Santorini Earthquake Update 21.2.25 – Water-Magma
Activity is continuing downwards with energy released also down. Energy released is coming into the range of what would be called normal but the number of quakes being recorded is still over 500% above the norm. In today’s Santorini earthquake update we’ll look at island movement over the past two days, visit the Anydros seismic station and then have a look at what some professional geologists are saying at the moment.
Links to live earthquake data and information sources.
Cumulative Energy Released
Volcano discovery provides the daily graphic and it shows intensity dropping back to the norm
Seismic Locations
The epicentres are back surrounding Anydros. I think at this point, if someone were to say Anydros is the centre of this swarm and perhaps even the key to understanding what is happening and could help us predict the next few days, I would agree with them.
Seismic Data Anydros
With regards to line roughness or “underlying seismic activity”, I’d say we are about where we were yesterday. But there is a noticeable uptick in spikes, events which may register as an actual quakes. I think normally we would expect these lines to be completely flat most of the time and for sure not as many spikes on a normal day prior to this latest swarm. I would say something is still going on, question is what and where will it lead?
Ongoing Light Seismic Activity – Anydros
What would ongoing seismic activity (not registering as an earthquake) signify? Bear in mind I am a layman, I think it could be reasonable to expect that it is magma movement. Magma moving through channels in the crust relatively easily because these channels are now devoid of water due to the heat of the past 2 weeks. re Geology Hub video, link below.
We have reduced earthquakes, we have reduced intensity of earthquakes but we are now seeing ongoing seismic activity. Could it simply be magma reorganizing itself in the crust and filling space left by water. A reorganising that will eventually die down and cease? Of course it’s possible and probably by far the most likely outcome.
Island Movement
Ios
In the 18th of Feb update I said Ios northerly movement could be slowing. It looks like that was a bit premature, movement rate north looks constant. However the westerly movement and uplift still look to be slowing. West and North are not normal movements for Ios.
Santorini
Everything I said on the 18th still stands, slowing east and north movement. The earthquake-less downward acceleration is still happening. Santorini north movement not normal.
Amorgos
Looks to be stable speed south, possible accelerating westward movement and steady rate of uplift. Westward motion not normal for Amorgos and neither is the rate of rise.
Expert Santorini Earthquake Commentary
Geology Hub
In GeologyHub’s latest video he has mentioned that there is a theory that the theoretical magma dyke heading from Santorini to Anydros is putting magma into contact with water. This could be forcing water into existing gaps, opening them up, weakening them and causing more earthquakes.
My Opinion
From my point of view, if this is happening, when that magma is coming into contact water I think it is reasonable to expect we are getting massive increase in pressure and pressure releases, as steam builds up in the crust and then releases. Could steam explosions cause such big quakes eg 4 Richter+? I don’t know but I think it seems reasonable that they would cause some seismic activity that could be measured by seismographs even if the activity does not get classed as an earthquake. For example in yesterday’s update we saw that Anydros island seismograph is showing rougher lines versus the 19th of Feb and yet the numbers of quakes being registered is less. Rougher lines but less earthquakes on the 20th. Could steam be partly to blame for the constant barrage of events be it tiny/small/medium/large?
Shawn Willsey
Shawn Willsey is a geology professor than is occasionally doing video on this Aegean earthquake situation. In his latest video he’s covered the gammet of opinions on what is driving these quakes. He said in this latest video that as far as he is concerned, he would need to start seeing a lot more signs typical of impending eruption for him to think that there is anything but a tiny chance of a volcano erupting. Fair enough.
My Opinion
But something that intrigued me during his video was his continuing assertion that magma movement is not shallow. In all fairness, I’m not sure what his definition of shallow is. A magma chamber under Anydros island has been found at 6-7km down. That isn’t what I would called deep. And given that we don’t have reliable uplift data from Anydros and given that Anydros island has been at the heart of the earthquake swarm I would urge caution until we get some hard and reliable data.
Santorini Earthquake Summary – 21.2.25
General Reservations
A reservation I have is the uptick in this very light seismic activity versus the previous day, the 19th on Anydros. Why weren’t we seeing this light activity on the 19th but now on the 20th and 21st? What changed?
Another reservation I have is the shallowness and number of earthquakes. If the activity of the past few weeks was in part due to water-magma interaction over such a long time, what sort of condition has that left in the crust in? The crust in the Aegean is already relatively thin.
The Aegean crust thickness is homogeneous and relatively thin within the whole region
http://christeltiberi.free.fr/download/2004tirel.pdf
Thirdly we are still seeing movement in the islands Ios, Amorgos and Santorini yet earthquake activity is well down. How can we have these island movements without earthquakes? Are the crust interfaces saturated ie moving very relatively freely against one another?
And lastly, the possible connection with tidal forces and the earthquakes. There could be a correlation between large tides and earthquake activity in this situation. Given the pummeling the crust could have taken over the past weeks, will the new tides coming on the 25th cause bigger effects than they may have over the past couple of weeks?
Conclusion
Regardless of the reservations I have detailed above and regardless of the possible magma-water interactions we may have been seeing over the past couple of weeks, the data is the data, and the data says activity around the Santorini earthquake swarm is dropping rapidly, that can only be an improvement over the past couple of weeks and on this basis I would say we are closer to seeing the end of this swarm than we are to the beginning. Yes the activity we are seeing even today is unusual and it needs to be monitored but considering the activity we have seen in the previous couple of weeks, things, as of today, are a huge improvement and look to be returning to normal.
