| Abstract: | The high-frequency falloff ??-y of earthquake displacement spectra and the b value of aftershock sequences are attributed to the character of spatially varying strength along fault zones. I assume that the high frequency energy of a main shock is produced by a self-similar distribution of subevents, where the number of subevents with radii greater than R is proportional to R-D, D being the fractal dimension. In the model, an earthquake is composed of a hierarchical set of smaller earthquakes. The static stress drop is parameterized to be proportional to R??, and strength is assumed to be proportional to static stress drop. I find that a distribution of subevents with D = 2 and stress drop independent of seismic moment (?? = 0) produces a main shock with an ??-2 falloff, if the subevent areas fill the rupture area of the main shock. By equating subevents to "islands‘ of high stress of a random, self-similar stress field on a fault, I relate D to the scaling of strength on a fault, such that D = 2 - ??. Thus D = 2 corresponds to constant stress drop scaling (?? = 0) and scale-invariant fault strength. A self-similar model of aftershock rupture zones on a fault is used to determine the relationship between the b value, the size distribution of aftershock rupture zones, and the scaling of strength on a fault. -from Author |
| Genre: | Article |
| ProdID: | 70016902 |
| Citation Author: | Frankel, A. |
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| Citation End Page: | 6302 |
| Citation Issue: | B4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Geophysical Research |
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| Citation Number Of Pages: | 12 |
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| Citation Search Results Text: | High-frequency spectral falloff of earthquakes, fractal dimension of complex rupture, b value, and the scaling of strength on faults; 1991; Article; Journal; Journal of Geophysical Research; Frankel, A. |
| Citation Start Page: | 6291 |
| Citation Volume: | 96 |
| Citation Year: | 1991 |
| Type: | citation/reference |
| Text: | High-frequency spectral falloff of earthquakes, fractal dimension of complex rupture, b value, and the scaling of strength on faults; 1991; Article; Journal; Journal of Geophysical Research; Frankel, A. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1991 00:00 -0600 |
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