Robert R. Youngs

We present a methodology for conducting a site-specific probabilistic analysis of fault displacement hazard. Two approaches are outlined.

Increasingly, fault slip rates are being used to constrain earthquake recurrence relationships for site-specific probabilistic seismic hazard (ground motion) assessments. This paper shows the sensitivity of seismic hazard assessments to variations in recurrence models and parameters that incorporate fault slip rates.

After more than a century of research, geologists and other scientists have increased their understanding of the tectonic processes at work in the Wasatch Front and are now beginning to answer the questions about the seismicity and tectonics of the Wasatch Front that Gilbert and others first posed Scientists, engineers, architects, urban planners, and emergency managers are not waiting for a major earthquake disaster to learn that measures must be implemented to mitigate an earthquake's effects.

We present a model for estimating horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The model provides predictive relationships for the orientation independent average horizontal component of ground motions. Relationships are provided for peak acceleration, peak velocity, and 5-percent damped pseudo-spectral acceleration for spectral periods of 0.01 to 10 seconds. The model represents an update of the relationships developed by Sadigh et al.

Comments from each of the six public hearings are available for viewing. Note that the public comment period is now closed.

Public Hearing Comments

Draft EIS

The draft EIS public comment period closed November 7, 2019. All 30,000+ comment submittals are now under review for consideration in the compilation of the final EIS.

Media & General Info

Point of Contact
John Scaggs
Tonto National Forest

Apache Leap Special Management Area
Apache Leap SMA website