86 research outputs found
Earthquake source properties from pseudotachylite
No full textEarthquake-radiated motions contain in formation that can be interpreted as source displacement and therefore related to stress drop. Except in a few notable cases, these displacements cannot be easily related to the absolute stress level, the fault strength, or attributed to a particular physical mechanism. In contrast paleo-earthquakes recorded by exhumed pseudotachylite have a known dynamic mechanism whose properties constrain the co-seismic fault strength. Pseudotachylite can be used to directly address a discrepancy between seismologically-measured stress drops, which are typically a few MPa, and much larger dynamic stress drops expected from thermal weakening during slip at seismic speeds in crystalline rock [Sibson, 1973; McKenzie and Brune, 1969; Lachenbruch, 1980; Mase and Smith, 1986; Rice, 2006] as have been observed in laboratory experiments at high slip rates [Di Toro et al., 2006a]. This note places pseudotachylite-derived estimates of fault strength and inferred crustal stress within the context and bounds of naturally observed earthquake source parameters: apparent stress, stress drop, and overshoot, including consideration of fault surface roughness, off-fault damage, fracture energy, and the 'strength excess'. The analysis, which assumes stress drop is related to corner frequency by the Madariaga [1976] source model, is restricted to earthquakes of the Gole Larghe fault zone in the Italian Alps where the dynamic shear strength is well21constrained by field and laboratory measurements. We find that radiated energy is similar to or exceeds the shear-generated heat and that the maximum strength excess is ~16 MPa. These events have inferred earthquake source parameters that are rare, for instance a few percent of the global earthquake population has stress drops as large, unless: fracture energy is routinely greater than in existing models, pseudotachylite is not representative of the shear strength during the earthquake that generated it, or unless the strength excess is larger than we have allowed
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Does fault strengthening in laboratory rock friction experiments really depend primarily upon time and not slip?
No full textThe popular constitutive formulations of rate‐and‐state friction offer two end‐member views on whether friction evolves only with slip (Slip law) or with time even without slip (Aging law). While rate stepping experiments show support for the Slip law, laboratory‐observed frictional behavior near zero slip rates has traditionally been inferred as supporting Aging law style time‐dependent healing, in particular, from the slide‐hold‐slide experiments of Beeler et al. (1994). Using a combination of new analytical results and explicit numerical (Bayesian) inversion, we show instead that the slide‐hold‐slide data of Beeler et al. (1994) favor slip‐dependent state evolution during holds. We show that, while the stiffness‐independent rate of growth of peak stress (following reslides) with hold duration is a property shared by both the Aging and (under a more restricted set of parameter combinations) Slip laws, the observed stiffness dependence of the rate of stress relaxation during long holds is incompatible with the Aging law with constant rate‐state parameters. The Slip law consistently fits the evolution of the stress minima at the end of the holds well, whether fitting jointly with peak stresses or otherwise. But neither the Aging nor Slip laws fit all the data well when a − b is constrained to values derived from prior velocity steps. We also attempted to fit the evolution of stress peaks and minima with the Kato‐Tullis hybrid law and the shear stress‐dependent Nagata law, both of which, even with the freedom of an extra parameter, generally reproduced the best Slip law fits to the data
Where the shadows lie: Nature, modernity and the audience of Middle-earth.
No full textThe following thesis examines the relevance of J. R. R. Tolkien's ' The Lord of the Rings' in relation to its audience and the social conditions of its completion and reception. This relevance is best described as an imaginary process by which the reader vicariously experiences a millenarian religious movement that attempts to reject modernity. The argument is divided into four main sections, each building upon the preceding concepts. The first is a discussion of audience and fan culture which uses semiotics as the basis by which readers understand the novel. The second examines the way in which the semiotic nature of the imaginary world of Middle-earth codifies the meaning of the text. Third, the relationship between the reader, author and modernity is defined. Finally, in the fourth chapter, the millennial process is defined in detail and its relationship to the reader and the text.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b128884
Nicholas Black. The British Naval Staff in the First World War. Woodbridge: Boydell Press, 2009. Pp. xiv+333. $115.00 (cloth).
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Now for the Contest: Coastal and Oceanic Naval Operations in the Civil War
No full textBlockades, commerce, and amphibious assaults Author braids together three major themes Now for the Contest, by William Roberts, is the story of the naval war at sea during the Civil War. Roberts\u27s narrative, however, does not take the usual shot and shell or great leaders ...
Tobacco hands
No full textThesis (M.A.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.2999-01-0
Reading forests: Contested ideologies and forest use in British Columbia.
No full textThis thesis examines the interconnection between existence, culture, and ecology. Taking an interdisciplinary approach, I tie together anthropological discussions of culture, French philosophy, and forestry with locally inspired narratives. Specifically, I examine Brian Fawcett's Virtual Clearcut: The Way Things Are In My Hometown and Des Kennedy's The Garden Club and the Kumquot Campaign, a 'testimonial documentary' and a novel respectively. Both narratives illustrate local connections, histories, interpretations, and contentions concerning forest use through a central theme of logging. The narratives reflect the Romantic literary tradition of the pastoral, while focusing on ecocentric considerations. Overall, by drawing from Felix Guattari's ecosophy I avoid favouring anthropocentric or biocentric tendencies, thus acknowledging the importance of the role of subjectivity and multiplicity in ecological debates, which allows me to conclude that debates concerning forest use can no longer be polarized.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b136235
“Explorers in the further regions of experience”: Late twentieth-century body horror’s subversion of Victorian monsters and modern sex politics
No full textThis thesis explores the body horror subgenre of film, its creation and rise in popularity during the late twentieth century (1975-1995), and how the subgenre’s grotesque and unsettling examination of the human body, its form, and reproductive processes, allowed body horror filmmakers to tackle societal taboos regarding the human body and one’s sexuality. By comparing and contrasting the body horror subgenre with both its contemporary the slasher subgenre and its thematic sexual origins within Victorian Gothic fin de siècle horror fiction, this thesis will provide evidence that the subgenre makes significant strides within the horror genre to push a more progressive narrative and representation of men, women, and the LQBTQ+ community, through its deconstruction of the human body/form, sexuality, and reproductive processes. Through a detailed breakdown and analysis of Ridley Scott’s Alien (1979), David Cronenberg’s Shivers (1975) and The Fly (1986), Clive Barker’s Hellraiser (1987) and Nightbreed: The Director’s Cut (2014), and Roger Donaldson’s Species (1995), this thesis will demonstrate how filmmaking techniques, themes, and narratives of these films, deconstruct previous notions of the human body and sexuality within the horror genre, and encourage audiences to re-evaluate the body, and the roles/positions/pressures society has created around sexuality and perceived sexual taboos and fears
Constructing new Camelots: Representations of sexuality, gender and religion in Arthurian legend and their manifestations in contemporary writing and culture.
No full textNo abstract available.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b119193
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