HR: 15:10h
AN: T52D-07    [PDF]
TI: A Collaborative Approach for Providing Low-Cost ELF Monitoring from Ground and Space
AU: * Bleier, T E
EM: tbleier@quakefinder.com
AF: QuakeFinder,LLC, 250 Cambridge Ave Suite 204, Palo Alto, Ca. 94306 United States
AU: Franklin, L
EM: lfranklin@quakefiner.com
AF: QuakeFinder,LLC, 250 Cambridge Ave Suite 204, Palo Alto, Ca. 94306 United States
AB: This paper describes a collaborative effort among several groups, including a small business (QuakeFinder,LLC), dozens of high schools in northern California, several universities (Stanford and Cal Poly SLO), and Lockheed Martin in Sunnyvale to build a combined ground-based and space-based ELF monitoring system. The goal is to monitor and characterize the raw RF spectrum in the ELF band, and to look for pre- and post-earthquake signatures. Previous attempts at monitoring ELF signals associated with earthquakes have always been summarized with the statement, {\bf more data is needed}. QuakeFinder is a small business that approached the problem with a different strategy. Rather than deploy a few, expensive, commercial high sensitivity, AC magnetometers on the ground, a collaboration was formed with high school physics classes to build a large number of medium sensitivity magnetometers from partially-assembled kits, and to deploy these sensors in a close spacing along the major California earthquake faults. The strategy was to have a 3-axis ELF ground monitor within 15 km of any large ($>$M5) quake-- before, during, and after the event. To date, 34 sites have been deployed (out of 50 planned), and they now collect and display daily averages from these 3-axis monitors on a web site (www.earthquaketracker.com).\\ Likewise, satellite-based monitoring is severely restricted by the high cost of building and flying space-based ELF monitors. QuakeFinder formed a collaboration between Stanford Space System Development Laboratory and Lockheed Martin to design and build a nano-satellite (4.5 kg) whose mission was to collect ELF background signatures. QuakeFinder built and donated a single axis ELF (1-1000Hz) magnetometer payload and provided integration and a launch opportunity for "QuakeSat I". The satellite was launched on June 30, 2003 into a 820 km circular polar orbit, and has recorded natural signals (lightning, whistlers, auroral noise, and several unidentified signatures) as well as man-made (radar) signals. At this writing, it is early in the project, and more signal analysis and statistics are needed to determine if earthquake-related signals are present. The paper will report on the result of QuakeSat tasking over epicenters of $>$M6 earthquakes for post seismic correlations, and over seismically active areas worldwide for pre-seismic correlations of increasing ELF signals.
DE: 1555 Time variations--diurnal to secular
DE: 8194 Instruments and techniques
DE: 8199 General or miscellaneous
SC: Tectonophysics [T]
MN: 2003 Fall Meeting