[ianburrell]

Google (and Apple) has been partnering with ShakeAlert from USGS for quake reporting on west coast of US. But that takes network of seismometers and detection system.

I could see smartphone seismometers being useful for areas that don't have all that. OTOH, if phones are useful seismometers, it should be possible to make cheap, dedicated ones.

[homebrewer]

The closest one (that I know of) is approximately 1000 km away, and it does provide data about earthquakes, but only after the fact. They already have some information sharing, because I usually look up the info on usgs.gov, but almost certainly not in real time.