An Overview
Major: Geophysics
Academic Affiliation: University of Texas at El Paso
Abstracts
2007- Development of a power and communication system for remote autonomous GPS and seismic stations in Antarctica
We are addressing the challenge of operating a permanent GPS station in the harsh environment in Antarctica. The power and communication systems must operate year-round in the polar region where it is freezing, windy, and dark during the winter. We are working on three major parts of the GPS station: improving the power system, communication system, and mechanical design. We are investigating four areas related to the design of permanent GPS stations for the polar regions. 1). Analysis of wind power data was performed to compare wind speed versus power generated from wind turbine. 2). A test series was performed by applying varying voltages to power ports A and B of a GPS receiver. This was done to understand the power switching behavior of the receiver when it is powered from two independent sources. 3). A battery tester was evaluated to determine its accuracy. This tester may be used by engineers in the field to evaluate battery health, so ensuring its accuracy is critical. 4). Testing to determine GPS receiver and Iridium antenna interference was also done. This testing focused on understanding what distance between antennas was necessary to reduce the interference. The data and experiments with the equipment produced helpful results for the project and will improve permanent GPS technology for the polar regions.
2008- Drilling induced Fracture (DIF) characterization and stress pattern analysis of the Southern McMurdo Sound (SMS) Core, Victoria Land Basin, Antarctica
There is a significant lack of data about present-day stress fields in Antarctica. Stresses provide valuable information about the forces acting on tectonic plates. In Antarctica, stresses may be related to ridge forces such as rifting and/or uplifting, to ice loading/unloading-related processes, or both. This project studies drilling induced fractures from core recovered in the Victoria Land rift basin of Antarctica. Drilling induced fractures form ahead of the drill bit during drilling from stress imbalances due to the removal of excess weight pressure around the rock. Because horizontal stresses strike parallel to the planes made by drilling induced fractures, they can be used to measure modern-day stress fields. Whole core images obtained during core logging by digitally scanning the outside of the core are stitched into longer intact intervals. Drilling induced fractures in the core are ‘picked’ to obtain their azimuth. Magnetically oriented acoustic images of the inside of the drill hole are then compared side by side with the stitched whole core images and visually scanned for matching features. Once the same set of fractures is found in the core and the borehole, it is then possible to rotate core images to match the orientation of the borehole image. This will produce a core image with all the fractures in that interval re-oriented to true north. This final orientation of drilling induced fractures in the core will thus provide the direction of maximum horizontal compressional stress in this area.