Earthquake Hazard Maps Probabilistic Earthquake Hazard Maps for the State of Montana Historical Seismicity Quat Faults Regional Source Zones (a) Quaternary Faults in Southhwestern Montana (b) Quaternary Faults in Northwestern Montana Distribution of Quaternary Basins and Site Response Units Depth to Tertiary Rock in Montana Peak Horizontal Acceleration on Rock 500 yr Return Period 0.2 Sec Horizontal Acceleration on Rock 500 yr Return Period 1 Sec Horizontal Acceleration on Rock 500 yr Return Period Peak Horizontal Acceleration on Rock 2500 yr Return Period 0.2 Sec Horizontal Acceleration on Rock 2500 yr Return Period 1 Sec Horizontal Acceleration on Rock 2500 yr Return Period Peak Horizontal Acceleration on Rock 5000 yr Return Period 0.2 Sec Horizontal Acceleration on Rock 5000 yr Return Period 1 Sec Horizontal Acceleration on Rock 5000 yr Return Period Peak Horizontal Acceleration on Surface 500 yr Return Period 0.2 Sec Horizontal Acceleration on Surface 500 yr Return Period 1 Sec Horizontal Acceleration on Surface 500 yr Return Period Peak Horizontal Acceleration on Surface 2500 yr Return Period 0.2 Sec Horizontal Acceleration on Surface 2500 yr Return Period 1 Sec Horizontal Acceleration on Surface 2500 yr Retrurn Period Peak Horizontal Acceleration on Surface 5000 yr Return Period 0.2 Sec Horizontal Acceleration on Surface 5000 yr Return Period 1 Sec Horizontal Acceleration on Surface 5000 yr Return Period Modal Magnitude for Peak Horizontal Acceleration on Rock 500 yr Return Period Modal Magnitude for Peak Horizontal Acceleration on Rock 2500 yr Return Period Modal Magnitude for Peak Horizontal Acceleration on Rock 5000 yr Return Period Modal Distance for Peak Horizontal Acceleration on Rock 500 yr Return Period Modal Distance for Peak Horizontal Accelertaion on Rock 2500 yr Return Period Modal Distance for Peak Horizontal Acceleration on Rock 5000 yr Return Period
