Campaign geodetic observations demonstrate shallow, interplate coupling along the thrust fault between the converging oceanic Nazca and continental South American plates. Delimiting the width of the seismogenic zone contributes to our understanding of the seismic and tsunamigenic nature of convergent plate boundaries. Here we locate the updip limit of the seismogenic zone using a combination of the Global Positioning System (GPS) and acoustic travel time measurements.Two seafloor transponder arrays were positioned in 2001 and 2003, providing plate motion vectors 20 and 50 km landward of the Peru-Chile trench axis at 12_S. Over 100 hours of GPS, acoustic and sound speed profiling data were gathered at each array, in each epoch, providing an estimate of plate motion with an uncertainty on the order of millimeters. I describe each component of the GPS-acoustic technique (GPSA), including static and kinematic GPS, GPS antenna-hydrophone baseline surveys, acoustic travel time measurements, sound speed profiling and moving surveys to determine a priori transponder position. Comparing these geodetic measurements with three dimensional kinematic models reveals coupling at less than 2 km depth. Seismic records, thermal models, and topographic analyses suggest that GPSA array displacements represent shallow, elastic strain accumulation. Transponder relocation, another key component of this technique, consists of surveying a replacement transponder in the event that a transponder becomes inactive. I discuss the methodology and results of a transponder relocation, which contributed ±19 mm uncertainty to the final array vector. Optimal survey network geometry for a transponder relocation was determined in a simulation of the least-squares adjustment. Future relocations could decrease the contribution to array uncertainty to ±10 mm with improved survey geometry. Finally, complimentary investigations such as long-baseline kinematic GPS, transponder depth measurements and near-bottom acoustic surveys are included as necessary asides for the development seafloor geodetic observations

In (Re)creating Social Life Out of Social Death I analyze literary representations of historical cross-cultural alliances and political coalitions forged between subaltern groups. I argue that black Atlantic writers promoted intersubjective alliances in an attempt to address experiences of familial, cultural, and political alienation associated with the transatlantic slave trade, the philosophical foundations of Western Enlightenment, and the modern formations of liberalism. As many critics have shown, black Atlantic authors and texts promoted black personhood by simultaneously engaging with and reconfiguring western notions of literacy and self- possessive individualism. However, these studies tend to overemphasize the individual self-fashioning of black identities at the expense of interpersonal, reciprocal relations. While black Atlantic authors and texts do highlight liberal individualism as a component of subjectivity, they also frame extreme individualism as a socially isolating component of western modernity. In doing so, they represent interpersonal relationships and collective experiences as integral to one's understanding of personhood. Intersubjective recognition among black and Native subjects posed another form of resistance to the modern formation of the liberal subject as a rational, autonomous, political individual subject free from political and psychological dependence on others. My study draws from and builds upon a growing body of scholarship emphasizing the importance of collectivity in eighteenth- century black Atlantic writing. However, these studies tend to emphasize relations among saltwater and plantation slaves. In contrast, my analysis addresses the active presence of Native culture and Native cultural ideas about political alliances, interpersonal networks, and notions of intersubjective belonging. Using the writings of Briton Hammon, Olaudah Equiano, and Paul Cuffe, I argue that black Atlantic writings from this period were part of larger, transnational conversations about and struggle over early meanings of cross-cultural, black-Native, intersubjectivity. In many cases, these alliances reconfigure human interdependence among people of color as positive features of human collectivity, rather than as degraded forms of pre-modern humanity