Development of Thailand National Seismic Development of Thailand National Seismic Hazard MapsHazard Maps

Mark D. Petersen, Steve Harmsen, Kathy Haller, Mark D. Petersen, Steve Harmsen, Kathy Haller, Nicolas Nicolas LucoLuco, Charles Mueller (URS) , Charles Mueller (URS)

Maps for ThailandMaps for Thailand

2% probability of exceedance in 50 years2% probability of exceedance in 50 years760 760 m/sm/s VsVs--30 (firm rock site conditions)30 (firm rock site conditions)StrawmanStrawman inputs (e.g., Need better rates on inputs (e.g., Need better rates on subduction zone, faults, etc.)subduction zone, faults, etc.)Sources considered (shallow seismicity, deep Sources considered (shallow seismicity, deep seismicity, Sumatra fault, faults near Thailand, seismicity, Sumatra fault, faults near Thailand, subduction zone)subduction zone)

Shallow gridded seismicity

Shallow Gridded Seismicity

Deep Gridded Seismicity

Deep Gridded Seismicity

Subduction zone

Subduction zone (with Gregor)

Sumatra Fault

Faults near Thailand (High Q)

Thailand faults (High Q)

Thailand Faults (High Q- GR)

Thailand Faults (High Q-500 km distance cutoff)

Thailand Faults (Low Q)

Thailand Faults (Low Q)

Thailand Faults (High Q)

Hazard Map (all sources)

Hazard Map (All sources)

ConclusionsConclusions

Three Pagoda fault important for central Three Pagoda fault important for central ThailandThailandShallow seismicity and faults important for Shallow seismicity and faults important for northern Thailandnorthern ThailandSignificant Difference between attenuation Significant Difference between attenuation relations (Need to know Q, stress drop, etc.)relations (Need to know Q, stress drop, etc.)