... (∼10 4 years). Figure 3. ▴ Example of the overturning probability of a regular-shaped precarious object with α = 0.29 radians and p 2 = mgR/I = 11.5 s –2 , from Purvance, Anooshehpoor et al. (2008). The slenderness α is defined in Figure 1 , m is the mass of the rock, g...

...John G. Anderson; James N. Brune Abstract Fields of precariously balanced rocks indicate that strong earthquake motions have not occurred at that site since the precarious rocks developed. These fields can be characterized with an estimate of the peak acceleration that would be sufficient to topple...

...James N. Brune © 1999 by the Seismological Society of America 1999 It has been suggested that groups of precariously balanced rocks are effectively earthquake strong ground-motion seismoscopes that have been operating on solid rock outcrops for thousands of years, thus providing...

...James N. Brune Abstract Preliminary interpretations of precarious rock observations suggest relatively low near-fault (<3 km) footwall ground motions for normal faults relative to strike-slip faults, as reported for a dynamic foam rubber normal fault model by Brune and Anooshehpoor ( 1999...

... and the presence of precariously balanced rocks on the footwall of two thrust faults in Southern California indicate relatively low ground motions, thus indicating strong asymmetry in ground motions near the fault trace for thrust faults. Some current ground-motion attenuation curves and hazard maps may give too...

... and the presence of precariously balanced rocks on the footwall of two thrust faults in Southern California indicate relatively low ground motions, thus indicating strong asymmetry in ground motions near the fault trace for thrust faults. Some current ground-motion attenuation curves and hazard maps may give too...

...James N. Brune Abstract New examples of precarious rocks are presented. These rocks provide constraints on ground motion for historical and recent large earthquakes. An approximate field calibration of the precarious-rock methodology was provided by the M 7.1 Hector Mine earthquake of 16 October...