My understanding is that "precursor event" has a specific meaning in seismology, i.e., sentence 2. is more restrictive than 1. But I'm no expert, so I'll be gr

My understanding is that "precursor event" has a specific meaning in seismology, i.e., sentence 2. is more restrictive than 1. But I'm no expert, so I'll be grateful if someone with the knowledge could clarify.