Completing the Global Seafloor Fabric and Magnetic Lineation Project

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The detailed description and distribution of seafloor lineated fabric and magnetic isochron picks are fundamental to plate kinematics. A complete and global characterization of these data will represent a major milestone in marine geophysical research. Self-consistent data may reveal subtle patterns and will reduce uncertainties in model parameters deduced from them. Plate tectonic reconstructions form the basis for much geologic research. The improvements that this framework will make possible will be felt over a wide cross-section of the Earth sciences. In addition, the availability of global, self-consistent seafloor fabric traces will impact numerous lines of marine research. As with most infrastructure projects, this project will by its nature have wide impact. All software developed will be made available and compatible with GMT5. The Generic Mapping Tools, GMT, are an open source collection of tools for manipulating geographic and Cartesian data sets and producing PostScript illustrations. Graduate and undergraduate students will be involved in this project and learn valuable skills pertaining to marine geophysical research and data analysis. The public will obtain access to the results of this work via data repositories and the project web site. This project is a follow-up to a two-year previously funded NSF pilot project ("The Global Fracture Zone and Magnetic Lineation Project"). The previous project sought to (a) initiate an online database of global fracture zones (FZs), (b) develop Matlab software to digitize and refine FZs based on available grids, and (c) provide an online collection of published magnetic lineation picks. Progress has been made on all fronts with access to preliminary data presently available on the project website. The scope of the project has expanded in that the digitization of fracture zones had to be extended to include other types of related lineated seafloor fabric (such as propagating rifts, discordant zones, and V-anomalies-linear gravity lows that trace out a 'V' shape at present-day mid-ocean ridges). The software the Principle Investigator is developing is not yet fully complete, partly due to a dependency on GMT5, which has just recently been released. Google Earth is being used to digitize and write two C programs: one cross-profile analyzer (fzanalyzer) and one filtering tool (fzblender). This project will extend the initially funded work an additional year to complete the software testing, documentation, and packaging into a supplement and to finalize scripting for the website. The one-year follow-on project aims to accomplish these specific goals: 1. Complete the development of fzanalyzer and fzblender, with support scripts, into a regular GMT5 supplement, including a technical report to document tools, their purpose and operation, with examples for others to emulate. 2. Publish a G3 technical brief on the project, thereby announcing its availability to the broader community of potential users. 3. Continue the compilation of magnetic lineation picks via the EarthByte collaboration and document/automate the upkeep of the web site. 4. Add David Sandwell's divergent plate boundaries to the database. 5. Ensure all data can easily be imported into Google Earth, GeoMapApp and GPlates and seek a permanent repository with the Marine Geoscience Data System (MGDS) and NOAA's National Geophysical Data Center (NGDC).