Filenews 12 February 2023
Cyprus has been shaking through the centuries, something that emerges from historical references and archaeological findings that testify that the island was hit in the past by strong earthquakes, which, in several cases, destroyed its cities. Historical data show that 20 destructive earthquakes occurred between 26 BC and 1900 AD.
According to the statistics of the Geological Survey Department, every approximately 153 years the area of Cyprus is affected by an earthquake with a magnitude of more than 7 Richter. Every 52 years it is hit by an earthquake greater than 6.5 Richter, every 17 years it is shaken by an earthquake of more than 6 Richter, every six years by an earthquake exceeding 5.5 Richter and every two years by an earthquake greater than 5 Richter.
Of course, the above earthquakes are not the only ones since, according to the Geological Survey Department, the seismological centre of the Department records every year, on average, at least 2,000 earthquakes, of which 1,300 have outbreaks in the wider area of Cyprus. Of these, the percentage of earthquakes felt by citizens is limited to 0.5%.
The most recent devastating earthquake occurred on September 10, 1953, killing 40 people. 100 were injured and 4,000 were left homeless. 158 villages and towns were affected. Of course, strong earthquakes followed in 1995, 1996, 1999, which confirms in practice that Cyprus is in a seismic zone.
According to the Geological Survey, Cyprus is located in the seismic zone of the Alps-Himalayas in which 15% of earthquakes occur worldwide. The seismicity of Cyprus is mainly attributed to the "Cyprus Arc" which forms the tectonic boundary between the African and Eurasian lithospheric plates in the Eastern Mediterranean region. The African plate moves north towards the Eurasian plate, resulting in the collision of the two plates and the diving of the African plate under the Anatolian microplate (part of the Eurasian plate where Cyprus is located).
According to the Geological Survey Department, the Cyprus arc is mainly divided into three sections with its western part being located west of the Akamas peninsula and showing the most intense activity with earthquakes of intermediate depth (up to 130km) since probably, near the Gulf of Antalya appears the subduction zone of the oceanic crust of Tythys under the continental plate of Eurasia. The central part occurs south of Cyprus and also exhibits intense seismicity, mainly with surface earthquakes. Finally, the eastern part of the arc referred to (in the literature) as "The Latakia Fault" has low seismicity with no earthquakes of intermediate depth, possibly due to non-active precipitation.
The most intense seismicity of Cyprus is observed in the central-western part of the Cyprus Arc and on land faults in Paphos, Limassol and Larnaca.
Based on the above data, the basic defence of man is to construct buildings and infrastructure that withstand the phenomenon of the earthquake or at least do not collapse easily, resulting in a large number of victims as happened with previous earthquakes, mainly in other countries. One could say that after 1994, when the Cypriot anti-seismic regulation came into force, the buildings are constructed to better standards and are generally more durable, provided that the relevant terms and conditions are complied with, that there is supervision, that appropriate materials are used, etc. Theoretically, since 2012, when the Eurocodes relating to earthquakes were implemented, buildings have been constructed even more resistant to earthquakes.
But it's not just the buildings built after 1996. There are tens of thousands of buildings which were previously constructed and which were already damaged by the great earthquakes that preceded them. They endured, but it is believed that they were left with the imprint of the earthquakes, even if the damage caused was not great. It is worth noting that after the great earthquake of 1996, about 10,000 buildings were inspected that showed minor or large damage, although most of them were small. If the fall of balconies (mainly in Limassol and Paphos) is added to the equation even without an earthquake then the bell has long since rung. Not to mention the fact that after the Turkish invasion, when pentadaktylos and its quarries were occupied, the materials used in the free areas were not the best. Of course, the fact that many buildings (from houses to hotels) began to be constructed without permits with dubious supervision must also be taken into account.
All this creates the need to inspect the buildings, in order to see "where they stand" from a static point of view. The ETSC has raised the issue and is bringing it back to the point of misunderstanding. The issue of the periodic inspection of buildings has already been raised by MP Marinos Mousiouttas before the Parliamentary Committee on the Interior and the discussion has progressed considerably. Of course, to be fair, there is also the issue of the cost of control and the fact that not everyone can pay, let alone the cost of repairing buildings, which will be judged by what inspections are statically flawed.
However, taking into account the total cost of the State and taxpayers from extensive disasters in the event of a catastrophic earthquake, then the right balance should be found, even by subsidizing the controls of buildings of vulnerable groups. It is also considered necessary to control public buildings such as cinemas, churches, stadiums, large department stores, banquet halls, schools, hotels and generally places where a large number of people or employees gather.
Eternal rifts
In Cyprus there are active faults that continue to cause earthquakes.
In the area of Akrotiri it is estimated that there are many small faults which, however, are considered not to be able to cause earthquakes of large magnitude. A large earthquake can cause the faults of Gerasa which is relatively close to the faults of Akrotiri. On August 11, 1999, the Gerasa fault caused an earthquake with a magnitude of 5.6 on the Richter scale. The strong earthquake (centred on the village of Gerasa) was strongly felt throughout the island. It caused damage to buildings in Limassol and villages in the northern part of the province. A total of 40 people were slightly injured due to panic. A large number of aftershocks continued for many months. The 25 km long Gerasa fault is the only active fault in Cyprus. The Gerasa fault splits into two sections 10 and 15 km long respectively.
Faults also exist in other areas of Cyprus, such as the Ovgos fault in Nicosia, the Kythraia fault and two other faults in Paphos. The Ovgos fault passes under Nicosia and is associated with earthquakes of up to 4.5 magnitude on the Richter scale.
According to the Geological, in Cyprus the largest fault was the Arakapas fault which, however, is inactive. The Arakapas fault, also called the transformation fault, was created 80 million years ago, when Cyprus was still under the sea and in the process became inactive.
According to estimates, about 60cm-70cm ago. years, when Pentadaktylos and Troodos began to appear above sea level, gradually began the erosion of materials that made up the two mountains, as a result of which these materials filled the basin of Mesaoria.
We missed the tsunami
As earthquakes occur thousands of miles away, we feel the danger but the distance works reassuringly. Some phenomena, such as the tsunami, seem very distant to us but are not unknown for Cyprus.
According to historians, tsunamis have been observed in Cyprus and the surrounding areas, caused by underwater earthquakes, although indeed for Cyprus the tsunami is a rare phenomenon.
Such a wave could cause damage to low-lying areas (such as coastal towns) penetrating to a depth of up to 500 metres from the coast.
The last tsunami to shock humanity occurred on December 26, 2004, following an earthquake of magnitude 8.9 that struck Sumatra killing 160,000 people in five countries.
Especially in the case of Cyprus, as it emerges from an article by the Senior Geological Officer and head of the seismological Sylvana Pilides, in the event of a tsunami, Paphos will be the first to receive the blow perhaps in just 20 seconds from its occurrence. It will be followed by Limassol in 4 minutes, Famagusta in 25 minutes and the rest of the coast of Cyprus within one hour.
The above is based on a simulation of researchers (2007) regarding the tsunami, although the exact time depends on the distance that an earthquake occurs, its magnitude, the focal depth as well as other factors.
Historically, the most "recent" earthquakes are the following:
• February 23, 1906: Strong earthquake of 5.3 Richter. It was felt all over the island and caused significant damage in Limassol-Kolossi.
• September 29, 1918: Earthquake 6.3. It was felt all over the island and especially in Larnaca and Famagusta as well as in Israel and Lebanon.
• February 18, 1924: Earthquake 6 Richter that was felt mainly in the south-eastern part of the island causing minor damage in Famagusta.
• 13 December 1927: 5 Richter earthquake in the Limassol area. It caused significant damage to buildings.
• May 9, 1930: 5.4 Richter earthquake. It was catastrophic and mainly affected the district of Pafos (churches and houses in Paphos, Peyia, Emba).
• June 26, 1937: Earthquake of 4.7 Richter in southwestern Cyprus. It destroyed houses and churches in Pachna, Platres, Pentalia, Omodos, Arsos, Salamiou and caused landslides in Arminou.
• January 20, 1941: 5.9 magnitude earthquake in the Eastern Mediterranean. It caused significant damage in the Famagusta district (injuries and collapses of houses in Paralimni and Famagusta), damage in Nicosia and Larnaca and created a small tsunami that hit the coast of Israel.
• December 9, 1947: Earthquake 5.4. It was felt throughout the island, Turkey and in Northern Israel.
• September 10, 1953: 6 Richter earthquake. Catastrophic double earthquake in the district of Paphos. 40 people were killed, 100 injured and 4,000 were left homeless. 158 villages and towns were affected.
• September 10, 1953: 6.1 Richter earthquake.
• September 15, 1961: 5.7 Richter earthquake in Larnaca
• 28 March 1984. Earthquake 4.5 Richter.
• 23 February 1995: Devastating earthquake of 6.1 in the district of Pafos with two dead. Several houses collapsed in the villages of Pano Arodes and Miliou.
• October 9, 1996: Earthquake 6.5. Two people died from secondary causes and 20 were slightly injured.
• August 11, 1999: Earthquake 5,6 Richter with epicentre in the village of Gerasa.
• April 15, 2015: 5.6 Richter earthquake centred in the sea west of Kissonerga in Paphos
