Friday Flotsam: Undersea volcanism revisited and a Mayon update

It is interesting that West Mata is more vigorous than NW Rota 1 in the Marianas, even though that vent is only ~ 5oo meters down. Of course we've only seen each volcano for brief periods, so the full range of their activities has not been observed.
We should give an internet round of applause to the NOAA crew for finding both volcanoes. I know a few of them and they have logged many a nautical mile and spent many days underway to finally provide us with views of the hidden volcanoes of the world.

Absolutely amazing footage and I was also in awe of how explosive this eruption is given the ambient pressure... I wonder what something like that looks like at the surface? The intensity of sulfur in the eruption cloud also intrigues me... Is it simply more visible because of the aquatic setting or is this eruption particularly sulfur-rich?

bruce,
S contents have been the subject of considerable interest at NW-Rota 1 in the Marianas as well, where the vigorous activity has been attributed to sulfur degassing and blebs of sulfur were deposited on the first ROV to invetgate. However, according to Alison and others, melt inclusions have S contents typical of the Mariana Arc, and they suggest that the observed SO2 degassing is due to efficient exsolution at the eruption depth.
Shaw et al., 2006, Volatile Contents of NW Rota Melt Inclusions: Insight to Explosive Submarine Arc Volcanism, Eos Trans. AGU, 87(52), Fall Meet. Suppl. Abstract V52B-05

Here's nice video of some recent activity at Mayon - including a seemingly unconcerned farmer and his cow in the foreground: http://www.youtube.com/watch?v=1X8xl6qhXTI

Is there a Mayon Web cam ?

Also on a totaly different item. Does anyone know the VEI for Redoubt this past March, April.

How come the press are saying that West Mata is the first explosive submarine eruption to have been observed? Am I missing something, or didn't the Rota eruption take place earlier? The photos from that one were pretty spectacular, too.

Zwirko:
I got the impression that cow was GENUINELY unconcerned.

mike don,
I think the press is misreading or confusing something. NW-Rota was first seen erupting in 2004, West Mata this year. In fact, NW-Rota first attracted interest due to a low-pH plume detected in 2003 and the activity has been visually observed in every subsequent visit since '04.

Ekoh; thanks for that, I wasn't dreaming. The Press (not for the first time) has got its volcanic story tangled. The large quantity of elemental sulphur in the plumes (at both Mata and Rota) compared with land-based eruptions is interesting. Could it be that in an environment without free oxygen less of the sulphur is oxidised to SO2 at the vent?

dasnowskier: I don't have a definitive answer on Redoubt, I'd guess similar to the last eruption, which was VEI 3, but I'm open to correction

Just another 6,000 foot ash explosion.

Received FVFE01 at 03:02 UTC, 19/12/09 from RJTD
VA ADVISORY

DTG: 20091219/0301Z
VAAC: TOKYO
VOLCANO: MAYON 0703-03
PSN: N1315E12341
AREA: PHILIPPINES
SUMMIT ELEV: 2462M
ADVISORY NR: 2009/7
INFO SOURCE: MTSAT-1R
AVIATION COLOUR CODE: NIL
ERUPTION DETAILS: POSSIBLE ERUPTION OBS AT 20091219/2332Z FL060 EXTD

SW ON SATELLITE IMAGERY.
OBS VA DTG: 19/0159Z
OBS VA CLD: UNKNOWN/FL060 N1252E12321-N1236E12307-N1231E12314-N1248E1

2326 MOV SW 20KT
FCST VA CLD +6HR: 19/0759Z SFC/FL200 N1100E12130-N1100E12200-N1200E12

200-N1200E12130 FL200/550 NO VA EXP
FCST VA CLD +12HR: 19/1359Z SFC/FL200 N1000E11900-N1000E12000-N1100E1

2000-N1100E11930-N1030E11900 FL200/550 NO VA EXP
FCST VA CLD +18HR: 19/1959Z SFC/FL200 N0830E11730-N0830E11830-N0930E1

1830-N0930E11730 FL200/550 NO VA EXP
RMK: NIL
NXT ADVISORY: 20091219/0600Z=

I sailed over West Mata Volcano in the night of 24-25 October 1975 with the 63-foot motor-ketch Kawamee encountering a minimum depth of 1400 meters. There was no road sign to tell me its name but the appearance of it shape on the echogram was remarkable. I wrote,"... the track during the search was well determined. As the sky was clear and the horizon well illuminated by a bright moon, a round of star sights was taken at two-hours intervals through the night. The shallowest spot found was at the northern limit of the search pattern where a peak reached sharply to 1400-meters depth. The general depth is about double this."

The search mentioned was for Curacoa Volcano which I explored on 30 October 1975. Six days before encountering West Mata, I had discovered the active submarine volcano to the southeast of the Samoa chain and given it the name of Rockne Volcano. This name was deemed "culturally insensitive" by some who renamed it Vailulu'u.

My chart of the encounter with West Mata has Kawamee's track displaced about 1 nautical mile to the southwest. That is not bad for celestial navigation at night.

So we all know Mayon may erupt soon... I read many articles about volcanoes so i kinda know the basics... Mayon is a Stratovolcano and it is a big volcano about 2450 m high.. It erupted almost 48 times in since 1616. Some where weak other were stronger.. I keep reading to some articles that a major eruption may be imminent.. or a hazardous eruption... or a full-blown eruption... but how much hazardous?? Do they know? Or can they know? Erik said it sounds like a true Plinian. Is it not that VEI 5 or more? Can it be one serious one like Pinatubo's maybe? I know that this volcano's eruptions (at least these recorded) were at least Vezuvian but -though unrecorded- i heard that, theoritically, it has what it needs for an eruption that it may have climate effects. (though its not something so rare for stratovolcanoes) So do they actually know what COULD happen? I am very curious to know but i am also very skeptical to these matters.. especially when i can not find an article which states that it may NOT erupt violently enough to affect climate...

I am awaiting for an answer if possible i see that there are many experienced people here that can answer.. By the way i am not a seeking-for-danger person but real truth needs further searching in order to gain it. Thank you for reading this.

To Alex: theoretically, nearly all volcanoes are capable of producing very large eruptions. That is, all volcanoes capable of erupting anyway. Even the Hawaiian volcanoes, like Kilauea, are now known to have produced quite powerful explosive eruptions in the recent past (a few centuries ago) and will do so again within the next few centuries. Yet, each time a volcano acts up, the probability that this new eruption will be a cataclysmic one is relatively small, at some volcanoes a bit more, at others a bit less. Mayon seems to be pretty content with the way it's been erupting over the past few hundred years, most eruptions being somewhere in size between the rather effusive 2006 (or the similar 1978) eruption, and the quite powerfully explosive 2000 (or 1984) eruption. There are two much larger eruptions known in the past 200 years, a Plinian one in 1814 and a (probably sub-Plinian) powerful, destructive and deadly one in 1897. I think that is basically the palette of possible scenarios, and given that about 90 per cent of Mayon's historic eruptions fall into the lower range of the spectrum, that's where probabilities lie for the current eruption. And, after all, let's wish those people living around Mayon anything else than a cataclysmic eruption at Christmas.

By the way, we're having a quite remarkable seismic swarm at Etna, with dozens of events having magnitudes between 2.5 and 3, and two main events with magnitudes of 4.2 at 05.36 GMT and 4.6 at 09.01 GMT. The earthquake hypocenters lie at depths between 15 and 20 km, which is quite deep for Etna, and are centered below the northwestern flank of the volcano, which commonly is one of its less seismically active sectors. So far there's no indicator that these earthquakes are related to magma movement.
Seismic signals of two of the seismic stations on Etna can be looked up here:
http://www.ct.ingv.it/Etna2007/SegSismici.asp?Staz=ESVO_HHZ_IT&Pos=6
http://www.ct.ingv.it/Etna2007/SegSismici.asp?Staz=ESPC_HHZ_IT&Pos=6

To Boris > Thank you for your reply though i am still a bit confused. Excuse me but what do you actually mean when you say:"I think that is basically the palette of possible scenarios, and given that about 90 per cent of Mayon's historic eruptions fall into the lower range of the spectrum, that's where probabilities lie for the current eruption" Can you express that with more simple words please, i have got some difficulties in translating such english! Thank you

To Alex: let's try to be clear. What I wanted to say is that most eruptions of Mayon are not particularly big (on a global scale), and it is probable that the current eruption will be similar to most of the past - not particularly big - eruptions. But then, you never know. Fifteen years ago, nobody would have expected that Soufrière Hills on Montserrat (West Indies) would make an eruption that would last so long (since July 1995) and become one of the largest dome-building eruptions on Earth during history.

And here we go for an update about Mount Etna, the volcano in my backyard. Since shortly after 05 h (GMT) this morning, there has been a swarm of earthquakes, all centered at some 15-20 km depth below the northwestern flank of the volcano. There have been a few dozen events with magnitudes between 2.5 and 3, and two major shocks (at 05.36 GMT, magnitude 4.2, and 09.01 GMT, magnitude 4.6; I felt these two quite strongly in my home on Etna's southeast flank). The area of this seismic activity is quite unusual for Etna, where shallow (mostly less than 5 km below sea-level) seismic activity is concentrated in the northeastern, eastern, and southeastern sectors, whereas somewhat deeper seismicity is typical below the southern and western flanks. There seems to be currently no evident relationship with magma movement, although often seismic activity at Etna is an expression of magma accumulation and uprise. We'll see ...

So what i understand is that it is all about matter of chances.. Eruptions with global effects are more rare but rare also happens sometimes. So as you say, well umm lets see!

To predict the future, look to the past. You can reduce, but not eliminate 'chance' by looking at the record.

I think it's safe to say that no magma chamber of any size is beneath Mayon, and there isn't much variability on the chemistry of the erupted magma supplied.

So the only wild cards that I can see which would cause Mayon's eruptive style to change from the recent Strombolian-to-Vulcanian to something approaching Plinian would be: 1. Gas content, 2. Speed of magma ascent, 3. Temperature of the ascending magma, and 4. How plugged the conduit was from the last eruption.

Now obviously one can't rule out a Plinian eruption, but a lot of variables would have to be pegged to their extremes in order for it to happen. For a lot of volcanoes, these extremes are the norm, but not in Mayon's case.

According to Yahoo, Mayon is of increasing concern.

http://news.yahoo.com/s/ap/20091220/ap_on_re_as/as_philippines_volcano

The latest I am reading in the Philippine press is that they are expecting this eruption to be much stronger than eruptions in the recent past due to the strong unrest currently being experienced there. There were over 450 earthquakes in a 6 hour period yesterday, SO2 production at over 7,000 tons/day and continuous harmonic tremor.

Of course it could all simply stop tomorrow, one never knows, but activity of this sort is the type that often precedes strong eruptions, according to my reading. Yesterday Phivolcs was expecting an eruption after the New Year, today they are saying that one before Christmas is now likely.

Lets just hope it is able to vent gas at a rate fast enough to prevent a catastrophic eruption for the locals.

The alert level has been raised to 4. Seems that big blast is almost here.

Any bets on whether it does a Redoubt and keep us waiting for 2 months?

Mayon's going to blow! almost 2,000 earthquakes in one day and lava shooting high in the air. When the volcano starts to rumble it it time to duck for cover! It sounds like it is literally rumbling.

Mayon Volcano Bulletin 8
21 December 2009

7:00 AM

Mayon Volcanoâs (13.2576 N, 123.6856 E) activity escalated during the past 24-hour observation period. Seismic activity dramatically increased in number and size. A total of 1,942 volcanic earthquakes was detected by the seismic network. Many of these volcanic earthquakes were recorded at maximum deflection and continually occurred beginning at 1221H yesterday. Harmonic tremors were also continuously recorded.

Sulfur Dioxide (SO2) emission rate remained very high at 6,089 tonnes per day (t/d). Audible booming and rumbling sounds were first reported in the eastern flank of the volcano at about 1455H then occasionally occurred beginning 2200H last night. Intensified crater glow and rolling down of incandescent lava fragments from the crater was also persistent. Red hot lava also continuously flowed down along the Bonga-Buyuan, Miisi and Lidong gullies. Lava fountains rising approximately 200 meters above the crater were observed at 2007H, 2008H and 2018H. The lava front has now reached about 5 kilometers downslope from the summit along the Bonga-Buyuan gullies.

Alert Level 4 is hoisted over Mayon Volcano, meaning a hazardous eruption is possible within days. Thus, PHIVOLCS-DOST reiterates that the Extended Danger Zone (EDZ) from the summit of 8 km on the southern sector of the volcano and 7 km on the northern sector be strictly observed. Areas just outside of this EDZ should prepare for evacuation in the event hazardous explosive eruptions intensify. Active river channels and those perennially identified as lahar prone in the southern sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall. PHIVOLCSâDOST is closely monitoring Mayon Volcanoâs activity and any new significant development will be immediately posted to all concerned.

With the latest news, if someone search on google will realise that there are not any possibilities (or at least thats what they say so , or what they CAN say so with the most recent date) for it to be compared to a Pinatubo eruption. Though they say it will be stronger than 2001 and 2006 but not as strong as Pinatubo. Pinatubo ejected billions of debris. Mayon will only eject millions... Still many but not a colossal number.

This is what has caught my eye. "Lava fountains rising approximately 200 meters above the crater were observed at 2007H, 2008H and 2018H."
A 650 foot lava fountain = 65 story high Lava fountain. How hi can these things get?

Dasnowskier--it's probably not a Hawai`ian-style lava fountain. More likely a Strombolian burst. Remember the km-high 'lava fountains' at Etna? Impressive as heck, but it appeared to be paroxymal Strombolian. As far as I know, the record for a Hawai'ian lava fountain is aroung 600m.

All depends on the gas content and how quickly the gas can exsolve from the magma.

Damon,
Thank you for the information. A Strombolian burst sounds more likely especially when I see the images of the glowing boulders rolling down the volcano's slopes.

600 meters for a true fountain...WOW

I just wish it would erupt now and get it over with. After waiting moths for Redoubt to erupt I was begining to think nothing would happen.

Dasnowskier and Damon, the lava fountains at Etna are true lava fountains (not Strombolian activity which, per definition, consists of single, separate, discrete explosive bursts), and they are the highest ever recorded on this planet: more than 2000 m on 4 September 1999 ... and we who live and work here on Etna would love to see some lava fountains soon again, it's been nearly two years since the last one.

While hunting for some footage of Mauna Loa eruptions I found this little historical gem in youtube from 1935:

http://www.youtube.com/watch?v=fu5soxn5ydM

and here are some larger fountains from Kilauea 1969:

http://www.youtube.com/watch?v=9mOTTBZoezU&feature=related

and here is some awesome footage from Etna 2000. Boris probably has better links but this gives you a pretty good idea. The good stuff kicks in at about 6 minutes.

Boris, I have a question. This is a pretty big eruption cloud but made up mostly of scoria and gas.. is it possible to get pyroclastic density currents from this kind of eruption column?

Another bulletin and another day waiting for the big blast to happen. Nothing really new here to talk about.

Mayon Volcano Bulletin 10
23 December 2009

7:00 AM

Mayon Volcano (13.2576 N, 123.6856 E) continued to show an intense level of activity during the past 24-hour observation period. Seismic activity remained elevated in number and size as the seismic network detected 1,051 volcanic earthquakes and continuously recorded harmonic tremors. Many of these volcanic earthquakes were recorded at maximum deflection. Sixty six (66) ash explosions were observed during times of good visibility. These explosions produced grayish to light brown ash columns that reached height from 100 to 1000 meters above the summit before drifting towards southwest.

Sulfur Dioxide (SO2) emission rate remained very high and was measured at an average of 6,737 tons per day (t/d) yesterday. Two hundred eighty (280) audible booming and rumbling sounds were intermittently heard for the past 24 hours. Red hot lava also continuously flowed down along the Bonga-Buyuan, Miisi and Lidong gullies.

Alert Level 4 remains hoisted over Mayon Volcano, meaning a hazardous eruption is possible within days. Thus, PHIVOLCS-DOST reiterates that the Extended Danger Zone (EDZ) from the summit of 8-km on the southern sector of the volcano and 7-km on the northern sector should be free from human activity. Areas just outside of this EDZ should prepare for evacuation in the event hazardous explosive eruptions intensify. Active river channels and those perennially identified as lahar prone in the southern sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall. PHIVOLCSâDOST is closely monitoring Mayon Volcanoâs activity and any new significant development will be immediately posted to all concerned.

Bruce, you forgot to stick in the link for the Etna eruption - post #30

Great footage. To quote Monty Python "run away run away"
What would the temperature range be of such liquid lava ?

Another ash plume from Mayon,this time only to 4,000 feet asl.

Received FVFE01 at 01:56 UTC, 23/12/09 from RJTD
VA ADVISORY

DTG: 20091223/0156Z
VAAC: TOKYO
VOLCANO: MAYON 0703-03
PSN: N1315E12341
AREA: PHILIPPINES
SUMMIT ELEV: 2462M
ADVISORY NR: 2009/9
INFO SOURCE: MTSAT-1R RPLL
AVIATION COLOUR CODE: NIL
ERUPTION DETAILS: VA OBS FL040 EXTD SW WAS REPORTED AT 20091223/0137Z

OBS VA DTG: 23/0059Z
OBS VA CLD: VA NOT IDENTIFIABLE FROM SATELLITE DATA. WINDS ABV THE
VO
LCANO AT 22/0050Z FL040 070/28KT 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=

sorry Thomas.. here you go. As I said the good stuff starts at around 6 mins.

http://www.youtube.com/watch?v=HRjLw1x8Q3o

Hi, Boris: Thanks for slapping me on the back of the head to remind me about one distinction between Hawai`ian v. Strombolian--the discreteness of the bursts. One can lose some perspective just by looking at still photos, so I looked at the Youtube video mentioned in post #35. One thing I take away from that video is that one can't make generalizations--some of Kilauea's 1959 and 1983-84 high fountains look remarkably like Etna in 2001-2002.

So I just won't make generalizations anymore (!)

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