Along the same lines as Peter Aldhous's view of Japanese quakes since 1900, Alex Kerin's view below allows us to see seismic activity over the past week. The redder dots indicate stronger quakes.
The histogram on the sidebar is of particular interest here... you can see there were almost ten quakes above 6.0 on the Richter scale.
Earthquakes in Japan (Last 7 Days)
Tableau was pretty amazing. It was extremely easy to use and – it was extremely fast.