64 research outputs found

    Borehole tensor strain measurements in California ( USA)

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    Two continuous borehole plane strain monitoring sites have been operational in California since late 1983, using borehole tensor strain monitors implanted at a depth of 150 m. Shear strain data at subtidal sensitivies were available immediately after installation without contamination by bond curing or thermal recovery signals. At Pinon Flat Observatory, data indicate a constant shear strain accumulation of 0.6 microstrain per annum with the axis of maximum compression oriented 50o + or - 5o W of N. This result differs significantly from regional geodetic estimates, the amplitude being dominated by continued visoelastic response of the hole. Preliminary analysis of strain steps observed at San Juan Bautista during the Morgan Hill earthquake of April 24, 1984 show good agreement with calculations from seismically determined source parameters for this event. -from Author

    Earthquake scaling relations for mid-ocean ridge transform faults

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    Author 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.A 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.M.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

    Sustainability-oriented innovation: a systematic review

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    types: ArticlePre-print draft of article submitted to International Journal of Management ReviewsIn this article we systematically review the literature relating to Sustainability-Oriented Innovation (SOI), and present a model to help understand different types and phases of SOI in companies. SOI involves making intentional changes to organizational mind-sets and values, as well as the products, processes or practices that produce environmental and/or social benefits in addition to economic value. The model distinguishes between contexts of Operational Optimization, Organizational Transformation, and Systems Building, and is populated with a range of innovation practices illustrating what firms do to become more sustainable. The model is developed from a review of 127 articles from the academic and practitioner literature and focuses on the period between the two Earth Summits (1992-2012). The systematic review forms the foundation of this paper, but we supplement and populate the model with instances of SOI activity drawn from more recent practitioner literature to provide richer insights into contemporary pioneering SOI practice."This is the peer reviewed version of the following article: Sustainability-oriented Innovation: A Systematic Review, International Journal of Management Reviews, 2015, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/ijmr.12068/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

    The Epidemiology, Genetics and Future Management of Syndactyly

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    Syndactyly is a condition well documented in current literature due to it being the most common congenital hand defect, with a large aesthetic and functional significance
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