Figure 4
From: The Limits of Earthquake Early Warning Accuracy and Best Alerting Strategy
Deaggregated earthquake alert outcomes for San Francisco. Each earthquake in the UCERF3 catalog is categorized into (from left to right) a correct no alert, missed alert, correct alert, or false alert for 2%, 5%, 10%, or 20%g for a user located in San Francisco. Text on left hand side lists what percentage of the total number of events in the catalog does (Yes) or does not (No) trigger an alert. Because strong ground motions are more infrequent than weak shaking, fewer earthquakes trigger an alert for 5%g than for 2%g, and so on. On the right hand side, we ignore the correct no warning case and tally what percentage of the remaining events are classified as correct alerts, false alerts, or missed alerts. In almost all cases, the most common outcome a user will experience is a missed alert. This behavior becomes more pronounced at higher ground motion thresholds.
