A magnitude 4.6 earthquake hit California's Santa Cruz Mountains early Thursday morning, the strongest since the 1989 Loma Prieta quake. The USGS confirmed that this quake was the largest in the mountain region since LomaPrieta, and it felt like the whole forest fell. Since the initial jolt, the USGS has not recorded any major aftershocks, but experts warn that there is still a chance of a larger earthquake following any magnitude 4 or 5 event. While scientists cannot predict when the next one will hit, their advice remains the same: Be prepared for when it does. The earthquake originated in the Santa Cruz mountains and caused significant damage to the area, usually starting at a magnitude 5, but in the mountains, the rules are different.