March 11 Earthquake

Japan is still trying to recover after the massive 9M Tohoku earthquake that struck about 2 weeks ago followed by a huge destructive tsunami of wave height of up to 23m.  So far, the official fatalities are over 10,000 with the number quite likely to be at least 25,000 based on the number of missing.  Plus, the nuclear power plant in Fukushima is still having serious problems and very difficult work is done to cool it down.  The areas around the plant do have higher radiation readings.  Tokyo (which is around 250 km away) also has about twice of it's normal radiation (which is not of health concern).  In Nagoya (450km away) there doesn't seem to be an increase of radiation.  There are also problems with power and control blackouts are being implemented to share the load.  Power cannot be shared from West Japan (e.g. Nagoya) since it is a different grid with different Hz.  Not a very good situation but I do admire the Japanese people's handling of this crisis - I think it would be more of a mess in other countries.

Well, regardless of the situation, here are some really interesting facts about the power of such an earthquake.  First of all, this large of an earthquake can only happen in a subduction zone where basically two plates collide and slide under each other which is primarily around the Pacific Ring of Fire.  90% of the world's earthquakes happen there and around 75% of the world's volcanoes are situated in it.

The Geospatial Information Authority of Japan has some amazing maps showing how much the main Japanese island (Honshu) has moved (or twisted) due to the earthquake.  On their website, you can find a map of the movement towards the earthquake epicenter.  One peninsula moved 5.3m.  Also, here is a map that shows the downward movement.  That same peninsula dropped around 1.2m and many of the coastal areas that got flooded by the tsunami moved down around 0.5m.  Since the earthquake (I guess due to the aftershocks) the land mass still continues to move.

The USGS has a nice interactive aftershock map.  So basically, here are the stats at this time:
8-9M: 1 (the original 9.0M)
7-8M: 2 (aftershocks shortly after the main earthquake)
6-7M: 41 aftershocks
5-6M: 341 aftershocks
4-5M: 457 aftershocks

I felt 3 of those - the main quake, the first 7.9M aftershock, and the 6.2M quake between Tokyo and Nagoya (a different fault line but still probably due to the other earthquake).

Edit: here is an awesome youtube animation of the aftershocks:


That is the power of nature.