I think warning systems are one of the best new technologies for dealing with earthquakes.
The technology is pretty straightforward. You network seismic sensors together and create a system that can detect oncoming (and usually unnoticed) P-waves which have a higher velocity than the destructive S-waves that follow anywhere from 30 to 90 seconds later.
The distributed nature of the system ensures that any result is the product of multiple sensors producing the same data.
30 to 90 seconds is a lot of time. You could deploy receivers set accept the existing SAME codes and automatically send building systems into "Earthquake Mode" via simple relays. Virtually everything that would need to happen is already part of the programming of each affected system. In a lot of cases, you wouldn't even need to modify them in any significant way as they already accept inputs from external relays.
Once the alert goes out:
- Emergency messages are sent to all cell phone users - This system exists and is used for other emergencies.
- Fire station doors roll-up. - Add a simple sounding device and momentary contact to the existing door-opening circuit and you're done.
- Earthquake alarms sound in homes and small businesses - Weather radios that accept SAME codes are already programmed to do this.
- Earthquake alarms sound in major buildings - Fire alarm systems with voice evac are already customized and can accept new initiating devices and announcements with a software update.
- Emergency generators and fire pumps spin-up. Smoke handling systems activate. Stairwells are pressurized. - See above.
- Elevators go into "Fire Mode". All cars go to their recall floor, hold the doors open and refuse input. - This programming exists in every elevator installed in the past few decades. Activating a building fire alarm system will trip this anyway.
- Gas main valves are closed. - This is cheap and simple tech.
- Halt surgery - Voice evac / weather radios that accept SAME codes.
- Shut down industrial processes - Some combination of the above.