Unrest Continues at Ubinas 16.355°S, 70.903°W

Current Status

After a three year quiet period, in July 2013 a pilot-reported ash plume rising to an altitude of 18,000 ft a.s.l. signalled the start of a three month eruptive phase at Ubinas. GVP reported that this eruptive activity was VEI 2 [1]. Ubinas has been restless again since January 2014, following resumption of seismic activity, with frequent plumes of gas and usually light ash. By 14 April 2014 she was producing explosive eruptions with ash plumes up to 37,000 ft a.s.l. [1,2].

The current alert level was raised to orange on 16 April 2014, following a significant increase in the exhalation energy values / explosions, suggesting a possible breaking of the dome. SO2 levels indicate that magma is continuing to rise. The eruption of pyroclastic fragments of 20 cm to 30 cm to a distance of 1.5km to the west of the crater was reported on 15 April 2014. [8]

Evacuations of people and livestock from Moquegua and Arequipa to temporary shelters have commenced as a precautionary measure. An eruption on 2006 released toxic gasses and ash which killed livestock [3]. Jose Machare from the Peruvian Institute of Geophysics is quoted as saying that there was a “low possibility” that that latest activity could develop into an “unusual eruption that could be very big”. [3]

Fig 1:  Ash cloud observed on satellite imagery at 12:45 GMT on August 14, 2006. Source: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=16615

Fig 1: Ash cloud observed on satellite imagery at 12:45 GMT on August 14, 2006. Source: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=16615 Toxic gasses from the eruption killed livestock and forced an evacuation.

 

Fig 3:    Seismogram showing activity at 19/04/2014 22:22 UTC.  Source: http://vulcanologia.igp.gob.pe/ub1.php

Fig 3: Seismogram showing activity at 19/04/2014 22:22 UTC. Source: http://vulcanologia.igp.gob.pe/ub1.php

Fig 4:  Heat sources shown for the last seven days as at 19/04/2014.  Source: http://modis.higp.hawaii.edu/cgi-bin/modis/modisnew.cgi

Fig 4: Heat sources shown for the last seven days as at 19/04/2014. Source: http://modis.higp.hawaii.edu/cgi-bin/modis/modisnew.cgi

Geology of Ubinas

Ubinas is one of Peru’s most active volcanoes, comprised of layers of silica-rich lava flows. At the summit there is a 1.4 km wide and 150 m deep caldera which contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. [1,11]

Fig 5:  Image by: Norm Banks (U.S. Geological Survey), published under Wiki Commons Licence, Source:  http://www.volcano.si.edu/volcano.cfm?vn=354020

Fig 5: Image by: Norm Banks (U.S. Geological Survey), published under Wiki Commons Licence, Source: http://www.volcano.si.edu/volcano.cfm?vn=354020

She is situated about 50 km behind the main volcanic front of Peru, 230 km east of the Peru-Chile trench in the Central Volcanic Zone on a plateau formed from Oligocene-Miocene (Neogene) ignimbrites and intrusive rocks. Here, the Nasca plate subducts beneath the South American plate at a dip of 20° -30°. Ubinas, herself, is about 150km above the Benioff-Wadati plane. [5,6]

Fig 6:  Tectonic setting showing the plates and approximate locations of the South American Volcanic Zones.  Source:  Google Earth with text added by the author.

Fig 6: Tectonic setting showing the plates and approximate locations of the South American Volcanic Zones. Source: Google Earth with text added by the author.

Fig 7:  Location of Ubinas in the Central Volcanic Zone.  Source: Google Maps.  You can also see a section of the Peru-Chile trench in the lower left hand part of the image.

Fig 7: Location of Ubinas in the Central Volcanic Zone. Source: Google Maps. You can also see a section of the Peru-Chile trench in the lower left hand part of the image.

Plotting the latest 3,000 earthquakes reported by IRIS for the area shown below, we can see the subduction zone:

Latitude v Longitude as shown by IRIS:

Fig 8:  Location of the most recent 3,000 earthquakes from IRIS as at 20 April 2014.  Source: http://www.iris.edu/hq/

Fig 8: Location of the most recent 3,000 earthquakes from IRIS as at 20 April 2014. Source: http://www.iris.edu/hq/

Fig 9:  Plot by the author of Longitude v Depth rotated slightly for the above earthquakes to show the subduction of the Nazca plate under Peru. Colours indicate depth in km. Plot reproduced with her permission here; copyright rests with the author.

Fig 9: Plot by the author of Longitude v Depth rotated slightly for the above earthquakes to show the subduction of the Nazca plate under Peru. Colours indicate depth in km. Plot reproduced with her permission here; copyright rests with the author.

Ubinas’ lavas range from mafic to rhyolitic. She has produced at least two Plinian deposits – the most recent of which occurred between 1000AD and 1160AD, comprising a thick layer of andesitic pumice which was more than 25 cm deep 40 km from the summit. [1,5,6]. Her lavas are sourced from 1) hydration melting (partial melting of the mantle caused by dehydration of the descending slab); and, 2) the mixing of lavas in the feeding magma reservoir. Basaltic magmas from the mantle mix with magmas generated at the base of the crust and in a thickened continental crust [6].

Ubinas developed in two phases: the first phase, Ubinas I, is more than 376,000 years old; and, the second phase, Ubinas II, dates from the mid-Pleistocene. [5,6]

Ubinas I is a low lying volcano with andesite and dacite lava flows. Her SE flank collapsed about 3,700 years ago resulting in debris avalanche flows that extend 12km downstream of the Rio Ubinas. Subsequent eruptions deposited non-welded ignimbrites and pumice deposits. [5,6]

Ubinas II is an andesitic-to-rhyolitic stratovolcano with a summit elevation of 5,672 meters. The caldera at the summit was formed less than 20,000 years ago from Plinian activity. The inner crater is under 200 m high and shows extensive hydrothermal alteration and fractures. Frequent explosive eruptions from the inner crater over the last 10,000 years have led Thouret et al. to suggest that the caldera may be gravitationally unstable. [5,6,7]

Eruptive activity has been documented from 1550. Her most recent eruptions have been moderate explosive eruptions [1]. However, in the light of her history, there is a risk of a something larger.

Hope you enjoyed reading this. The usual caveats apply: “not an expert, etc …”

KarenZ, April 2014

Sources:

  1. GVP: http://www.volcano.si.edu/volcano.cfm?vn=354020#July2013
  2. Buenos Aires VAAC: http://www.smn.gov.ar/vaac/buenosaires/productos.php
  3. “Residents evacuated from homes as Peru volcano spews ash”, 18 April 2014,http://www.bbc.co.uk/news/world-latin-america-27078279
  4. “Peru Evacuates 28,000 Llamas, Alpacas From Active Volcano Area In The South” Published April 19, 2014, http://latino.foxnews.com/latino/news/2014/04/19/peru-evacuates-28000-llamas-alpacas-from-active-volcano-area-in-south/.
  5. Wiki: http://en.wikipedia.org/wiki/Ubinas
  6. Source: http://ovi.ingemmet.gob.pe/portal_volcan/index.php/volcan-ubinas/geologia
  7. Thouret et al., 2005, Ubinas: the evolution of the historically most active volcano in southern Peru., Bull Volcanol, 67, p. 557-589
  8. INGEMMET:http://www.ingemmet.gob.pe/form/plantilla01.aspx?opcion=123#1327
  9. IRIS: http://www.iris.edu/hq/
  10. MODIS sensor heat sources: http://modis.higp.hawaii.edu/cgi-bin/modis/modisnew.cgi
  11. Ubinas, Volcano World: http://volcano.oregonstate.edu/ubinas
Advertisements

92 thoughts on “Unrest Continues at Ubinas 16.355°S, 70.903°W

    • Thank you. It took a couple of attempts at the subduction plot. My first data set was dominated by the current EQ activity to the south.

      Ubinas is active: most eruptive activity is gas emissions with light ash or intermittent ash (using Buenos Aires VAAC as a source). Is she going to do more? – Time will tell.

  1. Video from 15 April of the summit, where a few weeks ago a 120 m lava dome was there is now a gaping hole:

    For comparison from 19 March:

    I wish these guys could navigate quadcopters up there instead of walking on a powder keg.

  2. Spiffing post Karen!
    I must admit I did chuckle to see the news report about moving 28,000 llamas and alpacas – that’s a lot of spit and bad temper on the move. Alpacas, especially, are quite popular round my neck of the woods. Heaven knows why – evil animals!

  3. Lovely night shot of Karymsky recorded on March 27th during an IVS expedition to monitor the volcano and install GPS stations © K. Maguskin

    Layers of ash recorded in this year’s very heavy snowfall around the Raon base near the mountain © K. Maguskin

  4. Wonder if Jamie felt that one?
    Seems like he always misses the earthquakes even though they are just a couple of kilometers from his bedroom.

    • I’m with UKViggen on this one. The amount of heat coming off of a 1000 meter spray of fountaining magma is going to be pretty intense. Especially if the fissure is any where near as long as it was last time.

      I would recommend several kilometers of stand-off and a 1500 mm telescopic lens on a stabilized platform.

      To give you an idea of what we are talking about, here is a scaled representation of the witnessed fountain heights compared to some more well recognized building profiles. The key thing is that most of that magma is going to be over 1000° C.

        • Hi Junior. I wasn’t being serious, really, and a U-2 would be a bit excessive, although the view from FL750 and (redacted) km standoff would be mightily impressive.

          However, I have witnessed what effects a moderate (by comparison with Laki) amount of thermal activity can have on an aircraft (TG would know better than just about anyone), and I know how flimsy UAVs are. It’s not widely known, but a lot of the UAV losses (and I’m talking big vehicles) “in-theater” has been down to them breaking up in the turbulence of thunderstorms. Autonomous cloud detection/avoidance is occupying the minds of a lot of clever people at the moment.

          • Oh boy do I ever know.The Captain I flew with was a LOH (OH-6) Crewman/Observer. in ‘Nam We’d go into a fire and watch 60m old growth Douglas
            Fir explode -“Like a 500 pounder going off.” due to the thermal effects. from the fire.
            It wasn’t unusual to come back with bruises from the shoulder harness due to the turbulence. A UAV would get ripped to shreds. I have great respect and admiration
            for Douglas products….

  5. Dunno what lead up to this… but good aim is all I can say.

    Dunno if it would have fully extinguished it, but it sure as hell would have lessened the chance of it spreading to the foliage.

    • Very very cool. One day in Winslow Az. we were called to put out a very stinky
      pulp wood fire over by Sho-low Az. Seems this pile of Cardboard got a bit dry and self ignited. Lead Plane driver said-” do what you can.” So the Cap’n set up whole
      load salvo. 3000 gallons (about 2X the CL 214) and flew a bit high.No wind, and the
      retardant rains down like a retardant thunderstorm. Result was a stinky,gooey ,pile
      of cardboard. It was fun watching a Newsdroid from Phoenix that night stiking his hand into the gooey mess and losing his watch…
      Now for something completely different:
      http://blog.al.com/breaking/2014/04/watch_spacex_test_its_reusable.html
      Heinlein looks down and smiles…

      • Hopefully, SpaceX will get reusability to work. They went with rockets and proven technology. Most designs that are supposed to be reusable tend to be less orthodox and tested(e.g. Skylon).

        If only congress gave commercial crew more. If they did, US astronauts would not be flying in a Soyuz.

  6. Important Public Safety Announcement

    Lately there have been hacking attempts via mails purporting to be sent by people with Google-mails sending files that are purported to be containing a “bit.ly” shortened link to Google-docs files. This has kind of hit the Dragons hard since we do send each other docs that way from time to time and we often mark it as “Important” and stuff.
    But, the thing is that the link is not a full Google-docs link, it is a shortened link hiding where it redirects to. And the same thing could be used via an ordinary posted link of the “bit.ly” type.
    So, first of all, do not ever click on a shortened link since you will not actually know what page or server it really leads to, and second of all, from now on posting shortened links like “bit.ly” is not allowed on VC for safety reasons.

    So, new rule for your protection, the new rule will be edited in to the very short rules list. And it will be announced on Fridays post, but it is effective from this second, and any Dragon seeing a link like that will immediately remove it.

    “Only full length links are allowed to be posted for security reasons.”

    /The Dragons (sticky-posted)

      • @dinojura44 → It’s a time stamp thing. Dragons have the ability to fiddle with the time stamps and make a post appear in different locations. In this case, think of us as the forum’s time-lords.

        The only reasons that these little quips appear after Carl’s warning, is that they are tagged as responses to it. Hierarchically, they follow it since the parent comment takes priority over time sequencing. But anything on equal footing in the hierarchy can be moved around in time order.

    • Curious, would it be possible for a rift eruption to form north of Bardarbunga as it heads on the fissure swarm north towards Askja? I know this wouldn’t be likely, but just would be interesting to see if it would be a possibility.

      • About one third of the rifting fissure eruptions along Bardarbungas fissure swarm are happening to the north. Among them you have Icelands largest lava field Odhadhahraun. So, theoretically yes, but it is considered that Krafla took care of the rifting eruptions for this cycle.

        • Wouldn’t Krafla be much further north of the Bardarbunga swarm? I was thinking more along the lines of the fissure swarm that runs through Askja. I’m not all that knowledgeable about the Iceland fissure swarms (at least compared to other people here).

          If this were a proper rifting fissure swarm, shouldn’t it be relatively quake-free similar to the dead zone?

          Also, the Hengill & West Volcanic Zone rifts look fairly large, and are attached to fairly large central volcanoes. These rifts don’t seem super active right now. In the past, did these rifts erupt in a similar style to Veidevotn / Laki? Or were they more akin to Krafla with smaller rifting eruptions?

          • Askja is an independent fissure swarm all of its own.

            Let me say it like this, an icelandic fissure swarm is only quake free untill hell opens up, then it gets fairly noisy for a few months.
            Krafla has historically done large rifting fissure eruptions. Hengill has also done large, up to and well above 5 cubic kilometers.

            • Interesting, so why was Krafla’s eruption in the 1980’s so small? Just random variance?

            • If one see the entire series of eruptions in the Krafla Fires as one prolonged eruptive phase then I would not call it small. As such it is the largest Icelandic eruption in the twentieth century.
              The Krafla Fires consisted of 6 fissure eruptions between 1975 and 1984.
              Yes it was smaller than the Myvatn Fires from the same volcano that happened between 1724 to 1746 that also consisted of 6 fissure eruptions. What is also interesting is that the spreading fissure cycle in Iceland seems to start in the north with a fissure eruption at either Krafla or Askja (and rarely at Fremrinamur and Theistareykjarbunga) and about 50 years later you have one south of Vatnajökull. Currently we have ticked off 30 of those years. Not that it is an absolute in any way that we will have an eruption every 260ish years in the dead zone, it has after all skipped one episode from time to time.

  7. First prepare your favourite beans from scratch.
    Then take the meat of half a turkey and fry it. Then blend it with onions and Scottish Bonnet chilifruits and pour that into the beans… Let simmer for an hour or so. Eat. I am just now doing exactly that, and I am in turkey-heaven.
    Just thought that people should know 🙂

      • Well, then you are one of the few who understand. The Catalina channel in California has full blown Asphalt volcanoes but you give an Anti-hydrocarbon junkie a chance and he will blame all of society for there being some sort of hydrocarbon in the “pristine” sea. It’ similar to the Valkyrie fetish among many men. They long for some Ideal Nordic Goddess not realizing that an actual Valkyrie taking an interest in you was not a very good thing. Their task was to select warriors to fill the ranks of the Einherjar.

        • Well you know it only makes sense, because now people think oil is something deeply buried in the ground. It is now, because all the older shallow deposits have already been used (on land). As for the junkies you’re speaking about we have them aplenty on our side of the pond too. They will rant against pretty much anything while knowing very little.

  8. I also have another slightly unrelated rift thought / question. I know we’ve discussed this a bit, but one thing that bothers me about the supposed African superplume theory is this – If there really was a super plume resulting in the east African Rift, shouldn’t we see more uplift instead of intense subsistence due to rifting?

    To clarify for people who aren’t familiar with the debate, the question is about the origin of the east African Rift Zone. This is very much an extremely large-scale “chicken vs. egg” debate with valid points on both sides of the argument.

    -One school of thought is the belief that the volcanism in the east African rift zone came to be as a result of decompression melting as a result of the crust splitting apart into two separate continents. The splitting of the continent eventually created a very large plume, with the plume’s origin being a result of the crust-level rifting. In other words, the plume’s origination is due to a top-down process.

    -The other school of thought which I believe is more popular now is that the rifting on the surface is caused by a superplume which originated extremely deep in the earth. In other words, it’s a continent buster.

    I feel like this would be a very interesting post topic. The volcanic & geologic mysteries are the most entertaining things to me.

    • I will give it a try in a post.
      If you have not seen in it within a couple of weeks or so, just poke me since my memory is a bit sketchy from time to time. I am though pretty convinced I can give a definite answer.

  9. Loloru volcano in Bougainville has begun to show some new signs of activity after the large quake there a few days ago:

    22 April

    “And Mr Lacey says people in South Bougainville have also reported that Mr Loloru, a 1800 metre high volcano has begun to emit steam or smoke. He says they are not concerned at this point but are sending staff to check it out. Loloru is last believed to have erupted 3 thousand years ago.”

    24 April

    “Mt Loloru is near Buin in the south of the main island and where a number of houses were wrecked by earthquakes earlier this month. The provincial disaster manager, Franklin Lacey, says a team delivering basic building materials to the quake victims will include a vulcanologist, who will aim to find out more about activity on Mt Loloru. And he says they are also bringing in three experts from the Rabaul Vulcanological Observatory to help educate the people about volcanoes. ‘We are getting them over here to do some assessment and also some awareness to the people who live beside the active volcanoes here.’ That is the provincial disaster manager in Bougainville, Franklin Lacey. There are five volcanoes in Bougainville”

    • There are actually 17 volcanoes in Bougainville, 6 of them have been active in the Holocene. Bagana is pretty much constantly actively emitting ash, and then you have Billy Mitchell. Loloru reminds of Billy Mitchell, it is a pyroclastic shield blasting out andesite. It has a nested caldera at the top with a andesitic dome and a crescent shaped crater lake.
      If Loloru erupts it will most likely go in the same fashion as Billy Mitchell. One should though point out that Loloru is just the dome poking up though the lake, the volcano is actually named Laluai, a 10x15km Pleistocene caldera. And, not to forget, Loloru has been steaming for about 3000 years now with gracious fumaroles. If it erupts we can probably expect something between VEI-4 and a voluminous VEI-6.
      Neither Loloru or Billy Mitchell is to trifle with.

      • I have always wondered if there was any magmatic relation between Billy Mitchell and Bagana, since the start of activity at Bagana coincided nicely with the last plinian eruption of Billy Mitchell.

      • The volcanoes in this area of the world near New Britain / Bougainville like to do big nasty things it seems.

        This will definitely be an interesting volcano to follow through the next few weeks. I doubt it will fully wake up, but who knows.

  10. First things first: Oh you russians… 😀
    http://voiceofrussia.com/news/2014_04_24/Icelands-inactive-volcanoes-could-erupt-halt-air-travel-expert-5739/

    Whats up with the rising temperature and glacier deformation at Katla? Never heard of that in the past 2 years.

    And second, as for Loloru (and perhaps Billy somewhere down the line), wasnt there something similar at Pinatubo in 1991, where tectonic quakes ended the dormant cycle, or in another words, woke up the volcano? I remember watching a recorded presentation from one of the USGS scientists, saying it.

    P.S. (offtopic)
    The most fascinating volcanoes for me, are anything from Iceland, and globally the over 100 years dormant VEI4/5+ eruptors. The non stop active volcanoes are not really interesting to me. But Loloru is interesting to me. 🙂 But not as interesting as the old Billy boy. 🙂
    How can these volcanoes just go dormant for so long after a long period of much shorter dormant stages? (perhaps another unintentional rhetorical question)

    • I love the fact that volcanoes like Etna give us something to pay attention to almost all the time, but I like most people, the things that are more unknown or the things that can go boom are much more intriguing (that’s just human nature I think).

      “How can these volcanoes just go dormant for so long after a long period of much shorter dormant stages?”

      There are a lot of potential factors to explain dormancy. The first could simply be the fact that the magma supply has shortened. Think of it this way – if a large diapir of magma is slowly intruding into a volcano’s magma chamber and magmatic system at around 20 km depth, depending on the magma type and volcano type, it could potentially support an “active” period of open venting frequent eruptions. Once that diapir dries up or is fully intruded into the primary magma chamber, you may get a long period of no activity.

      Additionally, some volcanoes will tend to plug themself up as they build up their edifice, making it more difficult for effusive magma to escape through the central conduit. This is also part of the cyclical process of caldera formation for more effusive volcanoes.

      As volcanoes get more and more magma and experience more eruptions, they also tend to grow the size of their magma chambers. Each injection & eruption of magma has a small tendency to “stretch” the size of the magma chamber until the chamber becomes unstable, and experiences a caldera eruption. Assuming a constant supply of magma, it’s only normal for a magma chamber to experience longer repose times as it evolves and grows larger due to the greater storage capacity.

      Finally, it’s not uncommon for a deep magma source to migrate between separate areas. The three sister’s volcano in Oregon has multiple edifices and volcanic structures across a fairly large area, but the magma likely all comes from the same deep deep source. If the magma switches to another volcano nearby, it often will result in a long period of dormancy for the other volcanoes in the area (or possible extinction). You can see this process in action currently at Santiaguito, which is a small somma cone that is essentially a parasite at the base of the Santa Maria volcano that had a VEI 6 eruption in the early 1900’s.

      There are other factors as well, such as magma composition, consideration for multiple magma chambers, hydrothermal interactions and more, but these from my viewpoint are the primary factors.

  11. For those waiting for the Riddles…
    Mea Culpa! I wrote a too long piece and lost track of time, bare with me for a little longer and there will be a rather juicy Icelandic post with Riddles. 🙂

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s