate interns:Will Savran, Brady Flinchum, Colton Dudley, Nick Prina

and Geology B.S. graduate Janice Kukuk

USGS ShakeMap based on statistical averages Most data came from California, Japan, Taiwan

Next-Level ShakeZoning for Nevada Based on Physics, Geological & Geotechnical data

J. Louie, NESC 2/9/2011

Clark County & Henderson Parcel Map10,721 Measurements Parcel Classification for IBC

J. Louie, NESC 2/9/2011

Adding Geology & Geotechnical DataBlack Hills Fault in Google Earth with USGS Qfaults trace

ShakeZoning Geotech Map

J. Louie, NESC 2/9/2011

Adding Physics

Black Hills M6.5 event Short trace but 4-m scarps

noted Viscoelastic finite-

difference solution 0.5-Hz frequency 0.20-km grid spacing A few hours on our small

cluster Mode conversion, rupture

directivity, reverberation, trapping in basins

J. Louie, NESC 2/9/2011

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 Need to know how unlikely

J. Louie, NESC 2/9/2011

Surprising Effect of Parcel Map Over IBC Defaults1-D Amplification Used in IBC, ShakeMap

3-D Amplification from ShakeZoning

J. Louie, NESC 2/9/2011

ShakeMap versus ShakeZoning•Yellow is 60 cm/sec on both•Geotech estimated from topography

•ShakeZoning shows trapping in basins•Hazard map is difficult to predict

J. Louie, NESC 2/9/2011

Frenchman Mountain Fault M6.7 ScenarioPossible Scarp in Neighborhood

Event Inside the LVV Basin

J. Louie, NESC 2/9/2011

2-Segment Frenchman Mtn. Fault M6.7

J. Louie, NESC 2/9/2011

Effect of Parcel Map Over IBC Defaults

J. Louie, NESC 2/9/2011

We Are Computing Dozens of Scenarios

J. Louie, NESC 2/9/2011