EVENT DETECTIONMAGNITUDE 5.3 EARTHQUAKE 100KM OFFSHORE TURKEY ACCURATELY DETECTED USING 2 STATIONS
EVENT DETECTION

MAGNITUDE 5.3 EARTHQUAKE 100KM OFFSHORE TURKEY ACCURATELY DETECTED USING 2 STATIONS

On November 30, 2021, at 04:00:41, an earthquake of magnitude 5.3 hit approximately 100km offshore of western Turkey, with shaking felt in the nearby city of Izmir. Using two seismic arrays located on the coast line, SeismicAI’s system detected the event in real time, providing 16 seconds of warning time.

 

Izmir, Western Turkey

 

Location of earthquake, array stations, and Izmir

BACKGROUND

Western Turkey’s Izmir, a city of over 4 million people, has experienced several large earthquakes over time. The last major one was the  2020 Aegean Sea Earthquake, which hit approximately 70km southwest of the city. It had a magnitude of 7.0 and caused catastrophic damage, including over 100 casualties, thousands of serious injuries, and hundreds of destroyed buildings. Following the event, SeismicAI deployed a pilot earthquake early warning system that included two seismic arrays located close to the coast line aimed at rapidly detecting offshore incidents.

Timeline

On November 11, 2021, at 04:00:41, an earthquake of magnitude 5.3 – the largest incident since the pilot began – hit about 120km southwest of the city in the Aegean Sea. The closest station, located about 62 km from the epicenter, detected the event at 04:00:51. The second station, located about 124km from the epicenter, detected the event at 04:01:00. Just one second later, at  04:01:01, the system identified the event location and magnitude with sufficient accuracy to issue an alert, leaving 16 seconds of warning time before the S wave hit Izmir at 04:01:17. Since the system operated as a pilot at the time, warnings were issued only to selected users and not to the general public. 

Accuracy 

Our estimate of the epicenter location, 37.7124°N 25.7866°E, was highly accurate – only 15km from the catalog epicenter estimate of 37.7534°N 25.9719°E. In addition, our magnitude estimate of 4.9-5.4 was very close to the catalog magnitude.

This is the world’s first large, widely-felt earthquake to be detected in real time by just two seismic stations, while providing considerable warning time. It demonstrates the tremendous potential of SeismicAI’s array technology for fast and accurate detection of offshore events.