I am riding the Caltrain south, we slowed to a snail's pace and they said it would take 2hr+ to get to Palo Alto (from SF).
A bunch of people got off, and then the conductor comes back on the PA system to say the speed limitation had been limited and "we'll be going back to 79 MPH, hold on to your hats"
A 7.0 earthquake nearby is a pretty good reason to slow down trains, regardless of propulsion.
The easily found page about Caltrain's response to earthquakes [1] doesn't include magnitude 7, but also doesn't include earthquakes more than 100 miles from the tracks either. So I think a brief reduction in speed is reasonable for a large quake within the larger area and quickly ending the restriction as its confirmed the quake was outside the policy scope.
A bunch of people got off, and then the conductor comes back on the PA system to say the speed limitation had been limited and "we'll be going back to 79 MPH, hold on to your hats"