Santorini: Is this volcanic activity?

This

"The team, from Durham University and the University of Leeds, studied crystal formation from a volcano, in Santorini, in Greece, to calculate the timescale between the trigger of volcanic activity and the volcano's eruption."

is a small quote from here

www.sciencedaily.com...

Sorry for brevity, but it's late and I have to be up at 5am!

Rainbows
Jane

reply to post by angelchemuel


That's a pretty cool discovery in that article. The key part being:

By studying the area between the crystal core and the rim the team then worked out how long the rims had existed – revealing how long the magma was in the shallow chamber before it erupted.

The crystals showed the 1925-28 eruption at Nea Kameni took place three to ten weeks after the magma entered the shallow system.

As magma movement typically causes seismic activity, if any future seismic or inflation activity at Nea Kameni can be linked to magma recharge of the volcano, the scientists predict an eruption could follow within a similar timescale.

They hope this method can be applied to other volcanoes, allowing the pre-eruption behaviour to be better understood - and understanding of volcanoes to be extended back further in time.

A problem with this methodology imo is that you don't know to what degree the deep conduits remain constant after the last eruption, and also, how much magma is entering the system down deep. Different pressures would arise from a different magma composition, and also from a different quantity of it. And plus, the cap(s) would be different, affecting the eruptive process too.

But still, since each volcano is unique, pinning down its eruptive process over a long time helps, so it's a worthwhile effort for the long haul. With a little luck and a lot of effort, in two hundred years from now they might have well monitored volcanoes that are caught erupting with modern instruments a lot better figured out. Although if they happened to catch a supervolcano like Toba erupting bigtime, dunno if it's going to matter much. Cause it could be the end.

Here is a link to a 3D vid of ground deformation on Santorini

www.youtube.com...



rainbows
Jane

reply to post by PuterMan


Hi Everyone,

I'm very glad about the feedback on my reply to the main post about Santorini.

As I mentioned before, we're checking the earthquakes, but also a "real time seismograph", which is available under this address:
www.geophysics.geol.uoa.gr...

This is the Real-time seismogram from station in Neapoli (located 12 km west from Agios Nikolaos). I have to admit here - it's a pretty good one, that really shows what is happening here.
We're concerned especially about those magma movements - if You check the website, You'll know what I mean and probably many of You might agree. We checked also the archives and I have to say it wasn't so "alive" even one year ago. Of course, there were days with some bigger activity, but what is happening since the end of May may really bring some concerns on our daily life. Almost every day there is at least one, rather small quake, but still we can feel it - the monitor is shaking every time it happened.
Although, I have to admit it's more quiet now these days ...

I would also like to mention here, on this forum, but I read already a few others, about those strange like-underground booms. We never heard them before, just from around the 30th May. Very, very strange ...
I read it's some kind of phenomenon going on in different parts of the world, but no one can actually say/write sth more about it.

We're glad to "hear" from others some responses, because those people here are really strange ... The moment we told them about these earthquakes and showed them where actually they happened (literally, under their as..s) they seemed to not get anyth from it - no concern, no fear, not even interest!!! (I'm talking here about Cretans). If You would ask them what they know about the Lake Voulismeni and it's volcanic "roots", You might see ONLY "?" on their faces.
Anyway, we're really happy about the feedback and interest. From which ever point we look at this "problem" - because it IS one - it's very important that Others write and leave their feedbacks too!

reply to post by AgiR83


Thank you for keeping us updated.
May I ask, just as a point of clarification, you write as though you have direct access to the information you are providing here. I don't mean just looking at various seismic websites, you write as though you are directly involved with collecting and analysing the data. Is your work in this field?

Rainbows
Jane

reply to post by angelchemuel


Gee 'Rainbows' that find warrants another few thousand stars.

It would be good to see the progression since then. 5cm** (50mm or about 2 inches) may not seem much, and if it is just the volcano 'breathing' may not come to much but what interests me is that the deformation is to one side of the island suggesting that they may be increased deformation under water.

** From the link at the bottom of the post.

Since January 2011, earthquakes have shaken the landscape and the Santorini volcano’s surface has lifted by about 140 millimeters

Chasing a bit further along the links I find this from ESA (The European Space Agency)

Seismic activity in Santorini, such as the underground movement of magma, from January 2011 to today has caused ground deformation that was detected by Envisat’s radar.

Even from an orbit about 800 km above the ground, deformations of a few centimetres can be detected by satellite radars.

When two or more radar images of the same area are combined, changes in signal reflections between them can be measured. This technique called Differential Interferometric Synthetic Aperture Radar – or DInSAR – has become a useful tool for detecting ground deformation.

Envisat shows that the northeastern part of Santorini’s Nea Kameni volcano experienced an uplift of about 5 cm in 2011, while other areas of the volcano rose some 3–4 cm.

"Monitoring to detect any change of the status of the volcano presents a further step towards the understanding of physical processes related to volcanic eruptions that can lead to natural disasters," said Prof. Issaak Parcharidis from the Department of Geography at the Harokopio University of Athens.

During the first months of this year, Santorini saw a drop in the speed of deformation, accompanied by a reduction in seismic activity.

"After evaluation of local seismic activity, deformation and physicochemical changes, [we] concluded that during the last months the volcano presents a very limited activity, much lower than that of 2011," said Prof. Kosmas Stylianidis, Head of the Special Scientific Committee for the Monitoring of Santorini Volcano.

Follow the link above for more details.

Just a sentence below however is this worrying snippet of information:

Contact with Envisat was lost on 8 April

Let's hope they get a replacement up there soon!


I have just found evidence of the GPS measurement ON Santorini which is good news.



Source: Science News: Greek Volcano Awakens

reply to post by AgiR83

We're concerned especially about those magma movements

I have to say that, assuming we are talking about the quakes in your area, I can't see any instrumental evidence of harmonics from the one I can get data for or anything that would suggest magma movement. Let me also say that I am not on the ground there as you are so you may have a better take on this.

The archive, taking 2 plots completely at random, would seem to suggest that this kind of activity is normal at least in 2012.

January

March


What I do find quite interesting is the increase of magnitudes currently showing across the southern areas of Greece and you progress from West to East and get to Turkey.



I would also point of that like so many seismos in Greece it seems this one to which you are referring is not exactly site in what i would call an ideal location!



To have that seismo cluttered with cultural noise is inescapable.

just on dutch msm

www.nu.nl...

Magma pushes up Greek island


SANTORINI / LONDON - The Greek island of Santorini on volcanic rock hopes. This is the island still slightly higher above sea lie.

Photo: Reuters

According to a study by British scientists, that Sunday was published in the science journal Nature Geoscience.

Between January 2011 and April 2012, Santorini thus 14 centimeters higher above sea come to lie.





According to British scientists there in over a year time 10 to 20 million cubic meters magma from deep layers of the earth, streamed into the volcano . Normally there 10 to 20 years to.



next eruption


The researchers also see the inhabitants of the island, the volcano behaves differently. Yet they can not predict when the next eruption.

Santorini, a tourist attraction, is a volcanic island. The last major eruption was 3600 years ago. The surrounding islands were then buried under meters of pumice.