August 1, 2012.
The definitive version is available at http://dx.doi.org/.
This research effort is part of an ongoing investigation into stress-activated positive hole charge carriers in common igneous and high-grade metamorphic rocks. The findings have already revealed potential early earthquake detection mechanisms and caused a re-think on the processes that could conceivably contribute to the formation of and evolution of life. Positive holes are defect electrons in the oxygen anion sub-lattice of silicate minerals that have demonstrated some intriguing capabilities: flowing out of a stressed rock volume; causing oxidation reactions at the rock-water interface and ionization at the rock-air interface; and traveling great distances. This research seeks to determine if obsidian (volcanic glass) is also capable of yielding stress- or temperature-activated charge carriers.
In this study, a measurable change in current and voltage when obsidian samples are put under mechanical stress would suggest that charge carriers are available. The motivation for this research, among other reasons, is that it will add breadth to positive hole phenomena; provide additional evidence for stress- or temperature-activated positive hole formation; and create possibilities for monitoring volcano activity.
Geophysics and Seismology
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013 and Grant No. 0833353. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).