Can We Escape the Million-Death Earthquake?

I think the thing that?s most interesting at the moment, certainly from my point of view, is looking at the patterns of earthquakes and trying to understand how they operate. This goes some way toward preventing the problem of rogue earthquakes that we talked about earlier.

For example, one thing that was not really understood some years ago but is now becoming more and more established is that earthquakes tend to happen in clusters. You can look at a particular area and see a pattern whereby you get a number of strong earthquakes in a relatively short period of time, and there?s a long gap before the next one. So when you?re trying to assess what?s going to be the future in that particular place, it depends rather on whether you are in the middle of a cluster. In that case it?s a short time interval, or if you?ve reached the end of a cluster, it?s going to be a long time before the next one is due.

Whether you can actually take advantage of that is another matter. It would be rather dangerous to say, "I?m out of a cluster now and I don?t have to worry about earthquake," because you might find that you are wrong. But from that sort of observation we might be able to gradually put together a better idea of why earthquakes happen in the patterns that they do. There?s a lot we still don?t understand about the mechanics of earthquakes.

Another thing that has been discovered within the last 20 years or so: When the rocks actually break in an earthquake, it was formerly thought that it was a clean break?you have a fracture that starts and goes from one end of the fault to the other. What we?ve now discovered?and this has only been possible because of much more sensitive monitoring of earthquakes in the past couple of decades?is that even large earthquakes start off as small ones. You get a very small earthquake in the first second or even fraction of a second in which an earthquake happens, and that triggers a slightly bigger earthquake, which triggers a slightly bigger earthquake, and then suddenly the fault goes bang and the whole fault just unzips. What we don?t know at all is why it happens like that and what tells a fault whether it?s about to have a small or a big earthquake. In a way [that] one seismologist put it recently, we know roughly why earthquakes start, but we don?t know why they stop. What is it that stops a small one from growing into a big one in some cases, and why in other cases does it turn into a really big one?

Source: http://www.popularmechanics.com/science/environment/natural-disasters/can-we-escape-the-million-death-earthquake-13780229?src=rss

daylight savings time john mccain game changer selection sunday corned beef recipe time change daylight savings