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 ...

Though primarily designed to quantify earthquakes, the Richter scale can also measure the magnitude of large explosions. This capability stems from the fact that both release energy that travels ...