We have talked about intensity a few times (The boss' blog) but i thought I'd do a wee reminder as lately we have had a few comments on recent quakes such as "that felt bigger than a 3.3" etc. Now magnitude isn't the best indicator of how the earthquake was felt, as it depends on other factors such as depth.
This is where Intensity comes in, we have used intensity on our new website - its based on a number scale but we have added in words and colours to make it easier/quicker to see. You can see below, the scale ranges from MM1 - unnoticeable (which may be felt by some people) to Severe - which covers damaging up to worse case scenario MM12.
So next time you look at an earthquake, check out its intensity - it will give you a better idea of the effects the quake had on people/buildings etc. on the surface.
Both the September 4th Darfield earthquake and the Feb 22 Christchurch earthquake were MM9.
The 1855 Wairarapa and 1931 Hawkes Bay earthquakes both had an intensity of MM10!