[t4h4]

Science article: https://www.science.org/doi/10.1126/science.ads4779

IMO this is the most interesting part: Postevent analysis revealed several limitations to the detection algorithms that have since been improved. First, the duration of monitoring has increased. At the time of the event, the algorithm only allowed updates to earthquake parameters for 10 s after first detection. The number of allowed updates was limited because there was a trade-off between more updates providing additional information for larger earthquakes and more updates introducing outlying single-epic data causing a large overalert. We now allow updates for 30 s and use other checks on the rate of variation in earthquake parameters before updating an alert. Second, there were a large number of noisy phones in the monitoring pool at the time of the Türkiye earthquakes. These high-noise phones triggered late, particularly after the P wave for the M 7.8 event, which had a slow start and complex rupture (31–34). The AEA system is now more selective about which phones are included in the monitoring pool. Individual phones determine their noise level when they become available for monitoring, and this noise level is factored into the detection algorithm. Third, many phones were receiving a BeAware alert and vibrating, which prevented them from triggering on the earthquake ground motion. The alerts now issued by Android EEW no longer cause phones that are detecting to vibrate.