It was part of a statewide campaign to prepare for earthquakes known as the Great California ShakeOut event, which happened on Thursday, October 17. A total of 67 Metrolink stations within Orange, Los Angeles, San Bernardino, and Riverside counties took part in the exercise.
The Metrolink passengers aboard train number 308 were informed via intercom while the train made its way to Pomona station that they should expect the train to slow down and participate in an earthquake drill. This yearly affair is meant to help Californians learn more about how they can prepare themselves against earthquakes. Flyer printing can be used to spread the message for such campaigns.
According to Meredith Yeoman, a spokesperson for Metrolink:
“Trains can be stopped, slowed down, or not affected at all, depending on how close they are to the epicenter and how strong the earthquake is.”
This is enabled by an automatic braking system known as a positive train control system that uses GPS to stop trains in case of seismic activity. Conductors have one minute within which to reduce their speed to 20 miles per hour before stronger secondary earthquakes come.
The early-detection earthquake warning system operated by the U.S. Geological Survey's ShakeAlert is linked with Metrolink's Pomona positive train control lab. If it records an earthquake of magnitudes higher than 5.0, ShakeAlert alerts Metrolink to the activity in a matter of seconds, enabling conductors to respond appropriately.