Estimates of the number of fatalities within minutes for the three great earthquake disasters in 2023

Three major earthquake disasters occurred during 2023: Turkey M7.8, February 6, Morocco M6.8 August 9, Afghanistan M6.5 November 10. The final cost in lives reported were 59500, 2946 and 1482 fatalities, respectively. QLARM (Quake Loss Alerts for Recovery and Mitigation) is a computer tool used to estimate damage, fatalities and injured for potentially fatal earthquakes worldwide. Using QLARM (e. g. Wyss 2014, 2023), my estimates were the only red alerts for these earthquakes issued within minutes. Red alerts are the highest level of urgency that can be given. The fatality estimates were 2000-6000 for Turkey, 100 to 1000 for Morocco, and a total of 500 to 2000 for the Afghanistan earthquake swarm (three messages within 4 days). These alerts were distributed by SMS to anyone who signed up to receive the QLARM alerts (signup link given below) free of charge. These three red alerts were received by subscribers within 30, 31, and 18 minutes, respectively. The USGS hypocenter and magnitude estimates arrived within 29, 24 and 30 minutes, respectively. The QLARM fatality estimates were based on the first information on source parameters for these three earthquakes available worldwide, which came from GFZ (Geophysicalisches ForschungsZentrum, Potsdam) after 7, 8 and 7 minutes, respectively.

The purpose of the QLARM alerts is to activate first responders and government in case of earthquake disasters, and also to furnish quantitative information for the many large magnitude earthquakes that were not likely to have killed many and therefore for which an international response was not needed. During the year 2023, QLARM issued a total of 60 alerts with a median delay of 22 minutes.

The chief reason for the initial fatality underestimates for the Turkey and Morocco disasters was that the source was assumed to be a point, which was appropriate only for the Afghanistan sequence, where the fatality estimate was correct. The information on the lengths, direction and endpoints of the rupture became available only later for the Turkey and Morocco cases. Using line sources for the Turkey and Morocco earthquakes brings the fatality estimates closer to the reported ones, but they are still lower than what was reported, most likely due to the construction of buildings in these two regions, which are apparently weaker than assumed in the QLARM data set. The most important means of improving near-real-time estimates of earthquake losses is to implement rapid estimates of rupture lengths and azimuths.

References:

International Centre for Earth Simulation (ICES). QLARM sign-up. https://www.icesfoundation.org/Pages/CustomPage.aspx?ID=122, Retrieved January 09, 2024.

Wyss, M. (2014). Ten years of real-time earthquake loss alerts. In Earthquake hazard, risk and disasters (pp. 143-165). Academic Press.

Wyss, M. (2023). Quantitative Earthquake Loss Estimates the New Frontier. Seismological Research Letters, 94(6), 2569-2574.