Abstract

It is vital to calculate the magnitude of an earthquake to give a response and disseminate the early warning to evacuate the people as soon as possible. Generally, the magnitude determination process takes a couple of minutes and has some difficulties because the propagation effect depends on the epicentral distances. The moment magnitude is calculated for large earthquakes, in general, using body waves that it takes at least ten minutes to calculate. This time is too much for giving an alarm and evacuating the people who live near the coastal areas. This study is concentrated improve and implementing the P-wave moment magnitude calculations to use in early warning issues by using a sample case that occurred on October 30, 2020, on Samos Island that is near to Aegean coast of Turkey. It was destructive effects on İzmir. In total, 115 people have lost their lives and more than a thousand people are wounded. The magnitude of this event was announced as 6.6 (Mw) by the Disaster and Emergency Presidency (AFAD), Earthquake Institute. A small-scale tsunami wave arrived in the Sığacık-Seferihisar region. The P-wave moment magnitude is calculated as 7.0 in this study, and it is similar to the Global Centroid Moment Tensor Solution (Mw-GCMT) result. This study shows the technique can be used for early warning purposes at regional distances.

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