← Back to Gallery

Near-Real-Time Estimates of Fatalities Due to the M7.8 Earthquake on 6 February 2023 in Turkey

We issued a QLARM red alert of 3,000 to 6,000 fatalities 30 minutes after the large earthquake on 6 February 2023 on the East Anatolian fault. This estimate was based on a point source model of an estimate of M7.6, considering that it might be only an M7.4, as a different report suggested, and that the depth of the greatest energy release may have been deeper than 10 km. This alert contained the warning that the point source model used was a poor approximation. The following aftershocks suggested a complex pattern that did not allow the construction of a line source model during the first minutes after the earthquake. A month after this quake, ground observations, aftershocks, satellite images and moment tensors showed that the rupture was about 300 km long and could be approximated by a line source of two straight segments and that the depth could be modeled as 18 km. We used the following coordinates to define the two segments of the line source from the SW to a middle point and farther on to the NE end: 36.17E/36.14N, 36.95E/37.44N, 38.48E/38.11N. With assumed average local transmission of seismic energy and average soil conditions beneath buildings, and assumed main energy release at a depth of 18 km and M7.8, the number of fatalities are estimated as 76,000 to 115,00 for the M7.8 earthquake alone. At the time of this writing, the total fatality count of all earthquakes in the February 2023 sequence is at the time of this writing 54,000 and climbing. The purpose of our fatality estimates in near-real-time is to help first responders worldwide to decide whether or not to mobilize for helping to save injured. Although the fatality range issued within 30 minutes after the earthquake was an underestimate, the alert level was “red”, the highest urgency we can assign, sufficient to urge first responders to rush immediately to the scene.

Session: February 2023 Mw 7.8 Earthquake Sequence in Turkey

Type: Oral

Room: 201 A/B

Date: 4/19/2023

Presentation Time: 05:15 PM (local time)

Presenting Author: Max Wyss

Student Presenter: No

Additional Authors