C.M. DePolo
J. C. Yount
A. R. Ramelli
2003
<p><span>The </span>1994<span> </span>Double<span> </span>Spring<span> </span>Flat<span> </span>earthquake<span> (M</span><sub>w</sub><span> 5.8) occurred within a densely faulted step-over between the Genoa and Antelope Valley faults, two principal normal faults of the transition zone between the Basin and Range Province and the northern Sierra </span>Nevada<span>. The </span>earthquake<span> created zones of </span>ground<span> </span>cracks<span> from 0.1 to 2.8 km long along at least five northwest- to north-northwest-striking faults in the epicentral area. Individual </span>cracks<span> had extensional openings generally from 1 to 10 mm wide. No </span>cracks<span> displayed obvious vertical separation, and only one zone showed permissive evidence of right-lateral separation. Over the 8 days following the mainshock (the period over which the </span>cracks<span> were found), aftershocks formed a dominant northeast trend suggesting the </span>earthquake<span> occurred along a northeast-striking structure. However, no </span>ground<span> breakage was found along faults striking parallel to this northeast aftershock alignment, and subsequent aftershocks formed a conjugate northwest trend. Based on the location and character of the five zones, the observed </span>cracks<span> are attributed to secondary fault slip and shaking effects. The </span>earthquake<span> also created </span>ground<span> </span>cracks<span> along at least two faults 15-25 km from the epicenter. In both of these cases, the faults had documented histories of prior </span>ground<span> cracking, indicating that they are particularly susceptible to such triggered deformation.</span></p>
application/pdf
10.1785/0120020177
en
Seismological Society of America
Ground cracks associated with the 1994 double spring flat earthquake, west-central Nevada
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