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dc.contributor.authorBoettcher, Margaret S.
dc.contributor.authorJordan, T. H.
dc.date.accessioned2010-05-24T18:29:15Z
dc.date.available2010-05-24T18:29:15Z
dc.date.issued2004-12-09
dc.identifier.citationJournal of Geophysical Research 109 (2004): B12302en_US
dc.identifier.urihttp://hdl.handle.net/1912/3501
dc.descriptionAuthor Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 109 (2004): B12302, doi:10.1029/2004JB003110.en_US
dc.description.abstractA mid-ocean ridge transform fault (RTF) of length L, slip rate V, and moment release rate dot above M can be characterized by a seismic coupling coefficient χ = A E/A T, where A E ∼ dot above M/V is an effective seismic area and A T ∝ L 3/2 V −1/2 is the area above an isotherm T ref. A global set of 65 RTFs with a combined length of 16,410 km is well described by a linear scaling relation (1) A E ∝ A T, which yields χ = 0.15 ± 0.05 for T ref = 600°C. Therefore about 85% of the slip above the 600°C isotherm must be accommodated by subseismic mechanisms, and this slip partitioning does not depend systematically on either V or L. RTF seismicity can be fit by a truncated Gutenberg-Richter distribution with a slope β = 2/3 in which the cumulative number of events N 0 and the upper cutoff moment M C = μD C A C depend on A T. Data for the largest events are consistent with a self-similar slip scaling, D C ∝ A C 1/2, and a square root areal scaling (2) A C ∝ A T 1/2. If relations 1 and 2 apply, then moment balance requires that the dimensionless seismic productivity, ν0 ∝ inline equation 0/A T V, should scale as ν0 ∝ A T −1/4, which we confirm using small events. Hence the frequencies of both small and large earthquakes adjust with A T to maintain constant coupling. RTF scaling relations appear to violate the single-mode hypothesis, which states that a fault patch is either fully seismic or fully aseismic and thus implies A C ≤ A E. The heterogeneities in the stress distribution and fault structure responsible for relation 2 may arise from a thermally regulated, dynamic balance between the growth and coalescence of fault segments within a rapidly evolving fault zone.en_US
dc.description.sponsorshipM.B. was supported by a NSF Graduate Research Fellowship, a MIT Presidential Fellowship, and the WHOI DOEI Fellowship. This research was supported by the Southern California Earthquake Center. SCEC is funded by NSF Cooperative Agreement EAR-0106924 and USGS Cooperative Agreement 02HQAG0008.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2004JB003110
dc.subjectEarthquakesen_US
dc.subjectScaling relationsen_US
dc.subjectFault mechanicsen_US
dc.titleEarthquake scaling relations for mid-ocean ridge transform faultsen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2004JB003110


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