reply to post by Olivine
Thanks for your comments, Olivine.
Things have been a bit quiet lately. I must admit that I haven't been posting much or even studying the daily quake info as intently as I normally
would. It's a busy time of year in my work at present, but even allowing for that I have found it hard to focus on the subject and dig deep for
data.
All the same I've been keeping an eye on things and I'd like to make a few comments about the current situation and what could be coming up soon.
One thing that's bothering me right now is that it's been quite a while since the last mag 7 or bigger quake. In fact the last mag 7 was a 7.0 in the
Gulf of California on April 12, just one day after the April 11 mag 8.4 and 8.0 events off Sumatra.
Weird, that. Two very powerful events off Sumatra (a pair of mag 8s in the same region on the same day is very, very rare indeed), then one day later
a pretty solid bump down in the Gulf of Cali and then -- not a heck of a lot. Okay, there have been some mag 6-range quakes but no 7s. For about six
weeks. Seeing as we average about 18 of them a year that's a fair break.
This has been discussed a bit over on the quakewatch thread (where I still lurk almost daily even if I don't post often). I think the consensus is
that there is no particular "reason" why it's been so quiet lately; it's just the way our planet is sometimes.
All the same, I don't like it being so quiet. Unless something very odd has happened without our noticing, energy is still building up on fault lines
all over the place at the same sort of rate it normally does, but not a whole lot is happening to release energy buildups quake-wise. Plenty of little
quakes, sure. But one mag 7.0 is 100 times bigger than a mag 5.0 and it releases 1,000 times more energy. And that's what I'm talking about, because
we haven't had a massive uptick in smallish quakes to "balance out" the energy of a couple of big ones.
Yes, where they had the two mag 8s, a lot of energy got released. Like, the equivalent of many tens of thousands of mag 5 quakes. (And no, I'm not
exaggerating.) But that's a highly active area, with pretty fast-moving plates (up to 20 cm/year versus 5 cm/year for lots of other places), so they
get more of the big events.
Leaving aside Sumatra and that region in general, it's been a little below average elsewhere. True, short-term statistics are problematic. I'm just
making a slightly less than scientific observation. In other words, I'm going with my gut.
Now, while my gut says this current quiet certainly doesn't have to imply some kind of "calm before the storm" situation -- meaning it's not like
everything has to suddenly all let go at once with mag 8 quakes hither and yon -- it's not unreasonable to expect there will be some activity a bit
above the average before too long. A pretty big mag 7 would not surprise me in the least.
But the problem is: where?
Based on historical data alone, the
possible locations would make a very long list! So instead, I'm just going to list a few that I feel are
likely, and some don't even follow that data so closely anyway.
First: Peru. This has bothered me for a while. They had a decent-sized mag 6 there a couple weeks back but I'm still leery of it. I just feel it's
been rather long since a bigger shaker there by the coastal regions. (Southern Peru more likely than the north.)
Second: I see the eastern border of the Tibetan Autonomous Region as a likely candidate for a destructive event. A mag 7 there is historically
very unlikely but even a mid-range 6 could be quite serious.
Third: southern Italy, down near Messina. It's been over 100 years since the
Messina Quake
and tsunami of 1908 -- and that was a mag 7.2 event. I feel that the region could be building up to another. I know there was a tragic quake in
the north of Italy but that's a different fault region entirely.
Fourth: Turkey, especially close to Istanbul. Again, it's been a long time.
Fifth and probably least likely: off Portugal. There's a subsea fault capable of very powerful jolts and it's been pretty quiet for a couple of
centuries now.
None of the above are what I'd define as predictions. When I make predictions I give locations, time frames (within a matter of days), and likely
magnitude. I cannot define the time frames here well enough but I want you all to know that these are the regions I am most concerned about right now.
Yes, I'm concerned about the CSZ in the US Pacific Northwest, but I'm
always concerned about that one as its destructive potential is
horrendous.
So, what I've stated above is just to let you know where I'm watching most closely. Some other regions might be statistically more likely (eg Chile
and of course Taiwan, Indonesia and the surrounding regions), but this is about what I feel, not what the stats say.
Best regards to everyone,
Mike
edit on 25/5/12 by JustMike because: added linky