Tuesday Tidbits: Mayon and Redoubt Updates

Not much new to report today, so I'll just add some notes to the two volcanoes in the news right now: Mayon and Redoubt.


Mt. Redoubt in Alaska, taken on September 23, 2009. Image courtesy of AVO/USGS, taken by Game McGimsey.

Mayon:
The volcano continues to show signs that a major eruption is in the works, but nothing new occurred over the last 24 hours. 2 km / ~5,000 foot ash plumes were produced from the new dome/flow complex, causing a potential aviation hazard, and the lava flows continued to be erupted. In evacuation news, animals are now being evacuated from the hazard zone around the volcano as well. However, life in the evacuation camps for people is leading to some deaths from illness. However, for now, there is still little idea exactly when (and if) Mayon will have the "big one".

Redoubt:
The other news yesterday was the potential return of activity at Redoubt in Alaska. The alert status was raised to Yellow by AVO after a series of small earthquakes at the new summit dome. It is unclear what exactly the earthquakes mean, but AVO scientists say that they look similar to earthquake patterns observed during the spring 2009 eruptions - which is sign enough to raise the alert level. However, the seismicity appears to be decreasing through time, so it is unclear whether any eruption will occur - but AVO isn't overly concerned that something big might happen soon.

More like this

Seache's list has two winners:

(1) Sodd's Second Law: Sooner or later , the worst possible set of circumstances is bound to occur.

Notice that have quite a few volcano's 'loaded for bear' as it were, at Level Orange. We also have an pronounced activity up-tick in other naturally cyclic behaviors.

Their physical connection is not coincidental. Their timing in returning to activity could not be at a worse moment. (eg., Zumurgy's seventh exception to Murphy's Law:
When it rains, it pours.)

(2) Clarke's Second Law: The only way to discover the limits of the possible is to go beyond them into the impossible.

Churchill's Corollary to Clarke's Second Law: What you once assumed to be impossible will be found to be merely improbable for want of imagination and creative problem-solving.

Ash eruption at Mayon to 9,000 feet asl. This is the first VAA for Mayon since the 19th of December.

Received FVFE01 at 00:37 UTC, 30/12/09 from RJTD
VA ADVISORY

DTG: 20091230/0037Z
VAAC: TOKYO
VOLCANO: MAYON 0703-03
PSN: N1315E12341
AREA: PHILIPPINES
SUMMIT ELEV: 2462M
ADVISORY NR: 2009/10
INFO SOURCE: MTSAT-1R RPLL
AVIATION COLOUR CODE: NIL
ERUPTION DETAILS: ERUPTION FL090 EXTD NW WAS REPORTED AT 20091230/001

7Z.
OBS VA DTG: 29/2332Z
OBS VA CLD: VA NOT IDENTIFIABLE FROM SATELLITE DATA. WINDS ABV THE
VO
LCANO AT 30/0020Z FL090 050/12KT FROM JMA NWP MODEL.
FCST VA CLD +6HR: NIL
FCST VA CLD +12HR: NIL
FCST VA CLD +18HR: NIL
RMK: NIL
NXT ADVISORY: NO FURTHER ADVISORIES=

By Chance Metz (not verified) on 29 Dec 2009 #permalink

I wish PHIVOLCS would produce a little more detail than this:

"the volcano edifice remains inflated as indicated by the electronic tilt meter installed at the northeast sector of the volcano."

Inflated by how much? Is the inflation increasing or decreasing? Is there evidence of a cryptodome?

Is there a better Mayon site someplace?

It would be interesting to know what sort of earthquake shocks are happening at Redoubt. "Blue blurbs on the screen" isn't too informative. Long-period quakes beneath an apparently quiet dome presaged a previous Redoubt explosion in 1989

To me they appear(ed) to be small, shallow rock-breaking type earthquakes. I tried to analyze them in detail and I didn't find long period signals due to magma movement. They might have been caused by a sudden/fast change in dome stresses, but the cause might be as well something else.

I think it's probable anyway, after the AVO team will conduct fieldwork today (including seismic station/cameras maintenance and probably gps data gathering from non-realtime stations), that the volcano alert codes will be lowered back to green/normal, as the number of earthquakes has reduced greatly, now close to normal.

Of course, if it turns out that volcano gas output has increased since last time and/or that gps stations report ground inflation, the situation could be different.

By SHIRAKAWA Akira (not verified) on 31 Dec 2009 #permalink