New geological research indicates that the West Napa Fault, which caused the destructive and deadly 2014 Napa quake, may be nine miles longer and potentially much deadlier than previously thought.

This past August marked the nine-year anniversary of the 2014 Napa earthquake, which killed one person, injured 208 more, and did at least $400 million in damages to that NorCal region. That 6.0 magnitude quake was the largest the Bay Area has seen since the 1989 Loma Prieta earthquake, but we’re now learning it could have been much worse. That’s because, as the Chronicle reports, geologists have discovered that the West Napa Fault that caused the earthquake is likely nine miles longer than they’d realized.

The West Napa Fault had generally been considered to be about 35 miles in length, stretching from south of the city of Napa northward to St. Helena. New research from United States Geological Survey geologist Belle Philibosian indicates the fault actually stretches nine miles further north to just past Calistoga. That means that a rupture on the fault could potentially cause a 7.0 magnitude earthquake, which would be a bigger tremor than Loma Prieta.

“The northward extension was a little bit of a surprise,” Philibosian told the Chronicle. “We didn’t necessarily anticipate that there was an additional section of fault.”

Philibosian’s research is not yet published, so the findings could be updated with forthcoming additional academic review. But the Chron also spoke with other geologists, and there is an emerging consensus among them that the West Napa Fault probably does extend further north than they'd realized.

So let this serve as a reminder, particularly if you’re in Napa or Solano County, to get your earthquake “go bag” ready for if and when a natural disaster strikes. It’s a lazy holiday week, and a perfect time to take on easily overlooked projects and errands.

Related: 6.0 Earthquake Hits Near Napa, 120 Injured [SFist]

Image: Cullen328 via Wikimedia Commons