posted on Sep, 28 2003 @ 11:03 PM
Im not a geological expert, just a hobbiest, perhaps someone else, like DR or other resident geo gods can make some perspective on them> Also the
site only shows earthquakes up to the 15th of sep, nothing about more recent activity, which is what Im curious about. The ones on there are tiny and
pretty run of the mill seismic activity for the big monster, so nothing odd there. Wonder if tho it has any bearing on other sesmic activity? Posted
by Skadi
Well, all the quakes resgistering are very low level, which is really not too unusual for a quiet volcano... Also, the maximum depth of 8.7 KM
indicats that it is not associated with mass tectonic shifts... Keep in mind, the tectonic plates extend 20-60 KM in middle of the ocean, and another
60+ KM of continental crust on top of that around where Mt. Rainier is...
I would interpret this data as simply an instance of Mt. Rainier making minor localized adjustments to stress... again, not a major situation, this is
normal in most all fault zones and other seismic areas.
However, in ANY area where deep stress is known to be building, and a noted lack of seismic activity, or other exit for this seismic energy exists,
this is bad news.... It means that the underlying rock units are simply absorbing and storing this slowly buiilding stress, and will conitinue to do
so until the amount of strain exceeds the tensile strength of the rock unit, at which point it will fracture violently, releasing the energy in a
seismic event...
Massive (8.5+) quakes and eruption are often preceded by moderate quakes (around 4.0 mag, such as what we are watching for at Yellowstone) and these
"precursor" quakes should be noted, as it indicates that strain is increasing to the point to break significant rock structures, resulting in larger
and larger quakes...
So, remmeber the 3.0-4.0 quakes at Yellowstone a few weeks ago????