HR: 0830h
AN: NG11A-0168    [PDF]
TI: Toward the standardization of image analysis from X-ray tomography: Applications to vesicular rocks used for paleoelevation studies
AU: Sahagian, D
EM: dork.sahagian@unh.edu
AF: EOS and Earth Sci., University of New Hampshire, Durham, NH 03824
AU: * Proussevitch, A
EM: alex.proussevitch@unh.edu
AF: EOS and Earth Sci., University of New Hampshire, Durham, NH 03824
AB: We have developed a technique for measuring paloelevation through the study of vesicular basalts. It is based on determining size distributions of vesicles from x-ray tomographic data. The data requires further processing to separate partially coalesced or closely adjacent vesicles. We have found that peeling and reconstruction of voxel layers is an effective means of identifying individual entities within a complex structure from tomographic image data. In order to accomplish this, several steps are involved, some of which have traditionally required ad hoc interpretation on the part of the user. These include selection of thresholds between vesicle and rock, criteria for splitting apart partially coalesced vesicles, construction of a binning grid for resulting vesicle size classes, and interpretation of resulting histograms. With a more standardized procedure, it is possible to remove (at least partially) user input in the step by step process, thus increasing portability of the technique. The reduction of the large number of user-defined parameters in the sample analysis will make it possible to further automate the process, thus enabling faster processing and greater sample throughput. It also increases the reproducibility of results between labs or investigators analyzing similar rocks. This will be necessary for any large-scale studies of paleoelevation involving multiple labs and large numbers of sample analyses.
DE: 3210 Modeling
DE: 3230 Numerical solutions
DE: 3299 General or miscellaneous
SC: Nonlinear Geophysics [NG]
MN: 2003 Fall Meeting