Ok, finally have a day off here, and can answer some questions.
Currently, YS is still in a normal state of seismicity, even with multiple swarms occurring simultaneously in different parts of the caldera-
according to the YVO. I will pass on this link, and I suggest you guys bookmark it for future reference. Because at the end of the day, the YVO are
the people responsible.
If there is any activity worthy of note, it will be summarized in those activity reports.
Basically, seismic activity at Yellowstone is so high over the course of a year, that it would take some pretty serious events for the YVO to raise
the alert level from normal:
1) The discovery of volcanic tremor and/or long period events- which as far as I know have never ever been detected at Yellowstone. And let's hope we
never do detect them. But as with all active volcanoes, one must remain vigilant to insure that if and when tremor/LP does occur, we catch it as soon
as possible. This can potentially be a daunting task for some areas of the park where seismometers are sparse- particularly in the southwestern area.
MCID remains an isolated station, and those that follow my posts may know of the previous battles I've had with scientists over certain signatures I
keep detecting there- but that don't confirm on other stations.
2) A dramatic change in the rate of caldera uplift- or even subsidence.
3) A change in chemical composition and/or quantity of gasses coming from it- that would trend towards increased presence of magmatic melting, as
opposed to increasing crystallization.
4) A sudden increase in thermal signatures, indicating that more heat is present than before.
5) A marked increase in the magnitudes and frequency of swarming earthquakes. As others here have pointed out- when top magnitudes start reaching into
3's and 4's, that is not good. But even then scientists might not raise the alert level- unless along with them tremor/LP's were detected. If swarming
quakes starting reaching peak magnitudes into the 5's however, that would be a game changer.
Monitoring YS is a careful balancing act, between all the factors that would point to an imminent eruption. The normal activity baseline has been
established over a lot years of watching it. My scientific contacts have expressed an interest in reporting swarms to them though, and so when one
starts and I detect it, I fire off an email note immediately after I see more than 15 events.
My primary interest is being watchful for tremor/LP's, during overnight hours when, as you can see from what happened here, the USGS and UU are not
reporting right away what is going on.
Yellowstone is not something we can ever take lightly. We must never become complacent with it, and allow the high seismic baseline to ever beat us
with a surprise BOOM out of nowhere. It is so huge that I take every single swarm very seriously, because you never know if that might be the one that
is the signal. No one can say if the current high seismic baseline might actually be part of the long ramp up to eruption- because no one was around
40,000 years ago to report what may have been near dead quiet. Because previous eruption cycles suggest that we may actually be in the eruption
timeline window for it NOW, we cannot afford to get complacent, even for a minute. Or EVER. And so I watch. And so I report.
ETA: The activity of this recent multiple swarm episode appears to be over for the moment- or we could be in a lull. Dunno. Gotta keep
edit on Sat Sep 14th 2013 by TrueAmerican because: (no reason given)