The Izmir Metropolitan Municipality, which carries out the most comprehensive earthquake research and risk reduction projects in Turkey, created a tsunami hazard analysis model on the Izmir coast with the participation of academics from the Middle East Technical University. Within the scope of the study, Izmir's 600-kilometer coastline and the districts adjacent to the coast were individually examined and mapped. In light of the information obtained, a comprehensive study will be carried out both to evacuate citizens against possible tsunami events and to take other precautions.
The earthquakes that occurred in the Aegean Sea in recent days have once again brought the risk of tsunami to the agenda in Izmir. Continuing the building inventory, seismicity-tsunami research and microzonation studies that will form the basis for the Earthquake Master Plan, Izmir Metropolitan Municipality has also completed the hazard analysis modeling against tsunami events with 10 academicians from METU under the leadership of Prof. Dr. Ahmet Cevdet Yalçıner. Accordingly, modeling was performed by calculating possible tsunami incursions for Izmir's 600-kilometer coastline and all districts adjacent to the coast. In light of all the information obtained, mapping will be done for the evacuation of citizens and signs will be prepared for escape routes. In addition, other measures will be discussed.
Database created, modeling done, map created
Earthquake Risk Management and Urban Development Department Director Eylem Ulutaş Ayatar stated that they completed the hazard analyses against possible tsunami events in the coastal areas of the Izmir Metropolitan Municipality and provided the following information regarding the studies: “First, we created a database in which the source mechanism that could create a tsunami and the facilities in the impact area were determined. Then, we carried out the tsunami modeling by taking the source into account. The progress of the tsunami waves on land, their current depths, and hazard distributions were revealed and finally, we obtained our dominant maps.”
All information on tsunami risk is available
“We can say that we are at risk of both earthquake and tsunami as Izmir, but the important thing is to define this risk and take precautions against it,” said Eylem Ulutaş Ayatar, adding that they have all the information that needs to be known about tsunami on the Izmir coast. Noting that they are carrying out their work in light of this information as the Izmir Metropolitan Municipality, Eylem Ulutaş Ayatar said, “After this stage, signs will be prepared to inform citizens and studies will be carried out to take structural or non-structural precautions.”
Izmir's shores were put under the spotlight
The conductor of the study, Middle East Technical University Civil Engineering Department Coastal and Marine Engineering Branch retired faculty member Prof. Dr. Ahmet Cevdet Yalçıner, stated that they conducted a modeling-based tsunami hazard analysis for İzmir. Noting that they worked on İzmir’s 600-kilometer coastline and calculated possible tsunami inundations for all districts adjacent to the sea, Yalçıner said, “Since we needed to create a very healthy database to do this, a detailed and high-resolution bathymetry and topographic database was prepared in cooperation with İzmir Metropolitan Municipality. Calculations of dominant areas on the coasts were made according to the tsunami-generating potential and characteristics of the faults in the sea. Possible dominant areas were mapped for each district.”
Evacuation maps will be created and signs will be prepared for escape routes.
Within the scope of the study, many issues such as structural measures to reduce the impact of the tsunami in places where it is expected to be effective, whether some structures can be placed on the coasts for this purpose, the costs and performances of these structures were examined using the maps obtained. Yalçıner, who conveyed the studies to be carried out for the citizens in the light of these studies, said, “Awareness-raising studies will be carried out on what people can do against the tsunami effect and maps will be created on how to evacuate from the regions that will be flooded when the tsunami comes to the coasts. Information boards and signs showing escape routes and safe areas will be prepared on the coasts based on the evacuation maps.”
Izmir will be an example
Yalçıner, who reminded that a similar study to the one conducted in İzmir was completed by the İstanbul Metropolitan Municipality for the districts on the Marmara coast, said, “That study was shown as an important study by UNESCO. This time, the same study was conducted on the 600-kilometer coastline of İzmir. We will carry out the next steps in cooperation with the İzmir Metropolitan Municipality. İstanbul has set an example for İzmir, and İzmir will set an example not only for our other provinces but also for cities around the world. We have come a long way in meeting UNESCO’s requirements step by step in order to be among the ‘Tsunami Ready Cities’. We will complete the remaining part.”
“Tsunami events exceeding 30 meters do not occur in the Aegean Sea”
Yalçıner, who said that the riskiest areas in Izmir regarding tsunamis are the areas close to the coast and at low elevations, and that there are no settlements in these areas, continued his words as follows: “Signs will be prepared for evacuation routes in areas such as Alsancak where many people live. It is important for citizens to be aware of these signs. Tsunami events exceeding 30 meters in the oceans, as experienced in Japan, do not occur on the Aegean coast. The Aegean Sea is shallower than oceans. An earthquake or other events greater than magnitude 7 will create a tsunami. In these events, it takes some time for the wave to reach the Izmir coast. An early warning system has been established in Turkey and the Kandilli Observatory Earthquake Research Center is run by me. The Kandilli Observatory, which works in conjunction with UNESCO against tsunami events, gives warning messages. After receiving the news, it is possible to stay away from the coast until the tsunami approaches.”
Yalçıner also said that the speed of the wave is faster than a person's running speed, so he emphasized that it is necessary to get away without waiting. Yalçıner said, "If a captain is at sea, he should go to water deeper than 50 meters. The general sign of a tsunami is the slow ebb of the sea."
“As a result of a possible volcanic eruption, the tsunami will not reach the shores of Türkiye”
Yalçıner, who also made an assessment on the earthquakes and volcanic eruption possibilities in the Aegean Sea in recent days, said, “There are earthquakes exceeding 2 thousand in the Aegean Sea. These earthquakes may be the precursors of a major earthquake. These earthquakes may not have an effect or an undersea volcano may erupt where the earthquakes occur. This may also create a tsunami. The tsunami that sets off may travel through the Aegean Sea and reach our shores. We looked at all these alternatives and modeled this situation. We concluded that the coasts of İzmir are not at risk against tsunamis that may occur in these events. In other words, the tsunami waves that will originate from there will not reach İzmir and the coasts of Turkey to the north, or if they do, they will be weak in terms of impact.”
Following the 30 magnitude earthquake that occurred on Samos Island on October 2020, 6.6, a tsunami was experienced in the Sığacık Neighborhood of Seferihisar. While one person lost his life due to the tsunami, a fishing shelter and boats attached to the marina sank, and houses and workplaces on the coastline were damaged.
A comprehensive earthquake study program is underway
Izmir Metropolitan Municipality continues its work on four fronts to make the city disaster-resistant and to create living spaces that are compatible with nature. When the building inventory, seismicity-tsunami research and microzonation studies that will form the basis for the Earthquake Master Plan are completed, the necessary data for a safe city will be obtained. All research results will be integrated and the most realistic analysis of the structure-ground interaction under earthquake effects will be made. Earthquake hazard map and settlement suitability maps will be created. Necessary precautions will be taken against the tsunami hazard that will affect the coasts.
Izmir Metropolitan Municipality, within the scope of building stock studies, Bornova and BayraklıInventory of approximately 100 thousand buildings was prepared in . With this study, the behavior of the buildings during earthquakes was determined and an identity document was created that included all kinds of information about the building. The building inventory studies will be completed in 2025. KarşıyakaIt will continue for 22 thousand 767 houses located in.
The “Izmir Seismicity Research Project”, which is being carried out in a 100-kilometer radius area taking Izmir city center as reference, is still known as the most extensive and comprehensive earthquake research project in our country. When the project is completed, concrete information will be obtained on how large an earthquake Izmir may face in the future, the potential magnitude of the earthquake acceleration that will affect the structures, whether the earthquakes carry the risk of creating surface faults, and possible tsunami scenarios that may occur on the coasts.
The ground structure of Izmir is also being examined with microzonation studies. The Bornova basin, which was most affected by the October 30 Izmir Earthquake (Bayraklı, Konak, Bornova districts) and studies on the behavioral characteristics including the soil structure and basin effect are continuing rapidly. Within the scope of Bornova microzonation study, approximately 7 drilling wells were opened in an area of 12 thousand 1500 hectares. The studies carried out in the district are about to be completed.
In the near future Karşıyaka Microzonation studies will be initiated in the district. It is aimed to complete the studies in stages in the other 11 central districts.
