Richter is used by scientists and newspapers. The Modified Mercalli Index is used by earthquake people and disaster control & emergency services folks. That's because scientists want to know how powerful an earthquake is but emergency people want to know what it did.

Penny, you constantly surprise me. I've not met anyone before, other than experts, who knew about Mercalli.

Those of you who live in earthquake areas can take some simple steps to reduce damage in your own homes.
1. Chain your water heater to the wall.
2. Fit an earthquake valve to your propane tank or gas line.
3. Fix heavy bookshelves and cabinets securely to the walls.
and so on....

Bert.