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| Science Forum Index » Geology - Earthquakes Forum » 666 and all that.... |
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| Weatherlawyer... |
 Posted: Mon Oct 12, 2009 5:18 am |
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Guest
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Hebron-ish, Newfoundland is 60 degrees north and 60 degrees west. Not
many places up there but the peninsula is in the region of... so to
speak.
Savannah is on an arc something like 30 degrees from Hebron. It’s on
the south west coast of the North Atlantic.
On the north east coast of the same ocean lies Britain. Thank you
Columbus! And on the North West extreme of the arc centred Hebron,
lies the source of the Pacific borne, Alaskan bay lows that cross the
Rockies and...
The perimeter of the disc (radius 30 degrees) follows the eastern edge
of the Rockies, going through Yellowstone from the Mackenzie river in
Alaska. Then it hits the Platte; then on through Kansas between Topeka
and Wichita through Arkansas, Alabama (near Columbus) and out on the
border of Georgia and South Carolina between Savannah and Charleston.
And north of Britain it skirts Norway, hits Spitsbergen (just) and
passes pretty close to the North Pole.
All interesting places. (Lucky old us.)
When the Low comes ashore at (for example) Alaska from the North
Pacific, it splits up as the constituents fall apart. Then as the
various acoustic waves go their own ways (http://www.youtube.com/watch?
v=yqiBT-YXAh0) they tend to drop the overall pressure of the now
attenuated and extensive Low in the Midwest to not much less than 1016
millibars -the sort of stuff that is associated with tornadoes
(funnily enough.)
And then from all directions they (said diffused waves) gather towards
the coast just off the place where the Gulf Stream’s current is at its
most powerful.
OK?
Now let’s widen it out.
As a Low -or for that matter an High, leaves the continent at Georgia
or the Carolinas, there is a dramatic increase in the magnitude of the
earthquakes that occur near the Rat Islands on the Aleutian
Archipelago. The number of quakes usually drops and the somewhat
frequent incidence of magnitude 1 and 2 tremors become two or three
2.5 to (occasionally) 4 to 5 Mag quakes.
And these of course are 80 degrees from Savannah and Charleston. And
60 degrees from Hebron, Newfoundland. Giving Hebron the "man’s number"
so revered by idiots who aught to check their facts carefully.
And what does this all mean? Blowed if I know.
I don’t know what it all means but I am glad I am able to dispense
with the 80 degree ratio between that part of the North American coast
of the south-eastern USA. Interesting though it is. (Always felt
stymied by that one!)
A 60 degree radial arc gives us that shadow zone beloved of
seismologists.
Apparently because of the Mohorivicic discontinuity and its ilk, sound
waves are supposed to disappear in the region 105 to 135 degrees-ish
from what most think is the epicentre of the (for want of a better
word) “Earthquake”.
(I’m quite happy with the term “earthquake” really. I just wanted to
make the point that several other terms need rethinking.)
Well. That’s another anomaly.
Let’s see what not thinking about it for a few years will supply us
with.
(Anyone here interested in Milankovitch cycles or whatever?) |
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