I'll take a shot.
Radio with real people at the console is very dynamic at reporting on any event. Unfortuneatly, the cancer of voice tracking makes the purpose of immediate information via broadcast radio moot. As more and more stations resort to the "magic" of the computer, and the release to the unemployment rolls of the live person at the microphone, the local radio station becomes irrelevant to any actual event. When the guy in Milwaukee records his show for San Diego reporting temps in the 70's and clear skies a dozen hours before that voice is heard, and everyone at the local station has gone home or to the unemployment lines, there is no option for immediate response to an earthquake, mass killing, beached whale, or mayoral resignation. The lights may be on, but there's no one home. The automation and the dial out remote control will keep the "content" flowing. EAS will interrupt the normal day with it's "belch, belch, belch, chirp, chirp, chirp" nonsense, but people seeking real time information will tune their radios to whomever happens to be providing actual information of the moment. There aren't very many stations that do that these days after 10:00 AM.
Terrestrial commercial broadcast radio has become an automated jukebox without the ability to serve the public interest. The demand of increased profit on decreasing involvement in the community of listenership has destroyed the medium. It won't soon be back, if ever.
Your best bet in an earthquake situation is to have sufficient food and water in storage, and a place to stay outside away from things that can fall on you. Don't rely on radio to give you any guide. The computer only knows what to play from its last program update.
"Clear and sunny in San Diego, and the time now is 1/2 past the hour."
Take your earthquake and move outside. Don't expect any help from your local broadcaster serving the public interest, but expect Michael Savage to tell you what a poon you are for whining about it. That's what gets ratings these days. Ya' know?