KQED's CY MUSIKER: Safety experts and seismologists have long dreamed of an early warning system for earthquakes. That dream is now a reality thanks to UC Berkeley seismologists and BART.

Last month, the rapid transit system hooked itself up to a network of more than 200 seismic monitoring sites statewide from the Oregon border to Monterey County.

That could give BART up to one minute to automatically brake its trains if the network detects an earthquake -- perhaps preventing a derailment and casualties.

Peggy Hellweg is a seismologist at UC Berkeley who's worked on the project. And John McPartland is the BART board president and was also a BART safety specialist for six years.

Ms. Hellweg -- let me start with you. Explain how this monitoring system works.

PEGGY HELLWEG: Our ground motion instruments detect the ground motion. They send it to us as quickly and as reliably as they can. We process that information and pass on ground motion summaries to BART every second.

MUSIKER: And John McPartland -- This is an automatic system. Why is that better than a warning system like a flashing red light that someone at a control center can react to?

JOHN MCPARTLAND: That's a perfect question, and the reason is, you have to depend upon the reaction time of the central manager in order to see a flashing light and send that information out to train controllers. The first time we had this exercise was, I think, four years ago, and from the time the alarm came until the train controllers received their orders was 22 seconds.

MUSIKER: So by then, the earthquake might have hit already, and the warning would have been for naught.

MCPARTLAND: Absolutely. And so what this system does is automatically, it will end up sending signals to the trains for the trains to automatically decelerate at normal speed.

MUSIKER: And Ms. Hellweg, if we think back to the Loma Prieta earthquake of 1989, how much time would a monitoring system have given BART trains to slow down?

HELLWEG: About 20 to 25 seconds.

MUSIKER: And Mr. McPartland, how much speed could you shave off if you had 20 seconds to slow down the trains?

MCPARTLAND:  A 70 mph train would be down to 13 mph.

MUSIKER: There was an earthquake this morning with a preliminary magnitude of 2.7 near Berkeley. Did that trigger the system?

MCPARTLAND: Absolutely not.

MUSIKER: What's the cutoff then for size of the earthquake?

HELLWEG: So, the honest answer to that is that it's not the size of the earthquake at this point. It's the intensity - the strength of ground shaking.

MUSIKER: And Ms. Hellweg, BART is the first transit system in the U.S. to adopt this monitoring system. What are the prospects for hooking up other transit systems or hospitals or tall buildings with elevators or fire stations that need to open their garage door to the same system of seismic monitors?

HELLWEG: This is a demonstration system at this point, but in order for this to really be a statewide or a West Coast-wide system we need to have more money invested in it.

MUSIKER: I understand the total bill would be about $150 million, and I think you need more help from the Congress, from federal funding for that. Your colleague Richard Allen is in Washington D.C. today making a presentation to Congress. What are the prospects for more funding?

HELLWEG: That's almost as bad as earthquake predictions. It's hard to say what Congress is going to do in this era when you ask them for money. I think they are getting a really good deal for the money if they invest it.

MUSIKER: And Mr. McPartland, how do you feel about being a test subject?

MCPARTLAND: I think that this is delightful. Think what kind of a model this will end up being if we have a major earthquake and we are able to stop trains, prevent the injuries, and as far as this serving as an adoption for getting the funds that we need for the sensors, and having other transit agencies adopt this policy - that's kind of like a no-brainer to me.

MUSIKER: Thanks so much to you both for talking to us.

HELLWEG: Thank you.

MCPARTLAND:  Thank you for giving us the opportunity to share this with you.

MUSIKER: Peggy Hellweg is a seismologist at U.C. Berkeley, and John McPartland is the BART board president.