eprintid: 1440 rev_number: 16 eprint_status: archive userid: 2 dir: disk0/00/00/14/40 datestamp: 2015-02-10 14:32:53 lastmod: 2017-02-08 12:21:44 status_changed: 2015-04-27 12:10:54 type: article metadata_visibility: show creators_name: Wyss, Max creators_name: Sammis, Charles creators_name: Nadeau, Robert creators_name: Wiemer, Stefan creators_id: wapmerr@maxwyss.com creators_id: sammis@usc.edu creators_id: nadeau@seismo.berkeley.edu creators_id: stefan.wiemer@sed.ethz.ch corp_creators: World Agency of Planetary Monitoring and Earthquake Risk Reduction Route de Malagnou 36A CH-1208 Geneva, Switzerland corp_creators: (M.W.) University of Southern California Los Angeles, California 90007 corp_creators: (C.G.S.) Berkeley Seismological Laboratory and Center for Computational Seismology Lawrence Berkeley National Laboratory University of California Berkeley, California 94720 corp_creators: (R.M.N.) Institute of Geophysics ETH Hoenggerberg CH-8093, Zurich, Switzerland title: Fractal Dimension and b-Value on Creeping and Locked Patches of the San Andreas Fault near Parkfield, California ispublished: pub subjects: MP2_2 divisions: EPOS-P full_text_status: none abstract: We tested the hypotheses (1) that the fractal dimension, D, of hypocenters are different in a locked and a creeping segment of the San Andreas fault and (2) that the relationship D~`2b holds approximately, where b is the slope of the frequency–magnitude relationship. The test area was the 30- to 50-km fault segment north of Parkfield for which two earthquake catalogs exist: the borehole High Resolution Seismic Network data, and the U.S. Geological Survey data, which have a minimum magnitude of completeness of Mc 0.4 and Mc 1.0–1.2, respectively. The relative location errors in the two catalogs are estimated as 0.25 km and less than 1 km, respectively. The periods of high-quality data available extend from 1987 to 1998.5 and 1981 to 2000.2, respectively, furnishing 2609 and 3775 events for analysis, in the two catalogs. In the locked part, 0.5 < b < 0.7 and 0.96 < D < 1.14, whereas in the creeping segment, 1.1 < b < 1.6 and 1.45 < D < 1.72. However, the spatial distribution of the hypocenters in the creeping segment is not well approximated by a fractal distribution. We conclude (1) that the frequency–magnitude distribution as described by b, as well as the fractal dimension (D), are different in the locked and creeping segments near Parkfield; (2) that the spatial distribution in the creeping segment is not well approximated by a fractal distribution; and (3) that the relationship D~2b holds in the locked segment, where both parameters can be measured accurately. Thus, we propose that the heterogeneity of seismogenic volumes lead to differences in D and b and that these differences, where established by high-quality data, may furnish clues concerning properties of fault zones. date: 2004-04 date_type: published publication: Bulletin of the Seismological Society of America volume: 94 number: 2 publisher: Seismological Society of America pagerange: 410-421 id_number: doi:10.1785/0120030054 refereed: TRUE issn: 0037-1106 official_url: http://dx.doi.org/10.1785/0120030054 access_IS-EPOS: limited owner: Publisher citation: Wyss, Max and Sammis, Charles and Nadeau, Robert and Wiemer, Stefan (2004) Fractal Dimension and b-Value on Creeping and Locked Patches of the San Andreas Fault near Parkfield, California. Bulletin of the Seismological Society of America, 94 (2). pp. 410-421. DOI: https://doi.org/10.1785/0120030054