1) Free from earthquakes 
Not associated with an earthquake, as in aseismic slip. Also used to indicate an area with no record of earthquakes; an aseismic zone.
aseismic. This term describes a fault on which no earthquakes have been observed.
aseism, aseismic 1. Resistant to the destructive effects of earthquakes. 2. No earthquake; without shaking (as exists with an earthquake). Data on hydroseisms in wells are published annually by the U.S. Coast and Geodetic Survey. Fault slips include aseismic creep and transient slip Slip on faults occurs as a combination of relatively continuous...
free from earthquakes.