Ivan Wong

Lithostatic stresses and their redistribution around mine excavations are thought to be the dominant driving force in the generation of most mine tremors and rockbursts.

This report presents the results of a site- specific probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA) for the Near West site in southern Arizona.

A probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA) were performed for Resolution Copper’s Mine site including the area above the deposit (Mine area) and the area covering the East Plant site (Shafts 9/10).

The contemporary seismicity of the Colorado Plateau based on seismic monitoring in the past 30 yr can be characterized as being of small to moderate magnitude, and contrary to earlier views, of a low to moderate rate of occurrence with earthquakes widely distributed.

Lake Roberts Dam is located in Grant County in southwestern New Mexico. Tectonically the damsite is within the Southern Basin and Range Province and the Rio Grande rift as defined by Machette (1998). Although the historical seismicity in the region has been low, the site has undoubtedly been shaken by past large prehistoric earthquakes caused by active regional faults and in historical times, as recently as 1887 (Figures 2 to 4).

Probabilistic seismic hazard analysis (PSHA) has become a fundamental tool is assessing seismic hazards and for estimating seismic design and seismic safety evaluation of ground motions. It is used on a site-specific basis for important and critical facilities and on a national scale for building codes. This report describes a project to test and verify the numerical approaches and software used in PSHA.

At the request of Resolution Mining Company (RMC), this report presents the results of sitespecific probabilistic seismic hazard analyses (PSHA) and deterministic seismic hazard analyses (DSHA) of four sites for the RMC tailings storage facilities options in southern Arizona.

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
john.scaggs@usda.gov

Apache Leap Special Management Area
Apache Leap SMA website