ESenTRy: an on-site earthquake early warning system based on the instrumental modified Mercalli intensity

Abstract

AbstractEarthquake early warning systems (EEWSs) are real-time seismology-based applications that purpose to reduce earthquake damage by taking some precautions for environments that are likely to be damaged. These systems are divided into two categories as on-site and regional. In this study, an on-site EEWS called ESenTRy, consisting of an accelerometer, GPS and communication components, has been designed. In this scope, a Windows operating system-based software has been developed using the .NET Framework and C# language. The developed software has the ability to read the Güralp Compressed Format strong motion data in real-time, compute the strong motion indices such as destructive intensity, real-time intensity and instrumental modified Mercalli intensity, issue an alarm in the target area and alert the defined Modbus clients. To test the reliability of ESenTRy, two simulations have been performed using the strong motion data belonging to the magnitude 7.7 Kahramanmaraş-Pazarcık earthquake that occurred in Türkiye on February 6, 2023, at 01:17:32 UTC and magnitude 5.9 Düzce-Gölyaka earthquake that occurred in Türkiye on December 23, 2022, at 01:08:15 UTC. In the test applications, depending on the distance between the stations and earthquake epicenters, the time difference between the Level-2 alarm trigger times and S-wave arrival times varied between 1.5 and 16 s, while the time difference between the Level-2 alarm trigger times and P wave arrival times varied between 0.5 and 29.5 s. The flowchart diagrams of the developed algorithm and results obtained from the simulations are presented in detail.