Earthquake

Well, I guess the 7M earthquake a few days ago was not enough, today was another similar (around 7M - USGS lists it as 6.6M) earthquake - this one actually on land but in that general area.  I felt it slightly at school - basically something like 4 "waves" only.  The intensity in Nagoya was 2.  Today also marks the 1 month anniversary of the devastating quake and tsunami.

Earthquake!

About an hour ago, there was a 7.4M (preliminary) aftershock of the large earthquake that hit almost a month ago.  That was the largest aftershock to date.  Not very surprisingly since there was quite a bit of talk about the probability of a 7+ aftershock.  Here is the intensity map:

So basically, it was felt throughout most of Japan.  In Nagoya, the intensity was 2 so I felt it in my apartment but it was not as much as the one that happened between Tokyo and here a few weeks ago (which was intensity 3) or the original quake (which was intensity 4).

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.

Earthquake near Nagoya

Probably related to the large earthquake a few days ago, today evening was an earthquake between Tokyo and Nagoya (in Shizuoka) with preliminary magnitude of 6.4.  I felt that one quite nicely on the 11th floor of my apartment.  About the same feeling as the large earthquake a few days ago but a bit shorter.  Here is the intensity map:

This one happened on land so no tsunami.

Regarding the 9.0 earthquake that happened a few days ago, here is a map of the aftershocks to date (483 on this map).  Many of them 5M and above:

Crazy!  The red square between Nagoya and Tokyo is the one I described above.

Edit:
I forgot to mention something I wanted to mention.  I was talking to one of my lab members in the lab today about this whole earthquake thing and he said something that I felt very profound and quite interesting.  The Japanese islands were basically formed due to the same forces that cause these earthquakes... so this is Japan... this is (including the earthquakes, the volcanoes, the tsunamis) home for Japanese people!

If you are interested in how the Japanese islands formed, you can find a good description on this site.

Huge Earthquake hits Japan

Just writing this up so that people don't worry about me.

Today a few hours ago was a huge earthquake in northeast Japan.  How big?  Well, the USGS puts it at 8.9M making it the 7th most powerful earthquake recorded in the world and the biggest recorded in Japan.  So... BIG!    It happened off the coast 130km east of the city of Sendai and around 370km away from Tokyo.  There were reports of people feeling it in Beijing, China.  Here is the intensity map of the earthquake from JMA (the scale is shown):

Basically, parts of Tokyo felt the earthquake at intensity 5+ and Nagoya at 4.

I was at university in the lab.  It started off quite slowly feeling the building slightly rock... then it increased... at some point the building felt like it was made out of rubber swinging so slightly.  The shaking was not too bad and didn't make anything fall down but it was definitely noticeable.  It let go for like a minute and started shaking again.. all in all probably a few minutes of gentle rocking.  I also felt some of the larger aftershocks that followed.  Here is a list of the pre/after shocks up to now since they are still going on and will for a while:

MAP	5.6	2011/03/11 10:20:27	36.966	142.289	21.7	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.0	2011/03/11 10:10:34	39.248	142.779	28.9	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/11 09:59:56	36.703	142.207	41.6	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.5	2011/03/11 09:47:01	39.685	142.938	29.7	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/11 09:42:22	39.438	142.749	30.2	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.4	2011/03/11 09:37:08	35.877	141.585	29.9	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.5	2011/03/11 09:09:14	37.717	143.267	36.2	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.4	2011/03/11 09:04:10	37.299	142.655	30.5	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/11 09:00:19	37.056	141.966	20.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.4	2011/03/11 08:52:26	36.763	141.910	35.8	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.5	2011/03/11 08:46:47	37.421	142.453	37.3	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.9	2011/03/11 08:40:56	37.465	141.122	38.6	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.1	2011/03/11 08:31:07	37.428	141.200	25.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.5	2011/03/11 08:19:24	36.200	142.000	19.9	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.2	2011/03/11 08:15:40	37.034	144.612	27.8	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.2	2011/03/11 08:12:04	36.606	141.557	19.8	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.5	2011/03/11 08:10:30	36.394	140.631	30.4	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.9	2011/03/11 08:01:58	37.071	142.734	22.6	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.6	2011/03/11 07:56:15	37.130	142.305	34.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.7	2011/03/11 07:54:44	37.742	141.565	45.3	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.8	2011/03/11 07:42:55	36.406	141.919	29.9	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.9	2011/03/11 07:38:26	39.250	142.783	29.1	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.1	2011/03/11 07:28:12	36.802	141.911	24.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.1	2011/03/11 07:25:33	37.916	144.621	15.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.3	2011/03/11 07:14:59	36.648	141.811	25.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.9	2011/03/11 07:13:47	36.051	142.347	28.5	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.8	2011/03/11 07:10:59	37.899	142.734	30.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.3	2011/03/11 06:57:14	35.758	140.992	30.2	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.3	2011/03/11 06:48:47	37.993	142.764	22.3	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	7.1	2011/03/11 06:25:50	38.106	144.553	19.7	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.8	2011/03/11 06:15:40	36.186	141.192	35.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.4	2011/03/11 06:07:21	36.401	141.862	35.4	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.4	2011/03/11 06:06:11	39.025	142.316	25.1	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	8.9	2011/03/11 05:46:23	38.322	142.369	24.4	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	4.9	2011/03/10 22:44:25	38.844	143.006	34.2	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.7	2011/03/10 21:49:46	38.590	143.086	26.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/10 16:54:45	38.053	143.253	4.7	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.1	2011/03/10 11:21:08	38.611	143.049	17.6	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/10 09:02:21	38.652	143.146	21.9	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/10 08:59:19	38.547	143.295	19.8	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.7	2011/03/10 08:08:20	38.630	143.304	17.2	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/10 07:33:04	38.954	142.458	20.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	4.6	2011/03/10 04:14:00	38.406	143.427	31.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.0	2011/03/10 01:20:23	38.408	143.033	25.1	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/09 23:57:41	38.308	143.275	20.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.4	2011/03/09 23:37:00	38.438	143.185	32.8	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.1	2011/03/09 21:22:18	38.385	142.642	23.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	4.9	2011/03/09 21:00:57	38.267	142.580	22.5	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	6.0	2011/03/09 18:44:35	38.502	143.199	23.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	6.1	2011/03/09 18:16:14	38.378	142.506	22.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/09 14:24:05	38.589	143.226	10.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.7	2011/03/09 12:03:17	38.358	143.119	13.1	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.1	2011/03/09 11:27:51	38.529	143.040	28.2	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.7	2011/03/09 10:13:39	38.721	143.090	27.2	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/09 08:55:38	38.667	143.055	15.6	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.3	2011/03/09 08:02:36	38.606	143.103	15.4	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.1	2011/03/09 07:56:27	38.849	142.929	10.7	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.0	2011/03/09 07:13:48	38.246	143.108	9.9	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.1	2011/03/09 06:25:12	38.299	143.067	10.8	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.9	2011/03/09 06:12:13	38.681	143.022	10.0	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.3	2011/03/09 04:45:54	38.543	142.740	27.0	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.7	2011/03/09 04:37:03	38.666	142.991	25.5	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/09 04:32:10	38.727	143.001	32.1	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	4.8	2011/03/09 04:15:39	38.857	142.658	12.6	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/09 04:05:53	38.870	142.420	10.9	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.0	2011/03/09 03:19:00	38.795	142.962	19.9	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	5.2	2011/03/09 03:08:35	38.339	143.097	24.4	OFF THE EAST COAST OF HONSHU, JAPAN
MAP	5.6	2011/03/09 02:57:16	38.402	142.825	17.5	NEAR THE EAST COAST OF HONSHU, JAPAN
MAP	7.2	2011/03/09 02:45:20	38.424	142.836	32.0	NEAR THE EAST COAST OF HONSHU, JAPAN

I have highlighted the main one in yellow - the ones over 6.0 are in red.  And a map to go with that list:

Basically for two days there were quite large earthquakes (up to 7.2) in that area which now are called the preshocks of the main one.  It was a rather shallow quake so it caused a huge tsunami.  Basically, the whole pacific ocean is under a tsunami warning.  Waves hitting the nearby shore were said to be up to 10m high.  The Sendai (biggest city in that region ~1 million population) airport was completely flooded.  In Tokyo, the transportation network was stopped and the airports closed.  I guess it is too early to really tell, but the damage of the quake and the tsunami (especially near the epicenter) will be huge.

What is really amazing is how Japan is prepared for such disasters.  The building codes for instance have been quite strict since 20 years ago or so.  Nuclear power stations have automatic shut off switches based on shake sensors (a few went down due to the earthquake).  Even the shinkansen (bullet train) shuts off automatically during an earthquake.  There is also quite advanced infrastructure to combat tsunamis from such events.  If such an earthquake happened in unprepared countries, they would be completely devastated (for instance the much smaller (about 1000 times) 7.0M Haiti earthquake last year).

The only thing I noticed different at home is that my closet door was fully open (I left it slightly open).