Santorini Earthquake Update 20.2.25 – Tide Connection
We are seeing a continued drop in energy released from earthquakes although the number of earthquakes being measured is still well above the norm. In today’s Santorini earthquake update we’ll briefly look at seismic activity changes, seismographs and the location of recent epicentres before jumping into something a bit different, we’ll look at the pattern of earthquake activity and see if there is any relation to the tides ie are the highest/lowest tide periods coinciding with jumps in earthquake activity.
Click here for links to live earthquake data around Santorini
Seismic Data
Cumulative Earthquake Energy Released
Using the data at volcanodiscovery.com we can see that the total energy being released from earthquakes is continuing to fall rapidly. As of 11:20GMT today cumulative energy release is around 20MWh, this compares to around 90MWh yesterday. However the number of earthquakes being recorded is still over 700% higher than normal.
Seismic Location
In the previous couple of days we have seen the epicentre of the swarms moving around a lot between days. Today the epicentres are similar to yesterday however there could be a very slight trend moving slightly closer to Santorini and Ios. But these quakes are relatively weak and are probably not felt on either island and the vast majority of these quakes are happening between 2 and 10km depth. Note, on the 15th of Feb the quake epicentres were around the same area as today so what we are seeing at the moment is not something new.
Seismographs – Anydros
Looking at the seismographs from Anydros island I think we can say there is more light activity (the lines are rougher) on the 20th versus the 19th but the number of larger events is definitely less. The number of events today (using volcanodiscovery data above) is less than yesterday so I have to assume the line roughness on the Anydros is not being registered as earthquakes. Whether this is a normal picture for Anydros I do not know because the archive data only goes back to February this year after the swarm had already started.
To put the graphs above into some perspective. Here is a graph from the 5th of February. We are in a completely different place today.
Noticeable and constant activity. Things have improved hugely from the 5th of Feb
Tide Effect – Is There A Pattern?
Are the tides playing a part in the Santorini earthquake swarm. Is the pull of the moon and the sun affecting seismic/magmatic activity and if so, can we make any type of prediction?
Below I have made a “graphic” overlaying tide time and height versus the number of earthquake and their cumulative energy release. If my mind is not playing tricks on me I see a definite correlation. Feel free to comment if you think I am misreading the graphs.
Basics
Let’s establish some baseline information.
Tides
I believe it is said that the moon and the sun have minimal power when it comes to affecting earthquake activity. On the flip side, I would say the moon and the sun have the power to move billions if not trillions of tons of water (tides).
Normal Circumstances
Normally the earthquake activity in the Aegean is very stable over time. In other words, in normal circumstances, the tides (the moon and the sun and water movement) play a minimal part in earthquake activity. However something has changed for the earthquake swarm to start, so I would say at the moment, the circumstances are not normal and perhaps the current circumstances have created a situation where the movement of the sun and the moon play a much bigger part in earthquake activity than is normal.
The Graphic
Starting from the left, the first of February.
1st to 6th of Feb – A Lag
I think it’s fair to say that the earthquake activity started around the time the tides were already at their extremes (highest and lowest tides). There was a lag between earthquake activity increasing and the tides increasing. Also, the tides had started to drop around the first but the quake activity was still increasing. A lag of around three days.
6th to 9th of Feb – Dropping Together
From the 6th to the 9th the tides were at their lowest and most stable (difference between high and low tides). And we see earthquake activity, the number of quakes, dropping throughout this period.
9th to 13th of Feb
From the 9th to the 13th the tides grew in size and we see a big uptick in earthquake activity as the tides started to increase. The tides peaked around the 14th of Feb but the earthquake activity had peaked two days earlier. From the first to the sixth of Feb the quakes were lagging the tides by around three days. On the 14th the tides were lagging the quake activity by around two days.
13th Feb to 15th Feb
Peak tides during this time and earthquakes activity was also at it’s peak although generally dropping through this time frame.
15th to 21st of Feb
Tides were dropping throughout this time and earthquake activity was also generally been dropping.
Today to 25th of Feb
At the moment tides are at their lowest (the smallest difference between high and low tide) and at the same time we are seeing almost the lowest number of quakes since the swarm started. And the intensity of the quakes is much lower now.
The Test
I guess the test to see if there is a lasting quake-tide connection will come on the 25th when the tides start to increase again. On the 9th/10th quake activity picked up almost immediately when the tides started to increase. Will we see the same again?
Tide-Earthquake Connection – Conclusion
I think it’s fair to say there is some connection between tides and earthquakes at the moment. That connection may continue, it may not. Around the 25th of Feb we should start getting an idea if the correlation is continuing. If by the 28th earthquake activity is continuing to drop back down to normal levels we might be able to say the connection has been broken.
Santorini Earthquake Update 20.2.25 – Summary
Earthquakes are continuing to drop in frequency and intensity. There is a possible connection between tides and the number of earthquakes. From the 25th onwards we might be able to see if that connection is still there. Stay tuned.
