Know Your Scales
On May 22, 1960, an earthquake (the largest recorded on a seismograph) measuring 9.5 on the Richter scale struck Chile. Named after American seismologist Charles Francis Richter, the scale reflects ground shaking and the energy released. The Richter scale is logarithmic, so each number represents ten times the number below. Thus a “5″ is ten times greater than a “4″ and it releases more that 30 times the amount of energy. The Modified Mercalli Scale, named after Italian volcanologist Giuseppe Mercalli, reflects the level of damage caused by an earthquake. Expressed in Roman numerals, a”I” indicates that people do not even feel the quake, and a “XII” indicates catastrophic destruction.
Help the people in your circle of influence become more informed participants in public preparedness conversations by sharing these distinctions.
