Electric Currents in Granite and Gabbro Generated by Impacts Up To 1 km/sec
Abstract
For many years, radio noise, strange lights coming out of the ground, and other unusual phenomena have been detected prior to major earthquakes. Only recently have these signals been systematically monitored and their correlations to earthquakes have been more firmly established. A glow in the sky sometimes heralds a big quake. In January 1995, white, blue, or orange lights extending some 200 m into the air and spreading 1 to 8 km across the ground were reported by at least 23 eyewitnesses in and around Kobe, Japan. Hours later, a 6.9-magnitude earthquake killed more than 4,500 people. Such signals imply the movement of electric currents through rock and soil and their discharge into the air. During summer 2006 a research project started using the single-stage light gas gun at the NASA Goddard Space Flight Center in Maryland. The gun fires 63 mm diameter aluminum sabots of a few grams to 1.2 kilograms. A catcher was designed to stop the sabot while allowing a smaller projectile to impact a desired target at velocities up to 1 km/s. This presentation documents first results of the production of electric currents during impacts on granite and gabbro instrumented with capacitive sensors, contact electrodes, magnetic pick-up coils and photo diodes for light detection. This research is critical towards the development of techniques that could be used to monitor quakes on the Earth and estimate secondary effects of meteorite impacts on the Moon and Mars during the next phase of human space exploration.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.T31A0419H
- Keywords:
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- 1209 Tectonic deformation (6924);
- 1240 Satellite geodesy: results (6929;
- 7215;
- 7230;
- 7240);
- 5420 Impact phenomena;
- cratering (6022;
- 8136);
- 6929 Ionospheric physics (1240;
- 2400);
- 8168 Stresses: general