posted on Jul, 26 2011 @ 12:27 PM
Originally posted by CynicalWabbit
Yes, my bad on the spelling Yes from what I've read the ground can raise and fall several feet after a large quake, having never been in a large
quake i can't say with absolute certainty.
I wasn't sure about this, but I just watched a special on NatGeo about the 9.5 earthquake off the
coast of Chile, around something like 1960.
It was a similar quake to Fukushima which involved a subduction zone. They had excellent graphics which explains how and why this happens. The closest
analogy would be if you push the edge of a sheet of paper flat on a desk, so it bows up, that's the shape of the continental plate before the
earthquake.
When the earthquake occurs, the stress is relieved. That's equivalent to the sheet of paper flattening out, and since it was bowed up before, that
means it moves down. It makes it look like the land sinks but what really happens it it's restored to its pre-stress level (with the paper on the desk
analogy, the paper is once again flat on the desk). In Chile, the amount of subsidence was 2 meters. That destroyed a lot of very fertile farmland.
If you get a chance to watch the NatGeo special about the 9.5 quake off Chile, watch it. Then you will understand much better what's happening with
the subsidence in Japan, it's the same thing. Here's the link, it's called "Ultimate Earthquake":
channel.nationalgeographic.com...-Videos
edit on 26-7-2011 by Arbitrageur because:
clarification