Since we are in a time of Earth changes I thought it might be helpful to post a scale to help us all remember the severity of earthquakes as they occur.
9.0M or greater
Can totally destroy communities near the epicenter.
• 1964 Alaska earthquake 9.2M
• 2004 Indian Ocean 9.1
8.0M or greater
• 2010 Chile 8.8M
Also considered by some a MegaThrust.
7.0 to 7.9M
Can cause serious damage.
• 1950 Costa Rica (Nicoya Pennensula) 7.7M
6.1 to 6.9M
May cause a lot of damage in populated areas.
5.5 to 6.0M
Slight damage to buildings.
2.5 to 5.4M
Often felt but w/minor damage.
2.5M or less
Usually not felt, but may be recorded.
Sources: UPSeis, Wikipedia, MSNBC.