What is VORTEX?
RSAM stands for Real-time Seismic-Amplitude Measurement. It represents the overall signal size over periods of 10 minutes. In situations when the number of earthquakes is so high that individual earthquakes can’t be seen, or the level of volcanic tremor is such that seismograms no longer show a change in signal level, then RSAM is an excellent way of showing changes with time.
SSAM stands for Seismic Spectral-Amplitude Measurement. It shows the relative signal size in different frequency bands. Using SSAM it is possible to get an idea of whether a signal is produced by earthquakes, by wind or traffic noise, or by volcanic tremor. Earthquakes, wind and traffic noise all tend to have energy at a wide range of frequencies (a wide-band signal), while volcanic tremor tends to have energy in a more limited range of frequencies (a narrow-band signal).
In addition to these two techniques VORTEX integrates also other sensor data like video data to provide a more complete picture of the ongoing situation.