I got a notification (in Santa Cruz) that mentioned a magnitude (4.9), a distance (~30 miles), and that I should expect mild shaking. I saw the notification a few seconds after it arrived, because my phone was making a weird noise, and the shaking started immediately after I read the notification. It was probably the strongest earthquake I have experienced in the ~5 years here, but there were several similar earthquakes every year when I was living in Chile.
If you send notifications for minor earthquakes like this, an estimate of the intensity is mandatory. At least in countries like Chile (and Japan?) where earthquakes are common. Otherwise people will learn to ignore them as false alarms.
I'm thinking the best thing to do is threshold the notifications to ~5 or above, so they're worth paying attention to, and a certain distance of course. Not an expert though. 5 is major enough to want to know isn't it?
I'd also say the average person has no intuitive sense for earthquake magnitudes and giving a somewhat precise number wouldn't affect their behavior the way a broad category warning like mild, moderate, severe, and catastrophic would.
I suppose the people getting these notifications really just want to know if they should scramble for safety immediately.
If you send notifications for minor earthquakes like this, an estimate of the intensity is mandatory. At least in countries like Chile (and Japan?) where earthquakes are common. Otherwise people will learn to ignore them as false alarms.