Posted by u/RobotTimeTraveller 14 hours ago
TIL the 2011 earthquake off the coast of Japan was so powerful - measuring almost 9.0 on the Richter scale - it moved Japan 8 feet closer to North America and shifted the planet on its axis, causing the length of a day to shorten by almost 1.8 microseconds
The boss will make us stay 1.8 microseconds to make it up
"If the earth can move faster, so can you!"
JAPAN IS COMING RIGHT AT US!!!
As someone living in Japan, I'd like it to get as further away from China as possible.
Makes you wonder over billions of years of cataclysms, how much longer or shorter earth days once were.
The moon is pretty cool too. It keeps getting 1.5inches farther away each year. I'd imagine the tides were a lot stronger and the moon appeared way bigger in the sky millions of years ago.
I always thought this [graphic representation ](https://youtu.be/NSBjEvPH2j4) gives an interesting look at it.
That is fascinating and frightening!
A little tidbit I picked up from a Calculus textbook I started reading. The linked article doesn't mention the time difference, so here's a link from the NASA web site: [https://www.nasa.gov/topics/earth/features/japanquake/earth20110314.html](https://www.nasa.gov/topics/earth/features/japanquake/earth20110314.html)
This isn't the first time a massive earthquake has changed the length of Earth's day. Major temblors have shortened day length in the past.
The scenario is similar to that of a figure skater drawing her arms inward during a spin to turn faster on the ice. The closer the mass shift during an earthquake is to the equator, the more it will speed up the spinning Earth.
The 9.1 Sumatra earthquake in 2004 shortened the day by 6.8 microseconds.
I think I read that the Richter scale is no longer used to measure the magnitude of an earthquake
You're right! TIL two new things.
>The Richter scale – also called the Richter magnitude scale or Richter's magnitude scale – is a measure of the strength of earthquakes ... This was later revised and renamed the **local magnitude scale**
[https://en.wikipedia.org/wiki/Richter\_magnitude\_scale](https://en.wikipedia.org/wiki/Richter_magnitude_scale)
So THAT explains why I've been so fucking exhausted for the last decade.
Has it already been a decade? Damn. Time just flies when the days are 1.8 microseconds shorter.
Edit: [If you want to know w]hat an almost 9.0 on the Richter scale feel like? I remember running through a corridor during that earthquake and it felt like [it was moving like] that scene from the movie *Inception*. [Edit: The whole ground moved like a trampoline and it’s weird because you forget that the ground is supposed to be a solid.] I live a little over 200km away from the epicentre. Now, dozens of earthquakes later, I’m blasé to anything less than a 5.0 on the Richter scale.
Idon't know if it helps, but there are videos of a 9 on Youtube:
[https://youtu.be/pJUSbDCc-GE](https://youtu.be/pJUSbDCc-GE)
So did the airlines adjust the prices down accordingly, or are they just pocketing the savings?
The 1.8 microsecond number was a theoretical calculation, not a real measurement. The length of a day (LOD) is measured every day or so(\*), and changes up and down by a few 100 microseconds most of the time. If we had minute by minute measurements, the effect of this earthquake (or any earthquake) would be invisible.Much more significant are things like variations in a hurricane season, or the amount of winter snowfall, or glacier melt. \* Published weekly, with interpolation for sub-daily intervals.
Just curious, how does weather/climate stuff affect the length of our days? this stuff is so interesting to me.
I was stationed on Oahu during this. Tsunami warnings were going off and cops were driving up and down the streets telling everyone to seek higher ground. It was terrifying because I lived on the Gulf Coast of Mississippi during hurricane Katrina and remember seeing how much damage water can do to houses.
TIL: The richter scale is logarithmic. A 9 on the scale is 100x stronger than a 7. Edit: base 32 so it's actually 1000x stronger
It's logarithmic, but not in base 10 but in base ~32. A 9 on the scale is 1000x stronger than a 7.
I can't be the only one who noticed that loss of 1.8 microseconds, It messed up my sleep for weeks.
8 *feet*?? Holy SHIT. It took Pangea millions of years, pretty sure the average continental movement is like 2 inches per year.
I wonder what effect the 1960 Valdivia, Chile earthquake had, which was more than 5 times more powerful measuring 9.5 Richter
The Richter scale isn't used as a large earthquake measuring tool anymore. The correct measuring tool is the "Moment Magnitude" scale. [https://www.usgs.gov/natural-hazards/earthquake-hazards/science/earthquake-magnitude-energy-release-and-shaking-intensity?qt-science\_center\_objects=0#qt-science\_center\_objects](https://www.usgs.gov/natural-hazards/earthquake-hazards/science/earthquake-magnitude-energy-release-and-shaking-intensity?qt-science_center_objects=0#qt-science_center_objects)
I remember hearing that and trying to convince my parents my bedtime should be 1.8 microseconds later because the day was shorter. I thought I was a genius.
So ... airline tickets to Tokyo from the US should be cheaper?
Something people often don't realise about the richter scale is how its exponential power. So a 7 isn't once more powerful than a 6, its 10 times more. The differnce between 7 and 8 is its 32 times more powerful and a scale 9 is 1,089 times stronger than a scale 7.
I suspect that the cause of the planet shifting on its axis is not directly due to the earthquake, but rather due to the shift in mass that resulted from the earthquake. Very interesting!
I'm just going to [leave this here](https://www.youtube.com/watch?v=NSBjEvPH2j4) for anyone interested.
Holy shit
So uh, is anyone going to point out that not all of Japan moved 8 feet? Just the parts closest to the epicenter. Osaka and further south hardly moved at all. [Here's a map](https://www.unavco.org/highlights/2011/M8.9-Japan-images/M8.9-Japan-ARIA_co_and_postseismic_V0.jpg). Or if you want an even higher number, along the actual faulting the horizonal displacement was as high as 20 *meters*. Invasive a huge wall of rock rushing at you from 60 feet away.
Just 555,555.556 more of those and we will shift the length of a day a full second!
TIL that Richter in Richtet scale is from the lastname of the inventor rather the judging or measuring. It’s confuse for me as a German.
Is this why I feel like I haven't gotten enough sleep in 10 years
Japan trying to get away from North Korea.
The flight is 8 feet shorter, but they didn't lower ticket prices any. Damn cheating airlines.
Every time yo momma jumps the same thing happens
So thats their game plan, inch closer and closer to the us to to give another surprise attack? Very sneaky sis.
I thought it felt shorter.
I knew something was off
Well no wonder my sleep patters have been screwed up since then.
And it went on and on, longer than any I had experienced. I thought it was an internal event, some kind of stroke, I just sat on the bed waiting for it to pass, then I noticed some things in the room moving. This from hundreds (a thousand?) kilometers away.
I was living in Hilo and we were pretty scared of a Tsunami. I worked at a bar 1 block from Hilo Bay at about 3 inches elevation. We got a call about 9:30 that Japan was hit. We packed up the downstairs of the bar and moved what we could upstairs. Rhonda the owner says, ok well, why doesn't everyone take a few bottles for the night, as I'm not sure there will be any bar here in the morning. Hilo ended up being fine, Kona had a good bit of surge, knocked a house off it's moorings and was floating in Kealakekua bay.
Imagine being a software developer for GPS mapping stuff. The product has pretty great precision. Then, after this, all the coordinates are suddenly off by more than 2M. Probably rotated a bit, too.
I was on a flight from SFO to Australia. Thought it was quicker than expected.
Weird to think about a whole country moving 8 feet to the right
The interesting thing to me about this is it probably means we had a much longer day millennia ago but subsequent large quakes could have shortened it also
How many feet away is Japan and how do I force some of these earthquakes
Makes you wonder over billions of years of cataclysms, how much longer or shorter earth days once were.
Wait...how does this shorten the length of a day? I'm not a huge science person so I don't understand... I thought the planet rotating as it revolves around the sun causes the day/night cycle...how can an earthquake effect that?
Do you mean Japan’s closest point? Or an average in the change in distance? Or *all* of Japan moved 8 feet closer?
So we just have a couple thousand more of those babies and we can move earth a little further from the sun and climate chang is cured!! Is that how this works?
Axis is the tilt of earths rotation not the orbit around the sun.