Simulated Earthquake Early Warning for M6.9 Loma Prieta, CA Earthquake
The alerts at 16 seconds into the earthquake with an estimated magnitude of 6.0. The Cell phone apps alert polygon has expanded well beyond the limits of this map. The light blue polygon denotes the first WEA alert. For both the Marina district and the Nimitz freeway, the WEA alerts arrive before shaking is felt. Other symbols are the same as the previous figure.