2020 Aegean Sea earthquake

The 2020 Samos–İzmir earthquake had a moment magnitude of 7.0 which struck on Friday, 30 October 2020, about northeast of the Greek island of Samos. Many buildings were severely damaged or collapsed as a result of the earthquake, with the Church the Assumption of Mary in Karlovasi, Greece, partially collapsing, while in the Turkish city İzmir, which was heavily affected by the earthquake, dozens of buildings were either damaged or completely collapsed. Emergency services in both countries immediately attended the scene, as rescue efforts continued into the night. 
117 people are known to have died in Turkey's İzmir Province, with 1,034 more injured. In Greece, there were an additional two fatalities and nineteen minor injuries. The earthquake is the most powerful in the Aegean Sea since 1981, and the deadliest in İzmir Province since a magnitude 6.6 killed four people in 1955. The earthquake is also the deadliest in the year of 2020.
Tectonic setting.
The Aegean Sea is a seismically active region with complex plate tectonics interaction both within and surrounding the Aegean Sea Plate. The region has several major plate boundary including the North Anatolian Fault which runs through northern Turkey, where the Anatolian Plate slides past the Eurasian Plate along this right-lateral strike-slip fault. Another major boundary is the East Anatolian Fault where the Arabian Plate interacts with the Anatolian Plate. This transform fault was responsible for the 2020 Elazığ earthquake.
At its southern edges, the African Plate converges north at 5–10 mm/yr towards the Aegean Sea Plate at a rate of 5–10 mm/yr. It subducts or dives beneath the Aegean, occasionally producing great Megathrust earthquakes and tsunamis including the 365 Crete earthquake. However, the subduction rate along the Hellenic subduction zone at 35 mm/yr which greatly exceeds the velocity of the African Plate. For that, north-south extension within the Aegean Sea Plate in the back-arc compensate the subduction rate. Shallow crustal earthquakes in the Aegean Sea Plate is a result of this extension, accommodated by east-west trending normal faults.
Earthquake.
Following the earthquake, Samos was affected by hundreds of aftershocks. The magnitude of the earthquake was frequently misreported as 6.6 in the Turkish media, due to an erroneous announcement by AFAD. The quake was reportedly felt in the Greek island of Crete, the BBC added. While minor shaking was also felt in some regions of Athens.
Historical seismicity.
The Samos Island and İzmir region has been rocked by major earthquakes throughout the past centuries. On the island of Samos, these earthquakes usually have minimal effects. The nearby city Izmir however have suffered serious catastrophe as a result of earthquakes.
The most destructive event in the region was the 1688 Smyrna earthquake which had an epicenter near İzmir. Extimated magnitude 7.0, the earthquake killed some 15,000 to 20,000 people in the city.
Other major events took place in 1739 and 1788, causing major damage in the city.
On 11 August 1904, Samos was rocked by a magnitude 6.8 earthquake causing substantial damage to Greece and Turkey, killing four. That earthquake according to researchers, was caused by an onshore fault (Pythagorion Fault) on the island.
Characteristic.
The earthquake occurred as a result of pure normal faulting at a shallow crustal depth within the Eurasian Plate in the eastern Aegean Sea, about 250 km north of the closest main plate boundary, where the African Plate moves to the north at a rate of approximately 10 mm per year with respect to the Eurasian. Therefore, this earthquake is considered an intraplate earthquake due to its location. 
The North Samos Fault, also known as the Kaystrios Fault is an east–west striking, north–northeast dipping normal fault located offshore, north of the coast of Samos. Running for a length of 40 to 37 kilometers, it ruptured entirely during the earthquake. The earthquake released a seismic moment of 3.3 × 10^19 Nm, which corresponded to its moment magnitude at 7.0. Maximum slip along the fault is estimated at 2 to 3.5 meters. A 2009 study determined that the fault had the potential to produce an earthquake of magnitude 6.8.
Ground motion.
The earthquake achieved a maximum peak ground acceleration of 0.27 g in Samos. Weaker ground acceleration was recorded at 0.1 g in İzmir, however, in the Bayraklı and Karşıyaka metropolitan districts, these ground motions were amplified with longer periods.
Aftershocks.
As of 8 November, over 2,800 aftershocks have been recorded. The mainshock may have been preceded by a foreshock on 5 May the same year.
Tsunami.
Tsunami information was issued by the Kandilli Observatory Earthquake Monitoring and Tsunami Warning Center to the Earthquake Research Department of Turkey 11 minutes after the earthquake but was not broadcast to the coastal regions. The tsunami arrived between 10 and 15 minutes after the mainshock.
Multiple social media posts showed water rushing through streets and ports in the region following the earthquake, along with tsunami warnings being issued for the islands of Ikaria, Kos, Chios and Samos. Flooding from the coasts reached heights of 1.9 meters (6 feet), however at Akarca, the tsunami reached heights of 6 metres (19 feet). In Azmak, the tsunami penetrated 1.3 kilometres (0.8 miles) inland, 0.82 kilometres (0.5 miles) in Akarca, and 0.32 kilometres (0.2 miles) in Sigacik. Recorded heights of the tsunami from this event were larger that of other similar magnitude quakes in the same region with the exception of the 1956 Amorgos earthquake.
Turkish coast.
In Alaçatı on the Çeşme Peninsula, the tsunami flowed up a stream and inundated inland by as much as 2.49 km. It took a fishing vessel 1.16 km inland along the stream during the inundation. Analysis of video footage on the coast showed that the tsunami had a maximum heoght of 1.7 meters when it struck.
East of Alaçatı is Zeytineli, where the tsunami severely damaged unoccupied resort houses along a stretch of beach. Debris from the damaged structures were strewned along the beach. Concrete blocks were also displaced by as much as 25 meters. A maximum inundation of 760 meters was measured, as well as a flow height of 1.9 meters at a palm tree, some 50 meters from the shore.
In Akarca, which is north of Samos, the tsunami wave heights were up to 3.8 meters, reaching as far as 290 meters inland. The maximum wave height in this area was 6 meters. A 2.2-meter surge flooded and damaged a diving center near the coast. Garden walls and fences of homes at the shore were also damaged. Cars and boats were among the large objects picked up by the surge and moved inland. The only known fatality from the tsunami was reported in this town.
Greek coast.
Multiple social media posts showed water rushing through streets and ports in the region following the earthquake, along with tsunami warnings being issued for the islands of Ikaria, Kos, Chios and Samos. On the island of Samos, the tsunami caused major flooding on its northern coast, and was recorded my multiple people on video camera. No deaths were reported by the tsunami, but two teenagers died after a wall fell on them during the quake. Many offices and businesses were immediately flooded when the surge broke through windows and doors. Waves of 1.5 to 2.0 meters traveled as far as 101 meters inland. Damage to boats and cars were widely reported after the tsunami struck.
Damage.
Initially, Turkish Minister of the Interior Süleyman Soylu stated that at least six buildings were destroyed in İzmir, but the city's mayor Tunç Soyer later put the number of collapsed buildings closer to 20.
Greek authorities from Samos stated that although buildings were damaged across the island, the worst sustained was in Karlovasi, where a large church had partially collapsed. In Karlovasi, over 100 buildings were damaged upon inspection. It is the first time since the 2017 Aegean Sea earthquake that there are earthquake-related deaths in Greece.
Many buildings collapsed in İzmir's Bayraklı and Bornova district. Most of the buildings which collapsed were built in the 1990s, based on outdated earthquake regulations from 1975. Poor construction practices and code compliance were reasons for the collapse. Additionally, the first floors of these buildings were altered for commercial use such as shops. Taller buildings with heights of 100 to 240 meters, however, did not sustain structural damages. The city is also built on soft sediments in a basin which amplified the intensity of shaking despite its distance from the epicenter.
On 4 November, mayor of İzmir Tunç Soyer stated that 15,000 people lost their homes only in İzmir in the earthquake.
Total damage is estimated to be in the millions for Greece, and over $400 million for Turkey.
Casualties.
117 people died and 1,034 more were injured in Turkey, all but one from the city of Izmir, while two teenagers died in Greece after being crushed by a wall on the island of Samos; 19 others were injured in Greece. The other Turkish victim outside Izmir died from drowning in the advancing tsunami in the district of Seferihisar.
Relief operations.
Right after the earthquake, Turkish Minister of Health Fahrettin Koca stated that about 40 ambulances, 35 emergency rescue teams and two ambulance helicopters had reached the scene, while Turkey's Ministry of National Defence stated that one of its planes had departed from Etimesgut Air Base to transport AFAD and gendarmerie teams to the region. The Turkish Red Crescent immediately deployed teams from six cities to provide food to those affected by the earthquake. More than 1,200 workers were involved in rescue efforts involving at least 13 buildings in İzmir, which continued into the night. According to Al Jazeera, the personnel involved in the rescue operations had reached about 8,000, including 25 rescue dogs. Turkish authorities stated that 106 people were rescued, while the local government had set up tents to house about 2,000 people overnight. A three-year-old Ayda Gezgin was also said to have been the second little girl rescued on Tuesday, from an 8-story building. A total of 17 collapsed buildings were part of the search and rescue operations, according Mehmet Gulluoglu, head of Turkey's Disaster and Emergency Management Presidency.
International reactions.
Countries:
International organisations: