Playing around with "Event Intensity" in Google brings up interesting results including this: http://www.transboundarywaters.orst....bar_scale.html
The -40 on the dial could correlate to -4 on this scale.
Playing around with "Event Intensity" in Google brings up interesting results including this: http://www.transboundarywaters.orst....bar_scale.html
The -40 on the dial could correlate to -4 on this scale.