Seismicity Monitoring Techniques
These images show RSAM and SSAM plots during the last month at a station in the Northland Volcanic Area.
RSAM (Real-time Seismic-Amplitude Measurement) and SSAM (Seismic Spectral-Amplitude Measurement) are techniques that permit volcano seismologists to evaluate the nature of seismicity at a volcano. They are able to recognize subtle shifts in frequency related to changing dynamics of magma or gas movement within the volcano, or the amount and style of volcanic tremor. They also show other noise like windy weather or traffic.
