Shear Zones in Eastern California and Western Nevada.

We added areal shear zones along the western border of Nevada extending from the northern end of the Death Valley fault through the Tahoe-Reno area through northeast California ending at the latitude of Klamath Falls, Oregon (see Figure 26). We assigned a shear rate of 4 mm/yr to zone 1, and 2 mm/yr to zones 2 and 3. The shear rate in zone 1 is comparable to the shear rate observed on the Death Valley fault, but which is not observed in mapped faults north of the Death Valley fault (C. dePolo and J. Anderson, pers. comm., 1996). For the Foothills Fault system (zone 4) we used a shear rate of 0.05 mm/yr. a-values were determined for these zones in the manner described in Ward(1994). For zones 1-3, we used a magnitude range of 6.5-7.3. For zone 4, we used a magnitude range of 6.0-7.0. The maximum magnitude for the calculation of hazard from the smoothed historic seismicity was lowered in these zones so that it did not overlap with these magnitude ranges. Fictitious faults with a fixed strike were used in the hazard calculation for these zones. Again, use of these areal zones in California was agreed upon after consultation with CDMG personnel.