The plume from Tungurahua in Ecuador as seen on August 19, 2012. Webcam capture by Eruptions reader Kirby.
It is that time of year again – the summer is ending and classes begin within a week. Now, I am on leave for the fall, but that doesn’t mean the pace of things isn’t picking up. I spent the end of last week blasting zircons with a laser up at Michigan State in order to get some ages on those crystals and in about 2 weeks from now, I’ll be headed back to California for a week of field excursions across the Sierras. So, busy indeed.
Things have also settled down a smidge volcanically as well. After the New Zealand trifecta, we’ve had some rumblings around the globe … so I thought I’d just use today’s post to catch up with some news I’ve seen (or posted links to on Twitter).
It took a little bit to decipher, but it appears that the Grozny Group in the Kuril Islands may have had its first eruption since 1989. A couple of reports out of Russia suggest that the Ivan Gronzy (Ivan the Terrible; see above) dome in this cluster of lava domes within a caldera may have had a small eruption that spread ash across Iturup Island. One article says that the plume may have only been ~1 km, but it was enough to for people to note ash fall in Goryachiye Klyuchi (9 km) and Kurilsk (25 km).
Beyond this, the news is, well, hard to understand. The article in the Moscow Times claims that the eruption was caused by “increased water flows rushing into the volcano after heavy downpours” and that people noticed “hydrogen peroxide fumes“. Now, I’m hoping a lot of this is merely lost in translation as the ITAS TASS article talks about there no longer being a hydrogen sulfide odor in the area.
In any case, if this eruption is confirmed, it is the first at the Grozny Group since 1989. The complex of volcanoes is a very hydrothermally active area, with strong fumaroles, mostly at Machekh Crater. However, all the historic eruptions from the Grozny Group, including the one in 1989, have come from Ivan Gronzy, as this new eruption seems to be as well.
Aerial view by the New Zealand Navy of a pumice raft spotted near Raoul Island in the Kermadec Islands on August 10, 2012. Image from the New Zealand Herald.
Just think, one week ago I was saying that 2012 was a relatively quiet year for volcanic eruptions. We haven’t made up all the ground of the more active years like 2010-11, however New Zealand had one of its more exciting volcanic weeks in a century – White Island and Tongariro both had eruptions and yesterday a large pumice raft was spotted north of the island nation. This pumice raft (see above) is the product of a submarine volcanic eruption from one of the multiple of seamounts that are part of Kermadec arc north of New Zealand. Exactly which volcano is the source of the pumice is unclear – early on, it was suggested that Monowai was the source, but that seems to be in some question based on the location of the 26,000 square kilometer pumice raft (see below). The raft is located to the northeast of Raoul Island, one of the active volcanoes of the Kermadec Islands that is above the sea surface. The next known active volcano to the northeast of Raoul is Monowai, thus the suspicion that it may be the source. Likely the only way this actual source will be identified is through matching the composition of this pumice with that of known material from Monowai (or another Kermadec volcano). Rafts like this can travel great distances – some of the pumice rafts from the Krakatau eruption in 1886 washed up on African beaches months later – so trying to determine the exact source of the pumice when it is so widespread is challenging. However, this is likely a significant eruption based on the size of the pumice raft across the ocean surface. Monowai does seem reasonable, though, as it has produced significant eruptions in the last few years.
A raw Aqua/MODIS image of the pumice raft off Raoul Island in the Kermadecs, seen on August 10, 2012. Image courtesy of NASA.
Much like I said yesterday, none of these eruptions are directly connected – Tongariro, White Island and this submarine eruption in the Kermadecs are too far apart to be sharing any magmatism. However, the tectonics that control the formation of volcanoes are all the same – the subduction of the Pacific Plate under the Australian Plate.
Steam seen on August 8, 2012 from one of the sources of the August 6 eruption of Tongariro in New Zealand. Image from OneNews.
The hits just keep on coming this week in New Zealand. We’re seen eruptions from both Tongariro and White Island this week – and White Island seems to be picking up the pace. Last night, reports of volcanic lightning from White Island abounded along the Bay of Plenty and a 300 meter eruptive plume was confirmed for the volcano, meaning. Ash fall was also reported at Papamoa, on the coast near Tauranga, the first ash produced from White Island since 2001. To my knowledge, tours of White Island have not been officially banned yet – even the wording of the GNS Science report suggests that tours are still going on: “GNS advises visitors to take a high level of caution.” This is fascinating because as Eruptions reader Claude G. pointed out, the New Zealand government quickly closed access to the Tongariro area after its eruption on Monday, but the same ban has not been produced for the more-vigourously active White Island. My post from Monday that was lost in tall the eruptive excitement gets into some of the issues of these tours to active volcanoes like White Island. The volcano is still at alert level 2 and aviation alert orange according to the latest GNS Science update.
Meanwhile, more of the results (video) of the Tongariro eruption have become apparent. At least three blast craters were formed along with a fissure on the volcano during the eruption and the volcanic tephra produced a small debris flow that travelled a few kilometers from the crater (like caused by a breached lake at the Te Mari crater and/or mixing with snow on the volcano). The GNS Science overflight also captured some cool images of impact craters from the bombs thrown from the vent area. Things have settled down at Tongariro, with only low levels of seismicity under the volcano, but new video footage of the Te Mari crater area shows the vigorous steaming (see above) around the area of the eruption. Be sure to check out the great gallery of images from Tongariro on the GNS Science Flickr stream. Some early analyses of the Tongariro ash show that is was somewhat fluorine rich – an issue especially important for agricultural interests near the volcano. However, this eruption didn’t produce sufficient volume of ash for the fluorine to be problematic, but a larger, sustained eruption might change that. I did find it frustrating how some media made it seem like fluorine in the ash was both surprising and dangerous. This isn’t really the case as almost all volcanic ash as some fluorine. More interestingly, these early ash analyses suggest that little to no juvenile (new magma) material present. Speaking of the ash plume, the NASA Earth Observatory posted a great night image of the plume from the eruption showing it stretching eastward across the North Island. GNS Science has left Tongariro at alert level 2/aviation alert yellow.
Now, one question that I’ve seen asked in a number of places is “are these eruptions related?”. The answer is yes and no. Yes, White Island and Tongariro are both part of the same volcanic arc, where the Pacific Plate is being subducted under the Australian Plate. This means that the processes that generate the primary magmas that feed the volcanoes are the same – as they are for all the volcanoes of New Zealand. However, White Island and Tongariro are geographically separated by over 220 km, so, no, their respective eruption did not cause/prompt the other. Instead, we’re just seeing another example of the random distribution of volcanic activity that produced a beguiling but ultimately false correlation. Now, if Tongariro erupted in quick succession with Ruapehu, only ~17 km away, then there could be more argument for a shared cause (think something like the Katmai eruption in Alaska in 1912). However, White Island and Tongariro are just too far apart to be directly connected in their magmatic systems.
The webicorder trace for Tongariro in New Zealand showing a potential explosion (near bottom) at the volcano. Image courtesy of GNS Science.
I just saw this come across Twitter but there are reports of ash fall near Tongariro in New Zealand (apparently upwards of 5 cm[!] on state highway 46, north of the volcano) along with an unconfirmed report of “red/orange glow” from the Te Mari Crater. The Desert Road near Tongariro has also now been closed, which suggests an eruption (or hydrothermal explosion) has occurred and rescue teams are headed up to hikers’ huts to make sure no one is trapped near the volcano. GNS Science has raised the alert status to Level 2 after these reports. I’m trying to find some more information so we can confirm this, but the webicorders for Tongariro show what could be an explosion signal (see above). Sadly, there isn’t much of a view in the webcam for the volcano.
A brief explosion from Popocatépetl in Mexico on July 21, 2012. Popo has been one of the few volcanic newsmakers of the year. Webcam capture courtesy of CENAPRED.
One topic of discussion that has come up recently on Eruptions is how volcanically quiet 2012 has been so far. Unlike the last few years where there have been multiple significant eruptions that captured people’s attention, there have not been many such events in the past 7 months. Now, this is not to say that there hasn’t been volcanic activity – there has been plenty. However, we have not seen any large eruption that has been splashed across the media since Puyehue-Cordón Caulle last fall … and not to tempt fate, but it was noted on Twitter last night that there hasn’t been a M7 or greater earthquake since April on the planet. We still have 5 months to go, but so far 2012 has been turning out to the the opposite of the Mayan apocalypse that some people are expecting.
However, is 2012 anomalous? Hardly! Just like when there is a strong uptick in volcanic/earthquake activity, this lull is likely mainly due to the random distribution of volcanic events. Sometimes we get clusters of larger eruptions, sometimes we get quiet times. One quick way to look at this is to think about the number of VEI 4 or greater eruptions over the past 10 years (as a small sampling):
* Note: The estimated eruptive volumes for some of the major eruptions of 2011 are not well quantified due to their location (amongst other things). Puyehue-Cordón Caulle was clearly VEI 4+, but Nabro and Grímsvötn are, at the most, VEI 4, likely below that threshhold of 0.1 cubic km of erupted material.
So far in 2012, no eruption reaches anywhere close to the VEI 4 mark, with the most activity centered around the ever-active volcanoes such as those in the Kamchatka Peninsula (especially Karymsky, Kizimen and Shiveluch), Sakurajima, Kilauea and Santa Maria. New arrivals such as Popocatépetl and Nevado del Ruiz, have only produced minor explosions while some rumbling volcanoes such as Iliamna and Rincón de la Vieja have yet to do much of anything at all. This is all normal for the volcanoes of Earth – sometimes they have a busy years with large eruptions like in 2011 or 2008. Sometimes there are none of the larger eruptions that capture everyone’s attention, but volcanism marches on in the form of smaller eruptions that keep that heat circulating from the interior of the Earth to the surface. In the past, this might have been explained by missing data – it was surprisingly easy to “hide” an eruption – but with the increased monitoring, especially through seismic stations worldwide and satellite imagery, it is hard to imagine a large eruption going on unnoticed on Earth**.
Like I said, 2012 still has 5 months to go, so all this talk of a “quiet” volcanic year might be wiped away with a large eruption. However, just as the times of increased activity don’t suggest that the Earth is “out of control” or “heading to heightened eruptions and earthquakes” due to any number of unfounded reasons, this period of relative volcanic and seismic quiescence doesn’t mean that the Earth is doing anything different that business as usual. (And as noted on Twitter, it also doesn’t mean this is the “quiet before the storm”.)
** Note: One might argue that submarine eruptions could go unnoticed. However, a VEI 4+ would leave telltale signs as well, including pumice rafts, strong seismicity and changes in ocean temperature (locally). As an example, the very small eruption from El Hierro in 2011-12, albeit in shallower water, was easily seen from space.
P.S. 2012 has been a very active year for our closest star, the Sun. Now, I won’t go too far, but why has the Earth been so quiet tectonically when the Sun has been so active? I’ll leave that to the folks who think the Sun somehow plays the dominant role in earthquakes and eruptions.
An explosion from Japan’s Sakurajima caught via webcam – you can see blocks from the explosion hitting the slopes of the volcano (small, grey spots). Image from July 24, 2012 courtesy of the Japanese Ministry of Land, Infrastructure, Transport and Tourism.
Very brief post today, but I wanted to share the video of yesterday’s eruption of Sakurajima. Regular readers of this blog will know that Sakurajima is almost always erupting, usually in the form of small explosions from one of the craters (Minami-dake and Showa). However, occasionally things get a little noisier at the restless volcano – and over the last few days, the explosions were especially impressive, sending ash to Kagoshima, located across the aptly-named Kagoshima Bay. Some of the plumes from these explosions reached as high as ~6 km / 20,000 feet.
You can watch the video of some of the explosions here – and it shows some impressive shockwaves caused by the explosions at the vent (however, I am a little frustrated that they decided to speed up the eruptive action). There is also a great compilation of timelapse video from the volcano over the last few days (courtesy of Eruptions reader Sherine). Don’t forget, there are abundant webcams pointed at Sakurajima as well, so you can see some of this action as it happens.
It wasn’t too long ago that Galeras was the only show in town in Colombia. After Nevado del Ruiz settled from its eruptions during the 1980s, there wasn’t much other volcanic activity in the South American nation than the ever-active Galeras near Pasto. However, now it seems that more volcanoes are getting the attention of the INGEOMINAS (the Colombian Geological Survey). With all this news of Colombian volcanoes, I thought I’d offer a brief tour of the action. Remember, Colombia has a few dozen potentially active volcanoes, so this activity shouldn’t be too surprising. You can check out this page to see what each of the INGEOMINAS alert status mean.
A webcam capture of the June 30, 2012 eruption of Nevado del Ruiz in Colombia. Most of the volcano is obscured by clouds, but the grey-brown ash plume spread ash across the countryside. Image courtesy of INGEOMINAS.
Machín, a neighbor of Ruiz, has also seen elevated levels of seismicity over the past few years. Nothing has occurred beyond earthquakes that suggest rock fracturing that could be hydrothermal or magma movement under the volcano. Machín hasn’t erupted in over 1100 years and not much is known about the dome complex that sits within a 3-km caldera. INGEOMINAS currently has the volcano at Yellow Alert III due to the continued seismicity.
Huila
After over 450 years of quiet, Nevado del Huila came back to life in 2008 with a series of small explosions that has produced ash falls, lahars and lava domes at the summit of the volcano (totally a VEI 3 eruption so far). The eruption is considered to be ongoing, although right now the volcano is merely steaming from fumaroles at the summit and experienced tens to hundreds of small earthquakes each week. Huila currently sits at Yellow Alert III.
The steaming summit of Cumbal seen on August 1, 2010. Fumarolic activity such as this is common at Cumbal, but increased seismicity has prompted an increase in the alert level. Image courtesy of INGEOMINAS.
Cumbal
The latest volcano to join the parade of elevated activity is Cumbal (see above), a composite volcano that last erupted in 1926. A report that was issued yesterday (July 11) from INGEOMINAS has raised the alert status to Yellow Alert III after noticing increases in earthquake swarms under the volcano, along with an increase in the temperature of fumaroles at the summit of Cumbal. There has also been reports of noises coming from the volcano in the past few week as well. Much like Machín, not much is known about Cumbal, with only one other known eruption (in 1877). However, Cumbal has rumbled before without producing any eruption.
Sotará
Even less is known about Sotará, a small volcano near Popayán. There have been no known historic eruptions of Sotará, however in late June, seismometers recorded a swarm of over 900 small earthquakes under the volcano. INGEOMINAS did not raise the alert status for Sotará after the swarm, and the swarm seems to be very transitory in nature – not much activity before and after the June 30 swarm.
Galeras
The southernmost volcano in Colombia, Galeras continues to sit at Yellow Alert III. The volcano has not been as eruptively active over the last few months than in recent years, but seismicity continues as does sulfur dioxide emissions. INGEOMINAS describes the current activity as “a reflection of an evolving process that initiated mainly by the intrusion of magmatic material that began to emerge in mid-March 2012″ – that suggests a period of slow dome growth at Galeras right now.
Does all this activity mean that volcanism is on the rise in Colombia? Probably not – in fact, this might be a great case on how increased volcano monitoring helps us become more aware of how restless volcanoes can be when they aren’t erupting or about to erupt. Many of the volcanoes on Yellow Alert III status, like Cumbal and Machin, are only experiencing earthquakes are no one on the surface would even notice. So before many of these volcanoes were wired with seismometers, they could have experienced activity like this and no one would notice. The same can be said for volcanoes worldwide – we can capture so much more subtle information about volcanic activity today than we could even 15 years ago. This can give that false impression that there is more volcanic activity, but rather, we’re just getting more information about what volcanoes do all the time.
Cleveland (background) and Carlisle (foreground) volcanoes in Alaska seen from an Alaska Airlines 737 in May 2012. Image by Cyrus Read, courtesy of AVO/USGS.
This is pretty much all that is going on in the Aleutians right now – Iliamna, another volcano that showed some restlessness earlier this year, has settled in a pattern of low-level (yet above background) seismicity that leaves it at Yellow alert status. However, the Aleutian’s northern Pacific cousins in Kamchatka are definitely keeping busy, especially Shiveluch, where the volcano has been producing frequent ~6-8 km / 20,000- to 26,000-foot plumes.
Update 14/06 – 13:00 UTC – An increasing number of earthquakes, what is called an earthquake swarm, took place in the early hours this morning. Up to 19 earthquakes in less than 3 hours. Magnitudes have been high, with one reaching M 2.8. All depths in between 19 and 26 km. According to IGN this is normal and part of the seismic process and not the eruption. -Map done by AVCAN website with full list of earthquakes here:
Event
Date
Time
Lat
Lon
Depth
(km)
Mag
Location
1148498
14/06/2012
04:00:02
27.7251
-17.9972
20
0.5
NW EL PINAR.IHI
1148500
14/06/2012
04:32:09
27.7622
-18.0380
22
1.5
W FRONTERA.IHI
1148507
14/06/2012
04:40:20
27.7481
-18.0339
20
2.3
W FRONTERA.IHI
1148514
14/06/2012
04:46:49
27.7432
-18.0379
23
1.4
SW FRONTERA.IHI
1148515
14/06/2012
04:52:39
27.7834
-18.0411
24
1.9
NW FRONTERA.IHI
1148530
14/06/2012
04:59:27
27.7873
-18.0422
21
1.3
NW FRONTERA.IHI
1148531
14/06/2012
05:00:00
27.7596
-18.0381
26
1.4
W FRONTERA.IHI
1148542
14/06/2012
05:14:10
27.7519
-18.0415
22
1.6
W FRONTERA.IHI
1148536
14/06/2012
05:15:10
27.7306
-18.0264
22
1.9
SW FRONTERA.IHI
1148544
14/06/2012
05:22:16
27.7896
-18.0447
20
1.7
NW FRONTERA.IHI
1148546
14/06/2012
05:27:00
27.7569
-18.0432
23
1.3
W FRONTERA.IHI
1148547
14/06/2012
05:34:31
27.8004
-18.0500
19
1.3
NW FRONTERA.IHI
1148549
14/06/2012
05:34:56
27.7735
-18.0356
21
1.5
NW FRONTERA.IHI
1148559
14/06/2012
05:41:04
27.7853
-18.0509
21
1.8
NW FRONTERA.IHI
1148561
14/06/2012
05:54:22
27.8062
-18.0488
20
1.8
NW FRONTERA.IHI
1148562
14/06/2012
06:01:52
27.7644
-18.0395
22
2.3
W FRONTERA.IHI
1148563
14/06/2012
06:05:07
27.7794
-18.0525
22
2.8
NW FRONTERA.IHI
1148565
14/06/2012
06:06:20
27.7726
-18.0591
23
2.7
NW FRONTERA.IHI
1148568
14/06/2012
07:48:40
27.8015
-18.0680
21
2.1
NW FRONTERA.IHI
Update 13/06 – 13:00 UTC – 2 Earthquakes today after 5 days without any, making a total of 36 earthquakes registered by IGN since 1st June 2012.
– The strongest at 04:57 UTC with a Magnitude 1.8 and depth 25km. At 08:10 UTC a soft movement of Magnitude 0.3 and depth unknown. Both similar location, N Frontera.
Update 10/06 – 15:00 UTC – Following the update containing the document from ULPGC, here is the video, showing the volcano at different depth, bubbles and fish swimming along. Recorded by the Qstar Crew of the Atlantic Explorer.
for more information and updates, go to: http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/
