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Liquefaction from the Sendai earthquake – a remarkable video
- wmwong 16y agoFor those of us who are not familiar with the term liquefaction. In simple terms, I think it means the soil becomes like quick sand because of the earthquake. http://en.wikipedia.org/wiki/Earthquake_liquefaction http://en.wikipedia.org/wiki/Earthquake_liquefaction
- michaelcampbell 16y agoExactly. Liquefaction is not water coming up from the ground, although that's a side effect of it.
- martinkallstrom 16y agoEven more startling is the liquefaction happening in Christchurch: http://www.youtube.com/watch?v=2WoKu5VxKgs http://www.youtube.com/watch?v=2WoKu5VxKgs Here is an awesome video by a Christchurcher showing how the sediments pouring up through earthquake cracks have the perfect mixture of water and soil to be prone to liquefaction: http://www.youtube.com/watch?v=1KqlAMWMjOE http://www.youtube.com/watch?v=1KqlAMWMjOE
- NZ_Matt 16y agoI spent a week clearing this crap out of people back yards with the student army of volunteers. They estimate 200000 tonnes of the silt had to be cleared. Here's an example of the silt coming out of the ground minutes after the quake. http://www.youtube.com/watch?v=e_twYpUJl9o http://www.youtube.com/watch?v=e_twYpUJl9o And here's a good explanation http://mandenomusings.wordpress.com/2011/03/03/christchurch-earthquake-liquefaction-explained/ http://mandenomusings.wordpress.com/2011/03/03/christchurch-...
- aaronbrethorst 16y agoThat is really disturbing, and it reminds me of something I just read the other day. For any Seattle startup folks, just remember that all of Pioneer Square (and then some...) is a liquefaction zone[1]. Also, don't forget that the Viaduct is a death trap, and you really are better off never setting foot (or wheel, I guess) on it. [1] http://www.thestranger.com/slog/archives/2011/03/16/more-seattle-quake-stuff http://www.thestranger.com/slog/archives/2011/03/16/more-sea...
- jarin 16y agoYou should also stay in an underground bunker and never go outside, because dude do you have any idea how many asteroids are out there?? The entire surface of the Earth is an Asteroid Impact Zone!
- aaronbrethorst 16y agoor just stay off the viaduct. that seems far more straightforward :)
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- stevenbedrick 16y agoYeah, avoiding the viaduct has always struck me as a sensible precaution.
- InclinedPlane 16y agoThe 520 bridge is also very vulnerable to earthquakes (the primary reason why it's being replaced).
- sukuriant 16y agoYou mean that bridge that's about a foot above the water level and, when there's a really turbulent storm, can have rough water on one side and calm water on the other, and have waves literally crashing over the cars from the one side of the water? Nooo, I would have never thought that bridge would be dangerous in an earthquake! </sarcasm> I'm not intending to mock you, though it's probably coming off that way. Outside of the cool special effects during a storm (seriously, the 'rough water, bridge, calm water' effect is quite eerie), I have no idea why that bridge was built the way it was.
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- malesniak 16y agoQuite a remarkable video... a little less so when you get to the end and he informs you of the history of Tokyo Central Park (reclaimed land). Still... unbelievable. Much less dramatic that the Google images of entire communities washed from the Earth... devastating.
- dstein 16y agoThat's the most casual walk through a Japanese park during an earthquake I can imagine.
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- BasDirks 16y ago"a sombrero, and a huge clock" Is this Chuck Norris wielding the camera?
- delinka 16y agoI've never experienced an earthquake. As such, the cracks and drifting earth make me doubt the reality of such a video. Does this drifting actually occur at the surface like that? Edit: speeling ;-)
- michaelcampbell 16y agoI've been in 2 about 20 years ago; both ~5.1. If memory serves there were 2 distict types of shaking. The first was a fairly high frequency vibration that shook the walls and mimic what you see in movies; $#@! flying off shelves, etc. The second came a few seconds later, and was a slow back and forth horizontal movement of the ground. I remember it being a bit faster frequency than that video shows, maybe about 1Hz, but it seemed like the ground was just moving fairly slowly back and forth a few inches.
- delinka 16y agoI've heard many accounts of these phenomena from others. What I'm having difficulty with is the relative motion of the different pieces of earth. I live on pretty solid ground away from active fault lines. If one of our minor fault lines ever acted up, I could certainly imagine the kind of motion you mention. But if my property "cracked," I'd expect to feel the swaying motion and that each piece of my yard would move in the same direction preventing me seeing the motion. On further consideration that the park in the video is built on a former bay, I supposed the quake could be making the dirt float around on the mushy underside. The first thing I noticed was an oddness about the crack in the sidewalk. It seems to have cracked perfectly along some crack line that's outside of the sidewalk (not likely - just because dirt cracks underneath doesn't mean the concrete will crack exactly where the dirt does) and there seems to be some rubbery surface where the crack ends in the sidewalk (it stretches as the parts of earth move in different directions.) Not like the pure concrete sidewalks I'm accustomed to, but Tokyo is worlds away and maybe it's not just concrete. P.S. Why the downvoting on my original post? Is it not a valid question?
- chronomex 16y agoThat pavement is most likely asphaltic concrete (commonly, though incorrectly, known as "asphalt"), which is a mixture of asphalt and sand/gravel aggregate. It's fairly flexible, at least compared to Portland cement concrete.
- kazuya 16y agoI've been in Tokyo for more than 20 years but I cannot tell which 'Central Park' this is. Shinjuku Central Park is a well known one and it is surrounded by skyscrapers, but this one doesn't have them. Any hints?
- rheide 16y agoI think it might be near Odaiba.
- brianbreslin 16y agohe says it is in reclaimed part of tokyo bay. so wouldn't have skyscrapers ALL around, but should have some in a few of the shots.
- kazuya 16y agoAh I didn't notice it as I turned audio off. Now I managed to spot it. The park is actually Makuhari Kaihin Park (幕張海浜公園) in Chiba, not in Tokyo (that's why I was not aware of it). And yes it is on reclaimed land, the homepage of the park in fact mentions liquefaction.