reply to post by lasertaglover
Hi Laser,
re your query/comment about the quake in Romania. They're not exactly an everyday event there, but the region is quite seismically active and they've
had some very strong quakes in the past, some of them well up in the mag 7 (Mw) range. Today's quake (UTC time) is listed on
EMSC as a mag 3.8 (ML), so nothing to worry about compared to what they've
known even in fairly recent history.
(Note: that link will probably go dead within about a week, but if anyone wants to check the listings later they can go to the
EMSC Home Page which includes updated listings and also a current quake map.)
If you follow the EMSC link in my first paragraph then click on "Maps", then on the new page click on "Seismicity" you'll see how active the region
has been over the years. Also, on the Wiki, there's quite a good summary of
Romania's
larger quake events during the past 500 years or so, along with a list of the more notable quakes in the 21st century -- the largest being a mag
6.0 Mw on Oct 27, 2004.
Okay, back to SoCal. We all know that sooner or later, there'll be another "big one" down that way related to the San Andreas fault system. Many
Americans, especially in that region, call it "
The Big One", probably because they are ignorant of the fact that Cascadia's fault system is
capable of a quake at least a full magnitude bigger. I expect most of us here are well aware of that, but okay, for the Californians, the one they
need to focus on is their own.
I mentioned yesterday that my own feeling is a major event could occur offshore. Or, as I put it, a major event could be
initiated offshore.
That is, while the common feeling or theory is that any big quake has to occur along the one of the land-based faults (or an interconnected section of
them), I suspect that faults off the coast might also play a role. It's just that I'm puzzled by the faults that seem to start off along/near the
SoCal coast and then fizzle out, leading me to think they may extend further Sth and possibly even join up with the "main" offshore fault somewhere
below the Baja Peninsula.
In other words, I have a suspicion (nothing more!) that there could be a mini or micro plate down that way, but one which is not properly charted yet.
If it exists, it would make sense to me that the Baja Peninsula might be part of it, with the majority of the (possible) plate below the sea.
This admittedly fragile hypothesis could help to explain why there was that rather odd mag 6.3 quake that occurred about 175 miles WSW of San Diego in
the sea (ie west of the Nthn Baja Peninsula) on Dec 14 last year. It was the first significant quake in that area in some decades. Then, a couple of
months later, we get that odd event with the dolphins off San Diego, and more recently the mystery with the sea lion pups. And just a little further
north, the subsea methane release.
If not a mini plate, there could still be a fault that runs further S/SE but which has not been charted yet. It's quite possible, especially if it is
generally not very active and sits quietly for long periods. For example, over in Athens (Greece), there was a serious earthquake in 1999, just 17 km
from the city center (a tad over 10 miles). It killed 143 people -- their worst natural disaster in around 50 years -- and it occurred on a fault that
the local scientists didn't even know existed! And that's in a region that has been constantly inhabited for thousands of years, and where quakes are
quite common.
You'd think they'd know every fault in the region, but they didn't "discover" that one until it let go with a mag 6.0.
And that's a lesson for us all. Especially in a region that is known to be seismic we can never assume we know where all the dangerous faults are.
That's why I'm not afraid to say that maybe, just maybe, there is more going on in the offshore SoCal region than we know about. It's also why I feel
that offshore activity there could initiate other activity, meaning that a larger event on land doesn't have to
start on land.
edit on 16/3/13 by JustMike because: (no reason given)