This is a good opportunity so I'm gonna post what I, a native-born Japanese, have been always thinking: This country is literally shaped by earthquakes. This is true not only in a geological sense but it also applies to the culture. Earthquakes affect how all the buildings here are made, the way of transportation, and virtually every aspect of our daily life. We always fear them and talk about them, but we're kinda resigned to accept the fate. This concept of resignation is seen in many ways in the Japanese culture. But it's also earthquakes that make us truly united. I realized this when the big quake hit the country five years ago. As much as we hate them, we are defined by earthquakes.
Accroding to the USGS's page (linked to by civilian), the earthquake was a strike-slip earthquake, where two blocks of crust slide laterally relative to eachother on a vertical fault, with no real uplift of subsidence of the seafloor. It's unlikely that there will be a major tsunami, as these are caused by rapid displacement of lots of water by the seafloor. However, given the right topography along the fault, it is possible.
I was in Tokyo at my hotel when it happened. I thought maybe I had a Japanese vibrating bed for an alarm clock before realizing what was happening. I was on the 7th floor of a hotel and there was a slight sway for about 45 seconds. Given the duration I assumed it was fairly sizeabke but far away.
Apparently not a threat to Hawaii - Tsunami threat for Japan:<p><a href="http://ptwc.weather.gov/text.php?id=hawaii.TIBHWX.2016.11.21.2109" rel="nofollow">http://ptwc.weather.gov/text.php?id=hawaii.TIBHWX.2016.11.21...</a><p>"THE PACIFIC TSUNAMI WARNING CENTER HAS ISSUED A TSUNAMI THREAT MESSAGE FOR OTHER PARTS OF THE PACIFIC LOCATED CLOSER TO THE EARTHQUAKE. HOWEVER... BASED ON ALL AVAILABLE DATA THERE IS NO TSUNAMI THREAT TO HAWAII."
Live stream: <a href="http://www3.nhk.or.jp/nhkworld/en/live/" rel="nofollow">http://www3.nhk.or.jp/nhkworld/en/live/</a>
USGS map: <a href="http://earthquake.usgs.gov/earthquakes/eventpage/us10007b88#map" rel="nofollow">http://earthquake.usgs.gov/earthquakes/eventpage/us10007b88#...</a><p>//edit Any idea when the tsunami will hit? The original news happened at 20:59 UTC (1pm PST), but I'm not sure how fast tsunamis travel.<p>A sister comment referenced tsunami.gov, which is for US dwellers, but this NOAA website has more information for people living outside the US:
<a href="http://ptwc.weather.gov/?region=1&id=pacific.TSUPAC.2016.11.21.2129" rel="nofollow">http://ptwc.weather.gov/?region=1&id=pacific.TSUPAC.2016.11....</a><p>text: <a href="http://ptwc.weather.gov/text.php?id=pacific.TSUPAC.2016.11.21.2129" rel="nofollow">http://ptwc.weather.gov/text.php?id=pacific.TSUPAC.2016.11.2...</a><p><pre><code> ESTIMATED TIMES OF ARRIVAL
--------------------------
* ESTIMATED TIMES OF ARRIVAL -ETA- OF THE INITIAL TSUNAMI WAVE
FOR PLACES WITHIN THREATENED REGIONS ARE GIVEN BELOW. ACTUAL
ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE
LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN
WAVES CAN BE FIVE MINUTES TO ONE HOUR.
LOCATION REGION COORDINATES ETA(UTC)
------------------------------------------------------------
KATSUURA JAPAN 35.1N 140.3E 2150 11/21
KUSHIRO JAPAN 42.9N 144.3E 2217 11/21
HACHINOHE JAPAN 40.5N 141.5E 2236 11/21
SHIMIZU JAPAN 32.8N 133.0E 2312 11/21
NOBEOKA JAPAN 32.5N 131.8E 2319 11/21
</code></pre>
So, Katsuura was just hit, and the other cities will be hit soon.
Worryingly, TEPCO is reporting that the cooling system for the 3rd reactor at Fukushima Daiichi has stopped (via the NHK live TV stream)... Supposedly there is enough water in the pool that it will not be dangerous for quite awhile, but this needs to get fixed soon.
The livestream is talking about how 2 methods of water cooling at the Fukushima power plant, but there's no immediate danger because of some third system. Anybody have more details on this?<p>"Right now the water temperature is 27 degrees and the water temperature will not rise to dangerous levels... for a while."
I have a Japanese friend who said whenever a quake in NZ hits, the whole of Japan is on edge for the next month because Japan quakes often follow NZ quakes after a couple of weeks.<p>It seems to have happened again. I wonder why you don't hear anything in scientific circles about this.
Everytime something important happens I notice reddit is a better source of getting an aggregate of information than twitter or (sometimes) news outlets.<p>Relevant reddit thread for this incident.<p><a href="https://www.reddit.com/r/worldnews/comments/5e6jzt/73_magnitude_earthquake_hits_fukushima_japan_3/" rel="nofollow">https://www.reddit.com/r/worldnews/comments/5e6jzt/73_magnit...</a><p>Also, /u/TheEarthquakeGuy should be posting soon.
I was woken up by the quake this morning. Pretty strong feeling; it shook for a good few minutes. As far as I can tell everyone's safe in Tokyo, though the trains are a bit delayed and the elevators in my building weren't running.<p>Stronger by far than any quake I've ever felt in 8 years in San Francisco.
Tsunami alerts/forecasts:
<a href="http://typhoon.yahoo.co.jp/weather/jp/tsunami/" rel="nofollow">http://typhoon.yahoo.co.jp/weather/jp/tsunami/</a><p>They should really provide an English version of this page. Come on, Yahoo Japan.
Reading the news article, it says that the waves are about 1m in height, some are about 60cm in height. How do they distinguish that these waves are caused by the earthquake and not waves created by other causes (ocean currents, wind etc)?