[Sca-cooks] small earthquakes

[Sharron Albert]

>Urtatim commented:
>
><<< (boom, rattle, rattle, rattle)
>Sh*t, that's the third earthquake in the past 3 or 4 days, all the
>same magnitude and with the epicenter just a couple miles from my
>house.
>
>Stefan replied:
>
>I'm sorry to hear of your discomfort. But I suspect that these small 
>earthquakes are actually good, since they let off some of the 
>building pressure. These small quakes do minimal damage, even if they 
>are disconcerting. However, if the pressure between the sliding 
>tectonic plates is not occasionally relieved, it continues to build 
>until it overcomes the friction holding the plates back and that is 
>when you get the much bigger 6, 7 and 8 magnitude (on the Richter(?) 
>scale) quakes. Those are the ones that do major damage and in which
>people get hurt and killed.
>

On the other hand, small quakes can be harbingers. We had a bunch of 
smaller quakes in the 3-4 point range in the Talkeetna area strong 
enough to be felt in Fairbanks (about 150 miles away iirc) before the 
big 7.9 one that rattled the state a couple years ago. I kept feeling 
them (after the Good Friday Earthquake so many years ago I'm 
relatively sensitive to earth movements), and looking them up on the 
Alaska Earthquake page, and noticed the clustering. I actually said 
to myself "hum, it looks like something's going on down there." Then 
we had one around 5.9 followed by the big one and all the aftershocks 
as the major fault line shifted sideways across the state to 
compensate over the ensuing months.

So, yeah, mostly small ones are good. But specific clustering should 
be watched carefully...

Morgana, in snowing Fairbanks (which will make the skiers happy)
-- 
Tactics is knowing what to do when there is something to do. Strategy 
is knowing what to do when there is nothing to do. --Savielly 
Tartakover, GM, quoted in "The Eight" by Katherine Neville