The Seismology Research Centre (SRC) division of ESS Earth Sciences has had a big year in 2016: celebrating its 40th anniversary since local earthquake monitoring began in 1976; and in the development and release of several new and improved products, the latest being the Gecko Prism broadband seismograph, and a portable power solution for remote installations called the Power Tent.
The Gecko Prism, an acronym for Portable Rugged Interferometry SeisMograph, is the result of 18 months of testing of a new compact sensor technology that uses laser optics and interferometry to detect nano-g levels of motion, being particularly sensitive to low frequencies (periods as long as 200 seconds) and very high frequencies (to 1500Hz) while maintaining a high clip level, giving a huge dynamic range of motion.
By recording acceleration at high resolution, a wider range of motion can be detected than a velocity sensor can manage, much like velocity sensors were able to detect a wider range and higher resolution of motion than the original displacement seismographs like that developed by John Milne, one of which was installed in Melbourne, Australia, the home of the SRC.
As with most modern electronics, low power consumption and miniaturisation have made modern seismic equipment much more portable, but long term monitoring still requires a long term power source. Most outdoor seismic stations operate in enclosures powered by solar panels and batteries, and using our engineering and field experience we have developed an ultra-portable power system for low-power devices that will keep a seismograph operating indefinitely.
We call it the Power Tent, and it can be built as a 20W, 30W, 40W or 60W solar system with LiFePO4 (lithium) batteries or flight-safe NiMH (Nickel Metal Hydride) batteries, providing power autonomy if solar exposure is limited for extended periods. Weighing as little as 4.5kg and only 50mm thin, the folding Power Tent is the perfect companion for the Gecko SMA-HR, Helix, or Prism for aftershock and other rapid-deployment seismic surveys.