Friday Afternoon Videos
Rob Long ·
Mar 18, 2011 at 2:27pm
Amazing footage from the Japanese earthquake. Almost unbelievable. From the Landslide blog of the American Geophysical Union. (Yes, I am a geek.)
Worth watching. And keep watching, about halfway through, to see what experts mean when they refer to "liquefaction."
I remember back in 1994, during the big Northridge earthquake, I was living on the beach in Santa Monica -- which was hard hit by that 6.1 shaker -- and as all of my neighbors gathered on the street at 5AM, waiting for the power to come back on and for the aftershocks to stop, we all worried about liquefaction.
I had no idea what it was. Until I watched the video above. Glad I didn't know.
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Comments :
May '10
Re: Friday Afternoon Videos
Amazing. I've never seen a video like this. Thanks.
Jul '10
Re: Friday Afternoon Videos
I'm curious as to where in Tokyo he was. He mentioned that he's on reclaimed land, so I'm guessing he meant Odaiba. However, what most don't realize is that most of what now makes up central Tokyo is on reclaimed land. It's just that the earliest reclamation projects were so long ago that their memory is no longer in the public consciousness. I wonder if the effects were only this severe because he was standing on land reclaimed only about 20 years ago?
Dec '10
Re: Friday Afternoon Videos
Cool! Well, if it's somebody elses's house foundation, or whatever, cool!
Feb '11
Re: Friday Afternoon Videos
I am amazed at the calmness in this guys voice. Just another walk in the park I guess.
May '10
Re: Friday Afternoon Videos
So, what is liquidifcation? Groundwater? Pipes?
Oct '10
Re: Friday Afternoon Videos
Finster - that is what I was thinking. I would have been running like made.
ParisParamus - I believe liquefaction occurs when the ground (soil, dirt) is shaken and turns into basically liquid. That isn't quite what seems to be happening in the video though. This looks more like sea water oozing and shooting up through the ground as it breaks apart.
Nov '10
Re: Friday Afternoon Videos
That's pretty trippy. Kinda something I've wanted to experience - an earthquake while outside, to see what happens. I've been inside for every earthquake I've ever been in.
Xty:
ParisParamus - I believe liquefaction occurs when the ground (soil, dirt) is shaken and turns into basically liquid.
This is essentially correct, but also add water. Teh Wiki has a good article up.
Jul '10
Re: Friday Afternoon Videos
".... making Me kinda nervous... "
Kinda?!
That's pretty cool to witness.... from Here.
Jun '10
Re: Friday Afternoon Videos
As we say in Boston- that was wicked pissah!
Jun '10
Re: Friday Afternoon Videos
I'm not sure how apt this analogy is, but consider a boat sailing through water. What you see is that water has a buoyancy that allows the ship, because of hull design, to float. If you inject a massive quantity of air rising from the bottom of the ocean, which might result from volcanic action, the water loses buoyancy and cannot hold the same weight and the ship sinks. To extend the analogy to soil, water is introduced into compacted soil (soil under load) through agitation (earthquake). When that happens and the agitation ceases, the load again exerts pressure on the now water impregnated soil forcing the water in that soil to move from the high pressure area to a low pressure area (think squeezing a sponge). It is this movement of water from high to low pressure that I believe is referred to as liquefaction. The introduction of water into soil causes the soil to lose its bearing capacity in the same way aerated water loses buoyancy. I'm not an engineer, so if this post needs correction I will gladly yield to any that can provide a better explanation and/or analogy.
Dec '10
Re: Friday Afternoon Videos
That was a fantastic first person account! In light of the devastation we've seen happening just north of there at that time, however, it is horrifying to think of how awful it must have been for those living there. Seeing the ground wave & sway like that is just awesome. For allegedly right-thinking people to suppose tiny mortals could damage a planet that can do THAT is beyond delusional.
Sep '10
Re: Friday Afternoon Videos
Cas Balicki has a learned explanation. Here's one that even I can understand--when I was a kid and my parents took me to the beach, I would stomp with my bare feet on the wet sand and watch, fascinated, as my footprint filled up with water--even though the ocean was some distance away. That's liquefaction. What my feet did to a tiny area is what the earthquake was doing to that park, sort of.
May '10
Re: Friday Afternoon Videos
If I had been there, I wouldn't have been so calm. I'd have liquefaction in my pants.
May '10
Re: Friday Afternoon Videos
"Quite a few people in the park; they're not running away..." TO GO WHERE???
I've never experienced a quake at all, but the fear of one of those cracks opening up and taking me, or of a sinkhole suddenly appearing is about as scary as scary gets.
Edited on Mar 18, 2011 at 8:37pmAug '10
Re: Friday Afternoon Videos
Liquifaction was one of the reasons the 1989 quake was so devastating to certain parts of San Francisco.
May '10
Re: Friday Afternoon Videos
If you read the comments in the link, it's not clear that the water appearing is liquefacton. What it may be is the nearby bay/ocean water being propelled in and up on the reclaimed land.
Aug '10
Re: Friday Afternoon Videos
Which is the definition of Liquefaction. http://en.wikipedia.org/wiki/Soil_liquefaction
It was the Marina district of San Francisco -- landfill dumped into the Bay to make land -- that suffered in 89. The effect was liquefaction.