From the AGU Geophysical Research Letters: Recent geodetic unrest at Santorini Caldera
Key Points
- Santorini is deforming appreciably for the 1st time since its last eruption
- A dense GPS network has unprecedented data coverage
- Activity is centered in the region that blew-out in the 1650 BC Minoan Eruption
In 1650 B.C.E., a series of massive volcanic eruptions decimated the ancient seafaring Minoan civilization. Over the next 4 millennia, the largely subaquatic Santorini caldera had a series of smaller eruptions, with five such events within the past 600 years, and ending most recently in 1950. From the air, the Santorini caldera appears as a small cluster within the larger collection of Greek islands in the southern Aegean Sea. Following a 60-year lull, Santorini woke up on 9 January 2011 with a swarm of low-magnitude earthquakes.
A GPS monitoring system installed in the area in 2006 gave Newman et al. a stable background against which to compare the effects of the reawakened volcano. By June 2011 the regional GPS stations showed that they had been pushed 5-32 millimeters (0.2-1.3 inches) farther from the caldera than they had been just six months earlier. Following these initial results, the authors bolstered the GPS network and conducted a more extensive survey in September 2011, which confirmed that the land near the volcano was swelling. Continued monitoring from September through January 2012 showed the expansion was accelerating, reaching a rate of 180 mm (7 in) per year.
Using a model that interpreted the source of the deformation as an expanding sphere, the authors suggest that the expansion is due to an influx of 14.1 million cubic meters (498 million cubic feet) of magma into a chamber 4-5 kilometers (2.5-3.1 miles) below the surface. The authors suggest that the ongoing expansion is not necessarily the signal of an impending eruption, adding that the recent swelling represents only a fraction of that which led to the Minoan eruption. However, they warn that even a small eruption could trigger ash dispersion, tsunamis, landslides, or other potentially dangerous activity.
Source: Geophysical Research Letters, doi:10.1029/2012GL051286, 2012 http://dx.doi.org/10.1029/2012GL051286.
Title: Recent Geodetic Unrest at Santorini Caldera, Greece
Authors: Andrew V. Newman: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, USA;
Stathis Stiros, Fanis Moschas, and Vasso Saltogianni: Department of Civil Engineering, University of Patras, Greece;
Lujia Feng: Nanyang Technological University, Earth Observatory of Singapore, Singapore;
Panos Psimoulis: Institute of Geodesy and Photogrammetry, Switzerland;
Yan Jiang: University of Miami, Rosenstiel School of Marine and Atmospheric Sciences, USA;
Costas Papazachos, Dimitris Panagiotopoulos, Eleni Karagianni, and Domenikos Vamvakaris: Geophysical Laboratory, Aristotle University of Thessaloniki, Greece.
Abstract:
After approximately 60 years of seismic quiescence within Santorini caldera, in January 2011 the volcano reawakened with a significant seismic swarm and rapidly expanding radial deformation. The deformation is imaged by a dense network of 19 survey and 5 continuous GPS stations, showing that as of 21 January 2012, the volcano has extended laterally from a point inside the northern segment of the caldera by about 140 mm and is expanding at 180 mm/yr. A series of spherical source models show the source is not migrating significantly, but remains about 4 km depth and has expanded by 14 million m3 since inflation began. A distributed sill model is also tested, which shows a possible N-S elongation of the volumetric source. While observations of the current deformation sequence are unprecedented at Santorini, it is not certain that an eruption is imminent as other similar calderas have experienced comparable activity without eruption.
Any volcanic damage here would be a great shame, it is a truly beautiful part of the world.
Shame the volcano can’t be repositioned under Brussels or Strasbourg………
Well if Greece couldn’t do it with an economic whimper, it might as well try to take out the EU with a bang.
Will there be a lot of underwater sulfurous and CO₂ emissions? A real-world check of the effects of ocean alkalinity decrease in the reasonably-enclosed Mediterranean could yield valuable results. If they can avoid disturbing the aquatic life with further cruise ship sinkings long enough to get uncontaminated observations, of course.
Hmm… and Etna is not so far away.
Watch Katla in Iceland too.
Geothermal.
Next to be outlawed by Obama and the EU.
Etna and Santorini are two different animals. Etna prefers to lazily build up its cone with lava flows, while Santorini is a typical grumbling and occasionally very explosive subduction-related volcano on a par with Krakatau. Added to the mix is the phreatomagmatic violence as seawater and pyroclastic behaviour mix together, making for a mighty big bang. Then the caldera collapses, sucking in a big glut of seawater and creating a final insult, a tsunami which would be a real pain amongst all of those Aegean islands. Meanwhile Etna and Stromboli just splutter along.
GeoLurking can probably weigh in with some fresher takes on it, from eruptions…
http://www.wired.com/wiredscience/2012/03/eruption-update-for-march-21-2012-santorini-nevado-del-ruiz-etna-and-iliamna/#more-101961
Not a lot of new activity, but lots of news of rumblings from different volcanoes worldwide:
Greece
Last week saw a lot of news about a new study that measured inflation at Santorini in the Aegean Sea occurring over the last 5 years. Combine that with the sharp increase in earthquakes, and it all points to magma rising under the famed caldera. The lead scientist on the research, Andrew Newman of Georgia Tech, estimates ~0.14 cubic km of magma has entered the upper part of the magmatic system under Santorini since January 2011 (clearly not an insignificant volume). You can get an idea of the rates and directions of inflation from this animated GIF from the research group. Now, any time a volcano with a legendary eruption like the Thera eruption that may have played a role in the fall of the Minoan empire, you definitely expect hyperbole and hysteria from the media. However, if an eruption happens at Santorini, expect it to be like the eruptions in 1939 and 1950. These eruptions added to the domes in the middle of the Thera caldera – impressive events on their own, but not the cataclysmic event of ~1610 B.C.
Colombia
All eyes are on Nevado del Ruiz right now and much like Santorini, Ruiz appears to be headed towards a new eruptive period. Last week’s Smithsonian/USGS Volcanic Activity Report mentioned “a gas plume rose 1.4 km above Arenas crater, originating from multiple emission sources and thermally anomalous areas within the crater” and the latest update from the Colombian Geological Survey (INGEOMINAS) mentions that the sharp increase in seismicity under Ruiz has continued, with earthquakes ranging in depth from 0.1 to 10 km below the edifice. They also suggest that sulfur dioxide emissions are up, although no values are given. Restrictions have been placed on tourists in the Los Nevados National Park, specifically for the area at the foot of Nevado del Ruiz.
Alaska
Iliamna is also continuing to rumble – and steam. The increased levels of seismicity at the Alaskan volcano has not abated while new pictures of the summit area clearing some a lot of steaming (see above). Both of these signs suggest new magma in the volcano, but so far there aren’t any other signals to say an eruption is very close. AVO has had Iliamna on Yellow/Advisory status since early March, however AVO geologist note that this activity is very similar to another uptick in seismicity and steaming that occurred in 1996 that did not lead to an eruption. The rumblings in 1996 lasted for almost a year before the volcano settled to background activity. You can follow the activity on the Iliamna webcam or webicorder.
Italy
Etna saw yet another paroxysm on March 18 – making it 22 paroxysms since January 2011 and the 4th of 2012. As with almost all the other events, the eruption saw strombolian explosions, fire fountains and lava flows issued from the volcano (see below). With only 2 weeks since the last paroxysm, the interval between is the shortest in the past five months, so when April 1 rolls around, it will be interested to see if Etna keeps up this pattern.
The ONLY variable so far climate, volcanoes, earthquakes etc is the SUN! Its going through unprecedented quiet! To learn more have a look at Discovery Science Channel occasionally
http://www.swpc.noaa.gov/SolarCycle/sunspot.gif
Dalton minimum was also a period of notable volcanic activity.
I’m sure N.Scafetta would also point to the c. 60y recurrence in planetary tidal forces from the Jupiter and Saturn.
Isn’t Santorini the most likely candidate for the fall of Atlantis legends? I remember seeing it on TV.
The Thera eruption caused a 7 meter tsunami 1,000 Ks away at Tel Aviv. With the amount of development along the Med coast, a similar tsunami would have a major impact on lives and property.
Auntie Merkel could not get the Hellenes to mend their spendthrift ways by talking sternly to them, nor by throwing a few hundred billion thalers at them. So she remembered Juno’s words in Virgil’s Aeneid: “flectere si nequeo superos, Acheronta movebo” (VII, 312: ‘If I cannot deflect the will of Heaven, I shall move Hell’).
The Big One (1650 B.C.E) is probably the most famous historically:
“And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night…” [Exodus 13:21].
Boy, that must have been a biggie.
”adding that the recent swelling represents only a fraction of that which led to the Minoan eruption” ?
Now, I may be being a little facetious here, but can someone explain how they can assess the expansion from 1650BC ? – I personally didn’t think the Mionoans were clever enough to have GPS!
Seriously, as a geologist, I simply cannot see how they can assess previous expansion without very detailed geological mapping and cross sections, fault measurements, etc, and even then, using a lot of guestimation! (If anybody knows different, please do tell!)
Its BC not BCE.
I don’t care what C stands for Christ is a greek word meaning “oily”. How anyone can be offended by it I don’t know, but if they go out of their way to take affence then as 1AD was the first year when we had the modern calendar do as I do and take it to mean “before calendar”.
In other words and date (day month) before 1AD (or if you prefer just 1) cannot be calculated using the modern calendar as the two will be out.
More importantly, I used to be an idiot using xxBCE … and xxCE until I read a document from around the first century in a poorly reproduced pdf. I could not tell:
108CE from
10BCE
In other words, if the world for some absurd reason felt compelled to get rid of suffix BC & AD, then the answer is not to replace it with CE BCE because it is just plain daft.
More daft, is why would anyone change “Before Christ” to “Before Christian Era”? …. because there is no such thing as “common era”.
And, I’ve thought about using +109 and -109, but unfortunately the history of the calendar is that the year is counted from a fictional point in time “0AD” and the number refers to the first year before or after this point in time.
So, we come back to the idiotic notion that BC can’t be used because it is religious.
Well what about Monday (moonday),
Tiw’s Day. Tiw, or Tyr, was a Norse god known for his sense of justice.
Woden’sday, Thorsday,
Frigg’s Day. Frigg was another Norse god e
Saturnday, and Sunday.
Here we have Norse and sun/moon worship
What about January (after Janus),
March after Mars,
May after another god
Even August was named after another Roman semi-“god”/emperor augustus.
In other words, time is littered with religious references which we all have to live with.
But don’t we also use names to show respect to those who did the original work? When we publish a picture, we refer to the person who took the picture out of respect for their effort, legally established in copyright law?
Don’t we use names of important scientists on SI units like joules, watt, Newton, etc. Arguably some don’t deserve their name. Newton e.g. stole a lot of his work, and John Harrison who arguably was far more important in creating the modern world through his work on measuring longitude is entirely sidelined by science.
Well, the calendar as we know it was created by Christian scholars, and as a body they chose to use as the reference date their best estimate of the birth of a bricky called Jesus later and universally to christian and non-christian known as “Christos”.
In other words, they deserve the right to have their work respected and for people to use “BCE” which is a completely senseless change which as I said leads to mistakes is completely utterly nonsense.
… and I have just remembered how this makes it so difficult to find any documents dealing with early dates. (“BC” or “BCE” or “CE” or “AD” … prefix and suffix and B.C.E. and B.C. and BC. and …. I forget all the numerous combinations”) The British seem entirely unlikely to change from BC/AD … largely because it was a British churchman who invented it … and even if we did change, so many old documents use the system that without literally rewriting history it will always remain.
All I would ask is that:
1. BC and AD are used as suffixes.
2. They are not abbreviations … they are units like mm (not m.m.)
3. Anyone who finds “Christ” objectionable … just replace it with “Before Calendar” … but it’s meaning does not matter
4. AD …. it’s some objectionable latin phrase. … personally I’d prefer it were different, but I would also call the Newton the Harrison … but if everyone were as daft we’d none of us understand each other and as I said. The christians did some good early work and do deserve the credit.
i think that there is a connection with the earthbreak of Sicily in the last week…
Scottish Sceptic says: April 17, 2012 at 1:08 am
No it isn’t. Since your second sentence is wrong, is it worth reading the rest?
Oh dear, it’s getting a bit heavy! Well, Greece certainly has had it bad, worst economic crisis since the end of WW2. The German dominated EU is piling on the pressure for austerity & I think the Greeks are losing their grip! An earthquake or volcanic eruption might just take their minds off their troubles. As to Christ being a Greek word meaning “oily”, I think you’ll find that the interpretation of that literal translation was meant as “Anointed one”, but I’ll let the theologians squabble over that one. However as I Christian of sorts I dare say I will be ravaged & made to feel sinfull & guilty, all part of the Agenda 21 subtle systematic destruction of Western Free Enterprise culture I expect! After all, everyone takes offence except us, we just quielty get on with our lives, if we’re allowed to, that is !
Anyway, in light of all that, here’s a giggle doing the rounds:-
Angela Merkel arrives in Greece. Immigration Officer asks, “Name?”, Merkel says, “Angela Merkel!”, Immigration Officer asks, “Nationality?”, Merkel replies, “German!”. Immigration Officer asks, “Occupation?”, Merkel replies, “No, I am only here for a few days!”
Apologies to all my lovely German friends, they have a great sense of humour 🙂
There model assumes an expanding sphere and this is used to estimate the volume of magma. It seems to me that it should be a half sphere at the top of a column that cuts through the Earth’s crust. If it were an expanding sphere, it would be pushing out horizontally in all directions deforming the crust in more ways.
Their model…
That CO2, it gets everywhere.
steveta_uk said on April 17, 2012 at 1:27 am:
http://en.wikipedia.org/wiki/Anointing
So it’s oil covered, like a salad or olives and with a good oil, not “oily” like the bottom of a car engine or a WWF rep asking for a donation to save polar bears threatened by Mann-caused globe-bull warming.
Can we declare a peaceful agreement on this?
“TheBigYinJames says:
April 17, 2012 at 12:24 am
Isn’t Santorini the most likely candidate for the fall of Atlantis legends? I remember seeing it on TV.”
The Atlantis legend (singular) comes from about half a page of Plato’s ‘Republic’. All the modern guff owes it’s existence to Ignatius Donnelly. You might take the view that “It must be true, I saw it on TV”, but then again…
For what it’s worth, my guess, if there is any reality behind Plato’s account at all, is that the destruction of Atlantis harks back to the re-flooding of the Black Sea in about 5600 BC (Well said, Scottish Sceptic!). It’s in the right area and there are two rocks at the Northern end of the Bosporus which would do very well as the “Pillars of Herakles”, mentioned in hte Argo legend and pointed out by Tim Severin in his book (and TV programme) “The Argo Voyage”, wherein he re-traces the legendary route of Jason to Colchis (modern Georgia).
@ur momisugly Ed Mertin April 17, 2012 at 12:04
Etna continues to rumble. New paroxysmal eruptions occurred on April 1 and April 12
http://en.wikipedia.org/wiki/Mount_Etna