Earthquake in Lesvos: Why experts are worried

An alarm has been raised at Lesvos after the barrage of seismic tremors that occurred on the island. The entire state apparatus has been put on high alert, while local authorities have implemented the “Englades” Plan.

Speaking on MEGA’s main news bulletin, professor of geology and natural disaster management, Efthymios Lekkas, said that it is not certain that the largest earthquake which happened is the master. “We can’t say for sure that this was the main earthquake, of course there are a lot of possibilities for that, and we can’t say for sure because firstly the seismic activity is evolving and secondly, unfortunately, there is a heavy seismic past in the area” , he said. “We are on alert, we are observing the evolution of the phenomenon”, noted Mr. Lekkas, stressing that the Authorities are on their feet and, in the event of a larger earthquake, are ready to intervene.

“The Anti-Seismic Planning and Protection Organization in collaboration with the Ministry of Civil Protection, we have activated all the procedures provided for by ‘Xenokratis 2’ and we are ready, in the least case that we have a bigger earthquake, to intervene.”

Regarding the fault that caused the double earthquake in Lesvos, he said: “Based on historical data, it can produce an earthquake of about 6.5 on the Richter scale when fully activated. Now we have the activation of a conjugate fault of the great fault zone of Agia Paraskevi. We have a smaller size and I think it will stay that way, although the seismic activity is ongoing, which makes us very cautious.”

“There is a possibility that other faults will ‘wake up'”

According to Mr. Lekka, the double earthquake in Lesvos can “wake up” other faults in the wider region. “There’s a small chance for that too, but we’ve also been dealing with too many aftershocks so far. The possibilities are open. Of course, I repeat that the chances of having a bigger earthquake, I emphasize, are extremely small.”

As he said, the consecutive earthquakes that have occurred in the last period, “do not worry us, given that the seismic excitations observed in different parts of the country are completely independent, belong to a completely different seismotectonic framework, they do not affect each other, simply and they only coincide in time”.

Therefore, he said, there is no general agitation in the Greek area, we simply have individual agitations. “It’s just a coincidence of time. We have no data to support the opinion that we have a more general agitation in the Greek area”, he stressed, underlining that the issue of landslides caused by the earthquake should be addressed immediately.

“What is particularly important is that we should look at the issues of landslides. Special attention should be paid there so that we don’t have accidents along the road network,” he said.

In the central news bulletin of ANT1, he spoke Research Director of the Geodynamic Institute, Gerasimos Papadopouloss. As Mr. Papadopoulos said, “the region has a history of significant earthquakes, but we must see the characteristics of the current activity. Characteristic first, the seismic activity takes place on the land part of the island, not in the sea. This makes the situation more dangerous, because the epicenters of the earthquakes are very close to populated areas in towns and villages in the region.”

“It’s still too early to say if it was the main earthquake, we don’t have enough data. Perhaps tomorrow we will be able to have a more informed view as we expect more smaller earthquakes to occur. These earthquakes contain valuable seismological information to be able to arrive at this crucial question”, he stressed,

“Another feature is the history of the area. Consequently, when one evaluates all of this, then one understands that there should be the activation of the preventive part of the “Englades” operational plan”, he added.

Referring to the residents, he said that “they should be patient and calm, and if some have even minor damage to their home or workplace, they should seek the opinion of a civil engineer or the municipality”.

Regarding the possibility of a stronger earthquake, he said that “theoretically, these possibilities always exist, however, here this possibility has a very small probability, but the State, central and local, should proceed with all possibilities, even with the extreme one. As the seismic sequence is currently developing, we cannot say whether it was the main earthquake or what is the size ceiling it can reach. We are in a state of uncertainty which will become clear in the coming days.”

Finally, as to whether he is worried about a fault in general, he said that “attention needs to be paid to the three seismic foci that have simultaneously been activated in Evia and are still active, while as he said there is also the foci in the Cretan Sea north of Neapoli and Agios Nikolaos which is very active from December 28 onwards. However, there we have a safe distance from the intervening maritime space”.

Earthquake in Lesbos: The damage

The earthquake damaged more than 30 houses on the island, from Mandamado to Pelopi, Lepetymnos and Stipsis. Plaster has also fallen in the kindergarten of Lepetymnos, damage has been found in the church of Agia Triada in the village of Stypsi and in the chapel of Agia Paraskevi in ​​Molyvos, while rocks have fallen on the provincial and rural network in the highlands of the island. According to the president of the Pelopi community, there are some demolished warehouses and stables on estates.

According to the Mayor of Western Lesvos, Taxiarchis Verros, “the services of the Municipality are ready and communication has been made with the relevant Ministry and with Professor Efthymios Lekkas. The Seismic Risk Assessment Committee will meet in the next few hours for further information.”

The dispute over the fault of Agia Paraskevi

Disagreement seems to exist between seismologists and professors as to whether the earthquakes that occurred on Saturday in Lesvos originate from the great fault of Agia Paraskevi. From this fault came the most destructive earthquake on the island, which occurred on March 7, 1867, centered on the village of Napi. It measured 6.8 on the Richter scale and was followed by 25 aftershocks. From the earthquake, 550 people lost their lives, 816 were injured and 10,275 buildings were damaged.

Celentis Warning – ‘Needs some care’

“A little attention is needed because the fault that caused today’s earthquakes is close to the big fault of Agia Paraskevi that runs through the island from one end to the other,” seismology professor and Director of the Geodynamic Institute Akis Tselentis told APE-MPE. “We’re not 100% sure it’s the gentleman earthquake and for the moment it is difficult to say something like that” he added.

“They did not come from the fault of Agia Paraskevi that caused a devastating earthquake in 1867” say professors of the University of the Aegean and AUTH

Professor of Physical Geography of the University of the Aegean, Dr. Nikos Zouros, who early recorded the outdoor evidence of seismic activity, as well as the professor of Neotectonics and Paleoseismology at the Department of Geology of AUTH, Spyros Pavlidis.

“Until this time the post-seismic activity, after the strong second earthquake at 8.40 in the morning and the one that preceded it in the early morning which was very strong and with noise, is progressing smoothly,” Mr. Zouros told GRTimes.

He added that “from the data we have collected so far and also from the knowledge we have about the region, the epicenters of the earthquakes are distributed in a parallel fault, which is located further west than that of Agia Paraskevi, is smaller and therefore its potential it cannot produce a much larger earthquake. If we were on the fault line of Agia Paraskevi because of its history there would clearly be more concern. Be that as it may, and according to all the data we collected from the countryside, the earthquakes did not come from the fault of Agia Paraskevi, but from the smaller parallel fault that crosses in the same way Lepetymnos, the largest mountain of Lesvos”.

Also regarding whether the magnitude 4.9 earthquake was the main earthquake, the professor of the University of the Aegean noted that if “and this is something we cannot say with certainty yet as not even 24 hours have passed, due to the development but also of the fault that originated we can say that it was the main earthquake. But for greater certainty, a sufficient period of time should pass to see the post-earthquake sequence as well.”

On the same wavelength, the study of the phenomenon by the professor of Neotectonics and Paleoseismology at the Department of Geology of the AUTH, Spyros Pavlidis, who speaking to GRTimes, underlined that “it was an area that we have studied a lot in collaboration with the professor of the University of the Aegean , dr. Niko Zouro. We know the faults in the area well, but we will definitely be able to say more after we have a larger sample of aftershocks.”

“However, from the first studies we have already done, it seems that it is not the big fault of Agia Paraskevi which caused a devastating earthquake in the area in 1867. It was a very big and destructive earthquake, but it is not connected to the fault that caused the two morning earthquakes on the island” he added.