There's a few people in my replies saying "why do you need an alert, it is obviously an earthquake" so as someone who has only felt a couple: is this true? In my experience it's been a "wtf was that?" and checking if a truck hit my building or something
Comments
https://natural-resources.canada.ca/stories/simply-science/takes-only-seconds-protect-yourself-earthquake
https://earthquakes.berkeley.edu/research/eew_elarms.html