Filenews 28 April 2022 - by Vassos Vassiliou
We built two airports, one on an active seismic fault and the other near a fault. On a fault, Larnaka airport was built and near a fault is Paphos Airport, as evidenced by the last earthquake with a magnitude of 4.7 on the Richter scale that occurred on Tuesday night.
As stated by the Deputy Director of the Geological Survey Department, Christodoulos Hadjigeorgiou, the epicenter of the main earthquake was identified ten kilometres southeast of Paphos in the wider area of Pafos – Mandria airport.
Commenting on the seismic activity in the area of Cyprus, Mr. Hadjigeorgiou referred to the subduction of the energy plate under Cyprus, which, as he said, is capable of giving the seismic activity observed, either directly from the precipitation itself, or within the land area.
A seismologist with whom "F" spoke, calculated that the epicentre of the second earthquake (3.9 Richter) was the community of Natas in Paphos. As for the earthquake of 4.7 degrees on the Richter scale, he believes that it seems to have been caused by the activity of the "Cyprus Arc", which in turn activated the fault of the river Xeros that affects the area where the dam of Asprokremmos is located.
The earthquake the day before yesterday is estimated to be located in the same seismic area that caused the great earthquake of 1953 and the earthquake of 1996. It is recalled that on September 10, 1953, a devastating double earthquake occurred in the Pafos district of magnitudes 6 and 6.1 on the Richter scale. According to the Geological Survey Department, 40 people were killed, 100 injured and 4,000 were left homeless. 158 villages and towns were affected. Most of the damage was caused by landslides and superficial cracks. Within seconds, 1,600 houses were destroyed while another 10,000 houses and public buildings were damaged.
Moreover, on 9 October 1996 there was a very strong earthquake with a magnitude of 6.5 on the Richter scale. Two people died of secondary causes and 20 were slightly injured. Limited damages were caused, mainly in Paphos and Limassol.
It is worth noting that in Paphos there is also a transformation fault, about 70 million years old, which passes through Polis Chrysochous, Giolou, Drymou, Agios Dimitrianos, Polemi, Galataria and Agios Ioannis.
The seismologist contacted by "F" said that in recent months earthquakes have occurred along the Cyprus Arc and a reclassification of forces followed, in which the rocks take a new position. In this process the rocks move inside the earth and as a result they crumble, which causes energy release which causes earthquakes to the surface of the earth.
The same seismologist observed that based on the statistics of the Geological Survey Department, earthquakes between 5.1-5.5 degrees on the Richter scale occur every 26 years or so. Since the previous major earthquake in the region occurred in 1996, 26 years have passed, he said, adding that the statistics are indicative, in the sense that they may show a discrepancy. It is recalled that the initial estimate of the earthquake the day before yesterday, showed its magnitude of 5.1 Richter.
Active and inactive faults of Cyprus
The faults that exist in Cyprus and which caused earthquakes are either considered inactive or are active:
► The Gerasa fault in Limassol which, according to the Geological Survey Department, in 1999 had caused the strong earthquake of 5.6 on the Richter scale. The Gerasa fault is considered the largest in Cyprus and has a length of 25 km. The fault breaks down into two sections 10 and 15 km long respectively. It was considered the only active fault in Cyprus.
According to estimates, it cannot cause an earthquake beyond 5.6 on the Richter scale, although an earthquake of this magnitude will shake the whole of Cyprus. (A fault is considered active when an earthquake was created in it in the last 10,000 years).
► The fault of Ovgos in Nicosia.
► The fault of Kythrea.
► The fault of the Xeros River in Paphos as well as another fault also in Paphos.
The largest fault was considered to be the Arakapas fault which, however, is inactive. It is also called a transformation fault, because it was created 80 million years ago, when Cyprus was still under the sea and in the process became inactive.
About 60-70 million years ago, when Pentadaktylos and Troodos began to emerge from the sea, gradually began the erosion of materials that constituted the two mountains, resulting in these materials to fill the basin of Mesaoria.
According to estimates, because the corrosion was relatively fast, the materials deposited did not manage to be compressed on their own and under their weight, which resulted in them being subsided through the centuries. This process leads to the creation of cracks that contribute to the filling of the gaps created.
The materials that came from the erosion of Pentadaktylos reach up to Mia Milia while the rest of the materials whose erosion created the soil of Nicosia, comes from Troodos.
The limit of pentadaktylos' materials extends up to Kionely while the limit of the materials of Troodos reaches up to Agios Dometios.
Many materials were transported by rivers. The rivers Serrachi and Pedieos continue to bring various materials to this day.
