Wednesday, January 16, 2013

Indonesia Volcano Seulawah Agam Rumbles, New Solfatara Forms

Indonesia is one place on the planet where active volcanoes are simply a part of life. With more volcanic activity than virtually any other place on the planet (at least above water), and more concurrent active volcanoes than any other nation, it typically doesn't make for great volcano blogging to mention the obvious, that some volcano in Indonesia with a hard-to-pronounce-name is erupting. But this week's Smithsonian GVP report caught my eye in regards to one Sumatran volcanoes rumblings.

Seulawah Agam volcano, one of the Northernmost volcanoes in the Indonesian archipelago has apparently begun to rumble. This volcano is of interest given that it has no 'confirmed' reports of historical eruptions, however this is uncertain. An eruption was reported int he 16th and 19th centuries, but no evidence has been found such as tephra layers, or any obvious lava flows that correspond to these dates. One theory posited by the GVP is that those mentioned eruptions could have been phreatic (water/steam driven) rather than magma related, which would make the eruptions very brief, and much less destructive.

However the nature of this volcano could change, as it is now becoming clear that magma is entering  the system. New solfataras (cracks that emit sulphurous gases and water vapor) have opened, and deformation is occuring. This means that if the volcano is going to erupt, it won't simply be a small phreatic eruption this time, and given the fact that we just don't know the last time it erupted, it could be a lot bigger than some of the normal eruptions in Indonesia.

More interesting still, it is located at the Northern tip of Sumatra, which has not experienced a whole heck of a lot of historical eruptions. It could be that the subduction of the plates underneath coupled with the recent spate of very large (7.0-9.1 magnitude) earthquakes has generated more fuel for the various magma chambers in the area.

Indonesia site on the Pacific Ring of Fire, which 'rings' the Pacific ocean with volcanoes. The bulk of these formed as a result of subduction, where one plate slides under another, creating magma through intense friction, heating of water at high pressure, and eventually creating a magma conduit to the surface. Most volcanoes that form on this subduction zone, like Seulawah Agam, are 'stratovolcanoes', which typically form into large, conical structures that look very much like our typical idea of a volcano.

This volcano, should it erupt (it is always possible that nothing will happen, as many magama intrustions do not result in an eruption at all!) has the potential to generate large explosions, heavy ashfall, pyroclastic flows, lahars, and other dangers to the surrounding population.

Here is the exact statement from the Smithsonian:

"SEULAWAH AGAM Sumatra (Indonesia) 5.448°N, 95.658°E; summit elev. 1810 m

CVGHM reported that visual observations of Seulawah Agam during 27 December-2 January seismicity increased. Visual observations were prevented due to fog, although on 2 January scientists observed a new solfatara that produced roaring noises and was within 20 m of van Heutsz Crater on the NNE flank. The Alert Level was raised to 2 (on a scale of 1-4) on 3 January. Geologic Summary.

Seulawah Agam at the NW tip of Sumatra is an extensively forested volcano of Pleistocene-Holocene age constructed within the large Pleistocene Lam Teuba caldera. A smaller 8 x 6 km caldera lies within Lam Teuba caldera. The summit contains a forested, 400-m-wide crater. The active van Heutsz crater, located at 650 m on the NNE flank of Suelawah Agam, is one of several areas containing active fumarole fields. Sapper (1927) and the Catalog of Active Volcanoes of the World (CAVW) reported an explosive eruption in the early 16th century, and the CAVW also listed an eruption from the van Heutsz crater in 1839. Rock et al. (1982) found no evidence for historical eruptions. However the Volcanological Survey of Indonesia noted that although no historical eruptions have occurred from the main cone, the reported NNE-flank explosive activity may have been hydrothermal and not have involved new magmatic activity."

Wednesday, January 9, 2013

Campi Flegrei Inflating Again

The massive Campi Flegrei caldera, one of a few large and active caldera systems in the world, seems to be inflating at an accelerated rate, and new data suggests that it is also heating up. Volcano-discovery.com reports that the area has been uplifted by an astonishing 8cm during their study period of July-August of 2012, until now, and that the uplift seems to be holding steady. Even more disconcerting is that gas emissions and fumerole temperatures are also on the rise.

Volcano-discovery.com cites this Italian goeology journal as the source.

Campi Flegrei's last eruption produced the Monte Nuevo cinder cone during the year 1538 A.D. While this was not a very large eruption, a similar eruption today would find itself in a very densely populated area, where it would be extremely difficult to evacuate everyone (scenes from that horrid movie "Volcano" with Tommy Lee Jones comes to mind), and damage to life and property could be severe.

While it is far, far too early to begin ringing alarm bells, lets keep in mind that many of Italy's famed eruptions have resulted in fatalities on massive scales before. When Mt. Vesuvius erupted in Roman times, it completely wiped out the cities of Pompeii and Herculaneum. Little warning was issued by the volcano, and the sudden onst of ashfall and pyroclastic flow gave people little or no time at all to escape the doom. Preserved in pyroclastic flow, the bodies were later unearthed in exactrly the positions they were in when the pyroclastic cloud swept over the terrified city.

An eruption today, from virtually ANY mainland Italy volcano could even be worse. However, given that volcanologists and geologists exist today, we have a slight edge, and therefore should be able to at least give a couple hours of warning before any main event.

The other issue with attempting to identify risks of Italian geology is the Italian government itself. Late last year, several italian scientists were convicted for manslaughter for 'failiing to predict an earthquake'. It seems the Italian government puts more faith in calirvoyance than good science, and unfortunately, if an eruption were to occur and there was loss of life and property, it is likely (now that there is precedent) that the Italian government would again attempt to hold scientists responsible for an 'act of god', so to speak. Truly insane if you ask me. It would be like suing the weather man for every time the wind shifted.

In any case, check out Volcano-discovery.com's article on the goings-on at this fascinating, yet slightly terrifying volcano.  

Monday, January 7, 2013

What's Ahead for 2013?

The year 2012 was a pretty wimpy one, volcanically speaking of course. About the biggest (and most spectacular) eruptions occurred from the 'usual suspects' (Kilauea, Etna, etc), and really only a couple of eruptions happened that were noteworthy at all. Tolbachik in Kamchatka, Russia has put on arguably one of the most stunning displays of fissure activity, while Kilauea and Etna keep on proving that you can't take your eyes off of them for any real length of time. But other than that, there were no eruptions whatsoever in Iceland (unless you count some very minor hydrothermal/Jokullhlaup activity), barely a puff from Cleveland volcano in the USA, and really nothing terribly unusual. 2012, for all the hype about volcanic disasters, was actually one of the calmest years for eruptions in recent memory.

But waht will 2013 portend? While predicting eruptions is definitely a silly thing to pretend to do, there are some volcanoes that are expected to be way 'overdue' for an eruption (as if volcanoes check out our schedules and adhere to them).

Katla, Iceland.

it has long been suspected that there is some sort of link between Katla and its smaller neighbor Eyjafjallajökull, however the theory is beginning to look like a dud, as it has now been over two years since Eyja erupted, and despite some rubling and weak deformation from Katla, it has remained mostly silent and stable. But this could change quickly, as Katla typically erupts about every 50 years - and its last eruption was over 60 years ago now. Scientists, and bloggers alike are watching this volcano closely.

A large eruption from Katla has the potential to be quite devastating for Iceland and Europe, as it is known to produce large ashfall zones, and emit many hundreds of thousands of tons of sulphur dioxide gas (SO2), which some scientists say can be larger in amount than the famed 1700's eruption of the Laki fissure system, which was quite damaging to Europe and has even been cited as one of the catalysts for the French Revolution. An eruption today would devastate Europe, and possibly Russia, and North America with noxious clouds of SO2.

Hekla, Iceland

Hekla has long been thought to be overdue for a much larger eruption than we typiclly see. Indeed, when looking at ash layers, and craters, you can see that Hekla has produced much, much larger eruptions in the past than are historically recorded. Hekla last erupted in 2000, but has since been relatively quiet. This volcano is not typically known for giving much advance warning.
Vesuvius, Italy

While most people think of Vesuvius' massive Plinian eruption that destroyed Pompeii as the last time the volcano erupted, it was actually active as recently as WWII. Since then, people seem to have forgotten about the sheer might of this monster volcano, and the lesson from Pompeii. Vesuvius towers over the city of Naples, and many geologists say that the volcano could be primed for an eruption at any time. While it is impossible to say when or if it will erupt, many scientists and geologists (especially ones in Italy who are now apparently accountable for failing to predict geological events...) are watching Vesuvius with nervous anticipation of it's next move. Will it blow in 2013? Nobody can say.

Santorini, Greece

For about two years now, the massive Sanotrini caldera, and neighboring Kolombos volcano have been showing signs of unrest. from increased underwater fumerolic activity at Kolombos, to a massive inflation of the magma chamber under Santorini, some suspect that this area is also ready for some eruptive action. But don't worry... while both volcanoes are indeed active and have a history of some major eruptions, those major eruptions are so geologically recent that it is unlikely (if not impossible) for either volcano to top their 'greatest hits'.

If an eruption at Santorini were to occur, it would probably occur on its central island/lava dome of Nea Kameni, repeating past events like the ones in the 1950's. Effusion of lava/lava domes, and small ash producing explosions. While this could upset tourism on the island, it would pose very little danger to people, and they would most likely have plenty of time to evacuate if it were deemed necessary.

Scientist are watching the area cloasely for any swift deformation, and harmonic tremor, which would likely indicate something is getting ready to happen.

Alaska (Aleutian Islands)

While Alaska's Aleutian islands are usually a hotbed for volcanic activity, containing some of the most active volcanoes in the United States, 2012 was a relatively calm year with only Cleveland Volcano producing any real activity. Two other volcanoes, Little Sitkin, and Illiamna, have rumbled away but did not produce any eruptions. Typically, there are 1-2 volcanoes erupting on the aleutian peninsula in a given year, sometimes more. The remoteness of the islands, lack of equipment, bad weather, etc all make monitoring these volcanoes a bit difficult for the USGS, but it would not surprise me in the least to have some big earthquakes (A 7.5 mag quake occurred today off the Southern coast of Alaksa) and a couple volcanoes erupt (Cleveland, probably will continue its cycle, and I am watching a couple others that seem to be rumbling a bit more than ususal).

Cascades Rangs, West Coast, USA

While the last volcano to erupt on the West Coast of the US was Mt St Helens (which completed its last eruptive cycle in 2008 with the extrusion of more lava dome material), there are several other volcanoes to really keep an eye on. Mammoth Mountain has shown some increased seismicity, and the area of suspected magma dike intrusion/tree kill still emits heavy concentrations of CO2. Mt. St. Helens is definitely always worth watching (as history shows). Lassen Volcanic Center has not had an eruption since 1913, but recent seismicity tells us not to take our eye off of that area. Shasta is always a nervous volcano to watch, and Rainier could defnitely surprise us.

I could go on forever about which volcanoes to watch (I say watch them all!) but truthfully, anyone who would claim to predict the future of eruptions in the world is not worht listening to. Instead I will quietly hope that 2013 brings some awe inspiring (and non-deadly) eruptions for our vieweing pleasure. 2012 was just not that great for blogging!