Abstract

The earthquake with a magnitude of 6.9 occurred in the north of Samos Island on October 30, 2020, caused great damage in Izmir. The main shock quickly destroyed 17 buildings in Bayraklı and caused the death of 117 people. Bayraklı district, where the earthquake caused the most damage, is 70 km far from the earthquake epicenter, reminds the possible effects of an earthquake that will occur in an active fault passing through Izmir city center. The most important fault with a length of 40 km is the Izmir fault (IF). Studies have shown that it is not possible to provide information in situ about the Izmir fault (IF) and its surroundings passing trough the very urbanized city center. So, information on the fault and its seismicity is limited. It is greatly important to carry out field studies with alternative methods. Soil gas measurements make it possible to work on a small piece of land with a 1 cm diameter and 1 m long probe, by eliminating the obstacles on the field studies. Therefore, soil gas measurements can provide information about natural processes through gases released from the earth's crust in metropolises with excessive urbanization. Since fault lines/zones have relatively high permeability values, terrestrially produced gases such as CO₂, He, H₂, ²²²Rn, CH₄, N₂ can be easily extracted to the atmosphere. While the migration of gases is evident in fault fractures, it is highly affected by earth crust movements (compression/ dilation). For this reason, these gases in soil gas can be used to get information such as detecting buried and unidentified faults and predicting earthquakes. Among these tracers, radon which stands out as an inert gas and a member of the uranium decay series is continiously produced in earth crust and moved to atmosphere. The concentrations of radon in the soil gas are affected by physical changes such as earth crust movements. Radon migrates to very long distances with carrier gases as CO₂. Therefore, Radon (²²²Rn) and CO₂ are used together to understand geodynamic processes such as faulting and seismicity. In the proposed project, soil gas measurements will be focused on the differences in terms of seismicity between the two segments of the Izmir fault. The selected method is known, reliable, and used commonly. However, this method will be used for achieving to different objectives.

The project will be carried out by a multidisciplinary research team consisting of researchers and consultants with significant knowledge and practical experience in their fields (Nuclear Sciences, Physics, Chemistry, Geology, and Agriculture). This project is proposed by a young and dynamic team and its purpose is stated clearly and targets are determined in line with its purpose. In this direction, the duties and responsibilities of expert researchers and foreign experts in the project were clearly defined, predictions were made regarding the problems that may occur in the project, and plan B was created.