1,479 research outputs found
The Great Unsolved Mysteries in Canadian History Project
Everybody loves a murder mystery. Of all the historical situations researchers encounter nothing has quite the same impact as discovering an innocent person hanged, a guilty person going free. Co-directors of the GREAT UNSOLVED MYSTERIES IN CANADIAN HISTORY project located at the University of Victoria, John Lutz (Department of History, University of Victoria) and Ruth Sandwell (Ontario Institute for Studies in Education of the University of Toronto), have just received funding from the Canadian Content Online Program (CCOP) of the Canadian Heritage Ministry to move ahead with phase two including two new mysteries “What happened to Aurore Gagnon?” (Peter Gossage, Research Director) and “Nobody Knows His Name: Klatssasin and the Chilcotin Massacre” (John Lutz, Research Director) to complement
the pilot “Who Killed William Robinson?”
Evidence for retrograde lithospheric subduction on Venus
Though there is no plate tectonics per se on Venus, recent Magellan radar images and topographic profiles of the planet suggest the occurrence of the plate tectonic processes of lithospheric subduction and back-arc spreading. The perimeters of several large coronae (e.g., Latona, Artemis, and Eithinoha) resemble Earth subduction zones in both their planform and topographic profile. The planform of arcuate structures in Eastern Aphrodite were compared with subduction zones of the East Indies. The venusian structures have radii of curvature that are similar to those of terrestrial subduction zones. Moreover, the topography of the venusian ridge/trench structures is highly asymmetric with a ridge on the concave side and a trough on the convex side; Earth subduction zones generally display the same asymmetry
Undersea volcano production versus lithospheric strength from satellite altimetry
All seamount signatures apparent in the SEASAT altimeter profiles were located and digitized. In addition to locating the seamount signatures, their amplitudes were also estimated. The second phase consisted of determining what basic characteristics of a seamount can be extracted from a single vertical deflection profile. Seven seamounts that had both good bathymetric coverage and good satellite altimeter coverage were used to test a simple flexural model. A method was developed to combine satellite altimeter profiles from several different satellites to construct a detailed and accurate geoid
The gravity field of topography buried by sediments
The gravity field over topography in the northern Indian Ocean that was completely buried by sediments of the Bengal Fan was investigated to understand the effect of sedimentation on the continental gravity field. An isopach map made from the seismic reflection and refraction in the Bay of Bengal shows two prominent N-S trending features in the basement topography. The northernmost portion of the Ninetyeast Ridge is totally buried by sediments north of 10 deg N. The other buried ridge trends roughly N-S for 1400 km at 85 deg E to the latitude of Sri Lanka and then curves toward the west. It has basement relief up to 6 km. Two free air gravity anomaly profiles across the region show a strong gravity low over the 85 deg E ridge, while the Ninetyeast Ridge shows a gravity high
Rural Reconstruction: Towards a New Synthesis in Canadian History
Recent works in the field of rural history are offering a critical challenge to the
historiography of nineteenth- and early twentieth-century Canada. The first part of
this article draws on a variety of rural studies to outline some problems that arise
in the growing discord between recent literature on rural Canada and traditional
Canadian historiography. These anomalies are linked to an historical discourse that
trivializes and obscures what is arguably the most important institution of rural
society: the household. Finally, the author reviews some recent rural studies that
explicitly search for ways to give the pre- and post-industrial rural household a
conceptual depth that it lacks within the constraints of neoclassical and Marxist
'evolutionist' constructions of the political economy.Les travaux récents dans le domaine de l'histoire rurale mettent en doute l'historiographie
du Canada du 19e siècle et du début du 20e siècle. La première partie de
l'article est fondée sur diverses études rurales et souligne quelques-uns des problèmes
causés par l'écart qui s'agrandit sans cesse entre les ouvrages récents sur
le Canada rural et l'historiographie canadienne traditionnelle. Ces anomalies sont
reliées à un discours historique qui rend banale et obscure l'institution qui est
probablement la plus importante de la société rurale, soit le foyer. Enfin, l'auteur
examine certaines études rurales récentes dans lesquelles on cherche explicitement
des moyens de donner aux foyers canadiens remontant aux périodes pré-industrielle
et post-industrielle, la profondeur conceptuelle qui leur manque, compte tenu des
contraintes imposées par les interprétations évolutionnistes néoclassiques et marxistes
de l'économie politique
Studies of oceanic tectonics based on GEOS-3 satellite altimetry
Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed
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