Originally posted by kattraxx
reply to post by JustMike
JustMike, did you have any precursors? I'm going to guess no. I notice the depth of the 4.0 mag is that strange exact 10 km we see so often. Is
this some kind of default depth they use, or what?
If you can find out more regarding the scientists telling the people that the tremors should last about a week, let us know. I find that fascinating
and perplexing. I'm also intrigued by their statement relating the seismic activity to the movement of magma. Please do keep us posted on anything
you discover.
Hi again,
I am not sure if I had any precursors. I know that might sound odd but I was feeling off-color for a few days and now I'm better; hard to say if
it's related to this local seismic activity because such events here are comparatively rare.
The 10 km depth in this case doesn't seem to be just a "default depth" as is commonly the case with many USGS reports. I found an extract of the
report about the magma research/hypothesis that gives a bit of info about this:
Magma Intrusions and Earthquake Swarm Occurrence in the Western Part of the Bohemian
Massif
I can't access the whole article as it's on a member (fee-paying) basis, but I'll check around among some people I know and see if anyone can get a
copy through a "free" source.
Regarding the statement that tremors could last up to a week (or even weeks), I got that from
this news report. The
headline reads VIDEO: Treti otres pod Chebskem mel 4 stupne Richtera, byl citit i v Praze.
Translation: Video: Third quake beneath Cheb had a 4 on the Richter scale, was even felt in Prague.
(Please note that I’m posting the Czech text without using Czech characters, because if you don’t have them loaded in your fonts it’ll look very
weird.)
If you watch the video, there’ll be a ten-second ad before the news report starts. Just let it run.
The report itself basically informs us that
there has been some minor damage and that local people are worried. It ends by saying that scientists warn there could easily be a mag 5 in the
region. However, this statement is journalistic license and goes against what the scientists actually say. They mostly consider that while a mag 5
might occur one of these days it’s about the upper limit, so there’s no way that the journo describing it as “easily” is near the mark.
Possible? Yes. Even higher is
possible. But we all know how the news reporting game works…
For our research purposes, though, the key statement in the text on that page (ie below the video) was made by Alena Bouskova from the Bureau of
Geophysics at the Czech Academy of Sciences:
"Seismicka aktivita bude urcite pokracovat," uvedla Bouskove. "Urcite v radu dnu a nelze vyloucit, ze i tydnu," dodala.
Translation: “Seismic activity will definitely continue,” Bouskova advised. “Certainly for several days, and it cannot be ruled out that it will
even be for weeks.”
Note that she is only stating what
could be. It doesn’t have to continue for weeks. However, as the historical evidence shows that quake
swarms tend to hit this area in roughly ten-year cycles and it’s been about 8 ½ years since the last swarm, the possibility of another swarm
beginning is certainly reasonable. Here’s an article in not-too-awful English that gives a little more info:
Czech Republic hit by strongest earthquake since 1986
Mike
Edited to fix a link and some typos. If the edit works...
[edit on 12/10/08 by JustMike]