How do you measure the size of a volcanic eruption? Just as seismologists measure the size of an earthquake using the Richter scale, volcanologists use an eruption magnitude scale called the ...

Earthquake Magnitude Scale Magnitude Earthquake Effects Estimated Number Each Year 2.5 or less Usually not felt, but can be recorded by seismograph. Millions 2.5 to 5.4 Often felt, but only causes ...

I Felt by very few people; barely noticeable. II Felt by a few people, especially on upper floors. III Noticeable indoors, especially on upper floors, but may not be recognized as an earthquake. IV ...

The CMC’s approach will mirror the methodologies used for physical events, such as the Richter scale for earthquakes and the Saffir-Simpson hurricane wind scale for hurricanes. After a year in stealth ...