NAPA (KRON) — It has been one year since the devastating 6.0 earthquake that rocked Napa and the surrounding area.
The South Napa Quake was the largest earthquake in the Bay Area in 25 years. And it gave geologists a rare opportunity to study a big quake up close.
2014’s magnitude 6.0 quake in Napa struck eight miles underground at 3:20 a.m. on August 24. By 9 a.m. that same day, USGS geologists were in Napa.
The first thing they looked for were cracks in the ground where the earthquake might reach the surface. They didn’t have to look very long.
Large ruptures were found in roads, fields, and driveways. according to USGS Geophysicist Tom Brocher.
“The ground in some places moved up to 18 inches,” Brocher said. “That sort of surprised us because this kind of earthquake, you wouldn’t expect to find any cracking.”
But that wasn’t all. A week later, geologists noticed that the ground was still shifting.
“In some places that didn’t crack at all during the earthquake, there was movement up to 14 inches in the week following,” Brocher said.
Brocher said they aren’t exactly sure why the earth kept shifting. It could be because the fault is so big that most of it moved during the quake, and the rest was slowing catching up.
He also said it’s possible that a year later, the ground in Napa could still be moving albeit very slowly. The other thing that surprised researches about this earthquake was the aftershocks, or lack there of.