# Large earthquake in Northeast Japan **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 11, 2011, 6:10am UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279 "2011-03-11T06:10:53Z")\ **Posts on this page:** 20\ **Page:** 10
**Author:** ![rocking\_chair](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rocking_chair/32/2918_2.png) [@rocking\_chair](https://boards.straightdope.com/u/rocking_chair)\ **Post date:** [March 11, 2011, 8:37pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/181 "2011-03-11T20:37:21Z")
they are reporting that the tsunami moved water 3 miles in. it would be very difficult to move large numbers of people out of the way of that even with a 20-30 minute head start on the wave. crescent city is reporting one person missing. cnn just reported 4 trains are missing. 4 trains, good heavens… ---
**Author:** ![Oakminster](https://avatars.discourse-cdn.com/v4/letter/o/77aa72/32.png) [@Oakminster](https://boards.straightdope.com/u/Oakminster)\ **Post date:** [March 11, 2011, 8:41pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/182 "2011-03-11T20:41:42Z")
> [@Kyla](#): > > It’s unkind of me to think negatively of someone in a tragic situation, but seriously? What kind of fucking moron are you? :rolleyes: A Darwin Award nominee. ---
**Author:** ![The\_Devil\_s\_Grandmother](https://avatars.discourse-cdn.com/v4/letter/t/74df32/32.png) [@The\_Devil\_s\_Grandmother](https://boards.straightdope.com/u/The_Devil_s_Grandmother)\ **Post date:** [March 11, 2011, 8:45pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/183 "2011-03-11T20:45:52Z")
> [@Sunspace](#): > > Cripes. Looking at the USGS site, how many of those aftershocks were major earthquakes in themselves? Is a 6 considered a major earthquake? Yes, a 6 is a pretty darn good shake. The last quake I was in was a 4.6 and it was enough to startle me and push things off the shelves. I was in a post-earthquake-upgrades-to-the-building-codes house in Southern California at the time. For comparison, the Loma Prieta earthquake that shook down the Bay bridge was a 6.9. The [Richter magnitude scale](http://en.wikipedia.org/wiki/Richter_magnitude_scale)used to describe earthquakes calls an 8.9 quake a “great” quake. I can’t imagine how frightening it must have been. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 11, 2011, 8:55pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/184 "2011-03-11T20:55:34Z")
> [@The\_Devil\_s\_Grandmother](#): > > The [Richter magnitude scale](http://en.wikipedia.org/wiki/Richter_magnitude_scale)used to describe earthquakes calls an 8.9 quake a “great” quake. I can’t imagine how frightening it must have been. Was this 8.9 on the Richter scale or the Moment Magnitude Scale? ---
**Author:** ![Yorikke](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yorikke/32/4335_2.png) [@Yorikke](https://boards.straightdope.com/u/Yorikke)\ **Post date:** [March 11, 2011, 8:55pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/185 "2011-03-11T20:55:48Z")
Yes, the news here (San Fran) os reporting one death in Crescent City. I live about a quarter mile from Ocean Beach, right where the tsunami would have a field day (we have “tsunami escape route” signs on our street), and it was pretty much a non-starter. Surges approximating high tide. ETA : They reported 8-foot waves in Crescent City. Couldn’t’ve been more than 18 inches in SF. Joe ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [March 11, 2011, 8:59pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/186 "2011-03-11T20:59:27Z")
If you look at the habor at [Crescent City](http://en.wikipedia.org/wiki/Crescent_City,_California) you can see how a big wave would cause damage there, due to its shape ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [March 11, 2011, 9:06pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/187 "2011-03-11T21:06:53Z")
> [@wheresgeorge04](#): > > I live about a quarter mile from Ocean Beach, right where the tsunami would have a field day (we have “tsunami escape route” signs on our street), and it was pretty much a non-starter. Surges approximating high tide. That’s good. I have friends there that I’m worried about. One in Seattle too. ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [March 11, 2011, 9:06pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/188 "2011-03-11T21:06:55Z")
> [@rocking\_chair](#): > > they are reporting that the tsunami moved water 3 miles in. it would be very difficult to move large numbers of people out of the way of that even with a 20-30 minute head start on the wave. All the tsunami evacuation routes in the areas I’ve been that were affected by the Indian Ocean one don’t seek to move large numbers of people away from the shoreline - just up the nearest hill. Of course the nearest hill may be a long way inland, looking at the images of Japan, but not always. ---
**Author:** ![Sakuma\_Drops](https://avatars.discourse-cdn.com/v4/letter/s/50afbb/32.png) [@Sakuma\_Drops](https://boards.straightdope.com/u/Sakuma_Drops)\ **Post date:** [March 11, 2011, 9:15pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/189 "2011-03-11T21:15:44Z")
> [@Mahaloth](#): > > Was this 8.9 on the Richter scale or the Moment Magnitude Scale? [Moment magnitude.](http://en.wikipedia.org/wiki/Moment_magnitude_scale) All earthquakes over 7.0 in intensity (the two scales are roughly equal at that magnitude) are measure by moment magnitude, which is better suited for the much larger energy releases at that intensity. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 11, 2011, 9:19pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/190 "2011-03-11T21:19:36Z")
> [@Sakuma\_Drops](#): > > [Moment magnitude.](http://en.wikipedia.org/wiki/Moment_magnitude_scale) All earthquakes over 7.0 in intensity (the two scales are roughly equal at that magnitude) are measure by moment magnitude, which is better suited for the much larger energy releases at that intensity. That’s what I figured. I haven’t heard anyone use the Richter scale for a major earthquake in a long while and did not know which was being referred to. ---
**Author:** ![rocking\_chair](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rocking_chair/32/2918_2.png) [@rocking\_chair](https://boards.straightdope.com/u/rocking_chair)\ **Post date:** [March 11, 2011, 9:20pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/191 "2011-03-11T21:20:37Z")
poking around the web has the quake hitting at 2:46 jst and the sendai airport being hit by the water at 3:55 jst. there are about 1 million people in the city. the water moved 10km into the city from the coast. the tsunami alert was issued immediatly. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [March 11, 2011, 9:24pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/192 "2011-03-11T21:24:30Z")
> [@tdn](#): > > That’s good. I have friends there that I’m worried about. One in Seattle too. Not much danger here - though most people are smart enough to stay away from the water. [Here](http://sanfrancisco.cbslocal.com/2011/03/11/tsunami-watch-for-california-coast-after-big-japan-quake/) is the KCBS summary including video of a boat sinking in Santa Cruz harbor. When I was driving to work about 8:30 am local time they were reporting that chunks of some piers were being torn away. Luckily for us, the tide was out when the tsunami hit which helped a lot. However the dreadful nature of the quake is obvious considering its power 6,000 miles away. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 11, 2011, 9:31pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/193 "2011-03-11T21:31:13Z")
By the way, does anyone know what this earthquake would read on the Richter scale? I’m curious, now. ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [March 11, 2011, 9:34pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/194 "2011-03-11T21:34:23Z")
> [@Voyager](#): > > Not much danger here - though most people are smart enough to stay away from the water. That’s good to know. But yeah, that’s a lot of power! ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [March 11, 2011, 9:40pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/195 "2011-03-11T21:40:20Z")
> [@tdn](#): > > That’s good to know. But yeah, that’s a lot of power! National Geographic estimates the energy released by the 9.2 Indian Ocean earthquake to be equivalent to 23,000 Hiroshima bombs, though other estimates have gone up to 80,000 times greater than Hiroshima. I don’t know enough about moment magnitude to know how that translates into the amount of energy released by an 8.8 quake - or if they’re are other factors that increase or decrease it. But when a tsunami of such a scale makes landfall, it is merely a transference of a tiny proportion of that energy. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [March 11, 2011, 9:43pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/196 "2011-03-11T21:43:38Z")
Did I really hear a geologist on NPR saying that they estimate as much as 50 feet of sudden plate movement? That’s incredible. ---
**Author:** ![Hal\_Briston](https://avatars.discourse-cdn.com/v4/letter/h/a9a28c/32.png) [@Hal\_Briston](https://boards.straightdope.com/u/Hal_Briston)\ **Post date:** [March 11, 2011, 9:53pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/197 "2011-03-11T21:53:27Z")
> [@Annie-Xmas](#): > > Pity it took this to get Sheen and Lohan off the front page Pity a lot of people are still fucking morons. From the New York Post site: > [@](#): > > MOST POPULAR STORIES: > 1: Los Angeles police seize ‘antique’ weapon and bullets from Charlie Sheen’s Sherman Oaks house in wea > 2: 8.9 Earthquake Hits Japan ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [March 11, 2011, 9:54pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/198 "2011-03-11T21:54:03Z")
Wow to both posts. ---
**Author:** ![Hal\_Briston](https://avatars.discourse-cdn.com/v4/letter/h/a9a28c/32.png) [@Hal\_Briston](https://boards.straightdope.com/u/Hal_Briston)\ **Post date:** [March 11, 2011, 9:54pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/199 "2011-03-11T21:54:32Z")
> [@jjimm](#): > > Getting pissed off with the so-called “experts” on the BBC. > \ > Dipshits. They’re no better on CNN. One of their vapid talking heads gave this brilliant bit this morning: “…which is 400 kilometers from the epicenter. That’s nearly _fifty miles_.” Yeah, you’re only off by about 200 miles. And nothing new on **Auto** ’s facebook. ---
**Author:** ![Yeticus\_Rex](https://avatars.discourse-cdn.com/v4/letter/y/a698b9/32.png) [@Yeticus\_Rex](https://boards.straightdope.com/u/Yeticus_Rex)\ **Post date:** [March 11, 2011, 10:12pm UTC](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279/200 "2011-03-11T22:12:20Z")
> [@user\_hostile](#): > > Yeah, I should added a fudge factor for that, but I know nothing about the littoral dynamics of tsunamis. Would it really delay it that much? It really depends on how much distance was deep water and how much was shallow water between the epicenter and the coast. Speed = sqaure root of (g\*d), where g is the gravity constant 9.81m/s(squared) and d is depth of ocean. [Probably the best explanation of tsunami speed that I have seen.](http://plus.maths.org/content/tsunami-1) Warning: [Multiple physics equations ahead.](http://oceanworld.tamu.edu/resources/ocng_textbook/chapter16/chapter16_01.htm) [Previous page](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279.md?page=9) [Next page](https://boards.straightdope.com/t/large-earthquake-in-northeast-japan/574279.md?page=11)