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.
Look !
if we are going to control the Earth`s climate in the very near future then just putting one small volcano permanently out of action should be childs play, a sort of `proof of capability` before we go on to great climate thing. I didnt see them suggest a modus operandii.
regards
(sarc)
Joe Zarg says:
April 17, 2012 at 4:08 am
“If you do not want to cater to your audience, close the blog.”
One can only hope that this is, in some obscure way, sarcasm.
Allan MacRae says:
April 17, 2012 at 6:15 am
Heck Allan – you must be good at holding your tongue? At the very least, I would have had to stand on a chair and tell them I was being sarcastic, and that only an idiot would equate volcanic activity to global warming! (then I’d have watched them admit idiocy or squirm!)
Jeff Norman says:
“Their 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. “
The model in question is the Mogi model. (Kiyoo Mogi). It’s a simplified model, and there are more advanced ones that assume cylindrical chambers (vertical or horizontal orientation) but the Mogi model is comparatively easy to calculate. The other benefit of the Mogi model is that it tends to be a pretty good estimate of what is down there.
When you are trying to get a handle on how much of the melt is available, and then tally up all the stuff that comes out so you have an idea of how big one eruption is compared to another… well, the Mogi is accurate enough.
http://www.geophys.uni-stuttgart.de/oldwww/ew/volcano/node8.html
Scottish Sceptic says:
April 17, 2012 at 1:08 am
All I would ask is that:
1. BC and AD are used as suffixes.
But (to use your words) in the objectionable Latin shouldn’t AD be a prefix?
A Mexican volcano is stirring as well, I read this morning.
http://news.yahoo.com/mexico-raises-alert-popocatepetl-volcano-091647845.html
P. Solar says:
April 17, 2012 at 12:15 am
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.
We calculate the earth’s tides using a very similar mechanism to that used to calculate horoscopes. The result is much more accurate than the result given by calculating tides based on gravitational forces.
Yet, given the success in calculating tides in this fashion, supposedly learned scientists then reject this technique to calculate other events that could also be affects by tidal forces. Such as climate cycles and volcanic cycles.
The problem is that scientists in general, and US scientists in particular are prejudiced over the use of the term “Astrology” and use it as a term of insult. As a result they throw out the baby with the bath water.
Here is what wikipedia says about astrology:
While astrology may bear a superficial resemblance to science, it is a pseudoscience because it makes little attempt to develop solutions to its problems, shows no concern for the evaluation of competing theories, and is selective in considering confirmations and dis-confirmations.
This could just as easily be written as:
While AGW may bear a superficial resemblance to science, it is a pseudoscience because it makes little attempt to develop solutions to its problems, shows no concern for the evaluation of competing theories, and is selective in considering confirmations and dis-confirmations.
All I have to say is that the vast diversity of knowledge shown by the commenters on this site is what keeps me coming here. Add to that the absolutely brilliant wit, as shown by Alan the Brit’s Merkel joke, makes this the site I must visit regularly every day.
Peter Kovachev says:
April 17, 2012 at 3:47 am
Scottish Sceptic says:
I think there ought to be some respect given to the historical perspective. Thus, I find the date issue to be in the same class as a Liverpool councillor suggesting renaming “Penny Lane” . . .
“Penny Lane recalls the 18th-century slave trader, James Penny. Possible substitutes included homages to those who worked for the abolition of slavery, including William Wilberforce, or a tribute to the black teenager Anthony Walker, murdered in a racist attack in the city last year.
http://www.independent.co.uk/news/uk/this-britain/labels-the-name-game-408113.html
. . . and “planetary wrath and ridicule” followed. Christ Church, Nashville/ Christchurch, NZ / and on and on … ???
In the USA, we could rename anything and everything now known as “Washington” to “John” (my preference) because George was a slave owner.
————————————————————————–
Back to the Volcano
http://www.nytimes.com/1985/12/24/science/new-find-is-linked-to-events-to-exodus.html
PROBING 20 feet into the soil of the Nile delta, American scientists have found tiny glass fragments from a volcano that they say could lend support to a theory linking a volcanic eruption to the seemingly miraculous events associated with the Exodus of the Israelites from Egypt.
This isn’t a new idea, they just found some new evidence (1985).
The Greek fire comments above remind me of Pratchett’s Discworld where a tourist from the counterweight continent inadvertantly causes Ankh-Morpork to burn down after introducing the concept of a fire insurance policy.
Dave (UK) says:
April 17, 2012 at 4:14 am
“As an aside. In response to several comments about the calendar, perhaps it is time we migrated from the Gregorian Christian calendar to something more meaningful. Here’s my starter-for-ten for Day 1:
* Industrial Age (start of the industrial revolution – in a cotton mill in Manchester, England, if I remember rightly),
* Electromagnetic Age (Faraday’s discovery of electromagnetism),
* Atomic Age (but should it be discovery of radioactivity, atomic power, or atomic weapons?),
* Space Age (first orbital device, rather than first human into orbit).”
Do you promise we will not lose another 11 days?
Tried to find the subject in the Greek news, and it is way down , the last date something was published was March 15, discussing the article you have posted.
It says that 90% of similar calderas do not errupt after similar behavior.
This link is in Greek.
Assuming the oceans were much lower in 1600 BC, the caldera is going to react differently should there be a super eruption. Either way, might be best to watch from another planet. Food storage might be in order…. for lots of reasons. 🙂
Would be interesting if global volcanism was cyclic, I would imagine that the velocity of plate movement would be a factor.
“Hutch says:
April 17, 2012 at 7:19 am
Scottish Sceptic says:
April 17, 2012 at 1:08 am
All I would ask is that:
1. BC and AD are used as suffixes.
But (to use your words) in the objectionable Latin shouldn’t AD be a prefix?”
I believe it could be either prefix or suffix as AD, in the latin, Anno Domini, in english, “the year of Our Lord”. BC, before Christ. He must have had some significant impact upon the world, as I am not aware of anyone else’s birthday being used to begin and end the counting of time for such a large part of the world’s population. Jewish calendar? Chinese calendar? Anyone familiar with their basis? Don’t make me go to wikipedia!
Also have not seen a post to reply to the comment re how we know what the expansion rate of the magma dome of Santorini was in 1650 BC, in order to compare it to today? Great question!
Also of interest is after the two 8+mag quakes west of Sumatra, each day now we’ve seen stronger quakes(6+) in others places. Kinda think those 8’s weakened some faults. Japan is still dealing with moderate to sometimes strong quakes long after that 9 hit over a year ago. Very unstable ground still.
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/quakes_all.html
If I lived on the West coast, I’d be getting a bit nervous. Especially after all those big Mexican quakes. Adjustments in the faults there could be putting more pressure on the CA faults.
Chuck Nolan says:
April 17, 2012 at 6:18 am
ChrisM says:
April 17, 2012 at 3:16 am
“Perhaps they have set fire to Greece to claim on the Insurance………
—————————-
The Greeks hired the Italians to cause a big fire but make it look like an accident”
You had best see the movie,”Kill the Irishman”, before you make comments like this one! Good movie and historically accurate.
John F. Hultquist says:
April 17, 2012 at 8:06 am
(Peter Kovachev says: April 17, 2012 at 3:47 am)
…I think there ought to be some respect given to the historical perspective. Thus, I find the date issue to be in the same class as a Liverpool councillor suggesting renaming “Penny Lane”…
And I find this issue is getting to be a tad silly, John. How would my preference in using BCE/ACE disrespect “the historical perspective”? Or threaten to rename Penny Lane or Christchurch, perish the thought? I use BCE/ACE only whenever I write to a Jewish audience or in an academically-leaning forum with educated readers, such as this one, where I can assume to be among peers with education and to be safely in the lee from from red-neckery and bloody-mindedness. Otherwise, the run-of-the mill עם הארץ or the οἱ πολλοί get the BC-AD bit, so consider yourself honoured.
* Industrial Age (start of the industrial revolution – in a cotton mill in Manchester, England, if I remember rightly),
* Electromagnetic Age (Faraday’s discovery of electromagnetism),
* Atomic Age (but should it be discovery of radioactivity, atomic power, or atomic weapons?),
* Space Age (first orbital device, rather than first human into orbit).
Any one care to extend the list?
================================
* 2nd Age of Migrations (a global uptick in volcanism on the heels of a Maunder Minimum triggers global thermonuclear war).
Roger Carr says:
April 17, 2012 at 4:13 am
Alan the Brit: “No, I am only here for a few days!”
Brilliant, Alan!
I hasten to add, it was a joke I saw somewhere else, it was not mine, it just appealed to my sense of humour! 😉
“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.”
So, if I’m following the bouncing ball properly, instead of properly studying the volcano and its caldera for evidence of change the researchers felt/saw the ground move. Its all about people these days : P
Thankfully we don’t approach it this way — http://www.avo.alaska.edu/activity/index.php
Just because Santorini is inflating does not necessarily mean that it is going to reprise the 1650 BC caldera forming eruption. The Smithsonian Global Volcanism Program lists over a dozen historic eruptions since the Minoan destroying eruption. The duty cycle on this one appears to be pretty long (fortunately) with over 3600 years since the last huge eruption – which depending on the tightness of your (or my) tinfoil hat may or may not mean we are due. Other dangerous mountains like St. Helens or Krakatau have much shorter duty cycles. Krakatau went only 1300 years (or so) between its huge blasts in 535 AD and 1883 AD. Even Yellowstone has been active since the last big blast 600,000 years ago. We tend to focus on the really big eruptions and forget that stratovolcanoes / caldera systems need to have a series of eruptions to rebuild the next cone or dome or other structure for the next big blast to destroy. Cheers –
http://www.volcano.si.edu/world/volcano.cfm?vnum=0102-04=&volpage=erupt
David Jones says:
April 17, 2012 at 8:30 am
* Atomic Age (… atomic weapons?),
A(tomic) A(ge) or After Hiroshima was sporadically used in Astounding Science Fiction after 1945. If memory serves, that stopped around 1949. The last time that way of dating was used was in the title of a German SF novel: Rochard Hey’s “Im Jahre 95 nach Hiroshima” (In the Year 95 after H—, 1982). Which, by the way, depicts Europe in the iron grip of an ice age.
As far as Volcanoes go I’d much rather have Etna and Stromboli in my back yard-than
Santorini or Ranier ( or Glacier Peak.)- the latter two are in my back yard..
For a long time I have wondered if rapid oscillations in the Earth’s magnetic field could be contributing in a small way, smaller than radioactive decay, to heating of ferromagnesian minerals by magnetically induced eddy current losses.
Peter Kovachev says:
April 17, 2012 at 9:50 am
John F. Hultquist says:
April 17, 2012 at 8:06 am
(Peter Kovachev says: April 17, 2012 at 3:47 am)
…I think there ought to be some respect given to the historical perspective. Thus, I find the date issue to be in the same class as a Liverpool councillor suggesting renaming “Penny Lane”…
And I find this issue is getting to be a tad silly, John. How would my preference in using BCE/ACE disrespect “the historical perspective”? Or threaten to rename Penny Lane or Christchurch, perish the thought? I use BCE/ACE only whenever I write to a Jewish audience or in an academically-leaning forum with educated readers, such as this one, where I can assume to be among peers with education and to be safely in the lee from from red-neckery and bloody-mindedness. Otherwise, the run-of-the mill עם הארץ or the οἱ πολλοί get the BC-AD bit, so consider yourself honoured.
=========
..you have your own calendar, why not use that when writing to a Jewish audience? If I recall, and it is rather a long time since I took part in discussions about G-D, BCE/ACE variation came from the Jews who tend to get apoplectic whenever Christ is mentioned and the common use of BC/AD offended them because they knew what it meant.
Far too many ‘politically correct’ adjustments have been given credibility mainstream, it’s so very tiresome, but this variation is less irritating than some. It amuses me that after the contortions of ‘chairperson’ via ‘madam chairman’, they appear to have settled on ‘chair’.
I wish they’d agree what a billion was. How can we tell how much of tax payers money is being ripped off otherwise? There’s a heck of difference between a million million and a thousand million and we’re now into trillions. http://en.wikipedia.org/wiki/Long_and_short_scales
When was the big bang?