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.
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 most users are familiar with broadband velocity sensors, this is now the default output from the Prism. We have taken the acceleration output from the sensors and converted it to produce recordings in velocity, with a flat velocity frequency response from 30 seconds to 80Hz. The acceleration output version (with a flat acceleration response from 200 seconds to 1500Hz) is available on request.
Data Sheets: Gecko Prism