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Homestake Mining Company May 10,2019 <br /> Regular(112d)Operation Reclamation Permit Application Package <br /> Arkansas Valley (USGS, 2018). The faults are at distances of approximately 25 km and 20 km <br /> from the Mine, respectively. <br /> Historic seismicity within the SRM region is sparse and occurs at relatively low-rates (Figure 3-5). <br /> The nearest Magnitude (M) 3 earthquake was located approximately 25 mi to the east-northeast. <br /> The largest earthquake within the region was an M 4.28 which occurred in 1966, approximately <br /> 40 miles to the north. <br /> Earthquake ground motions at the Mine were originally estimated as part of the Robertson- <br /> Pincock, Inc. report titled Waste Dump Stability Evaluation (RP, 1979). Their estimated maximum <br /> ground motion acceleration for a 100-year return period at the site is 0.03 gravity(g). This estimate <br /> is based on the Gumble (1958) methodology which used historical seismicity and did not include <br /> regional fault sources. More recent ground motion estimates from the U.S. Geological Survey <br /> (USGS)are based on an updated earthquake catalog and fault sources. Ground motions estimate <br /> produced using the USGS online Unified Hazard Tool" yield an estimated peak ground <br /> acceleration (PGA) of 0.16g at the site for the 1:2475 Annual Exceedance Probability (AEP) <br /> (2% in 50 Years). Using this tool the estimated PGA for a 1:100 AEP is 0.018g. <br /> " The USGS Unified Hazard Tool can be accessed at the following address: <br /> https://earthquake.usgs.gov/hazards/interactive/ <br /> EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 18 <br /> HOMESTAKE MINING COMPANY <br />