Ground continues sliding, cracking in Napa following 6.0 earthquake

NAPA, Calif. (KGO) -- The earth's not shaking much anymore, but the ground keeps sliding in Napa and cracks have opened up everywhere.

These cracks appeared following the Napa earthquake, a process commonly referred to as afterslip.

United States Geological Survey geophysicist Jim Lienkaemper is measuring and recording the size of gaps throughout Napa. "In the last eight days, it's moved about two inches," Lienkaemper said, referring to a crack that opened on Cuttings Wharf Road. "It's slowing down a lot now, but it will keep moving over the next few weeks and months, there will probably be a few more inches of slip."

That is not the kind of news homeowners like Dave Allendorf want to hear. Scientists say cracks like the one found in Allendorf's yard are often slow to appear and the process can last anywhere from a month to a year.

"It's probably opened up 3 or 4 inches in the last week," Allendorf said.

According to Allendorf it is showing no signs of slowing down. The rupture extends beyond the pen for his horses and comes dangerously close to his water tank, inches from disaster.

"The cost to replacing that tank or having another well drilled is $25,000, easy," he added.

A number Al Owens is also familiar with. Afterslip caused the crack through his yard and busted his water line, destroying and draining his tank in the process.

"2,500 gallons worth of water broke all the valves off the tank when it moved," Owens said.

Two men with tough choices: Repair it all now, or wait.

The problem isn't exclusive to homeowners. The City of Napa's Public Works Department is doing its best to keep up and fill holes created by afterslip. The city has put up signs, warning drivers of the potential road hazards created by the shifting ground. According to Lienkeamper, the city may need more signs. Data collected, suggests there are more afterslips to come.

Also in Napa, despite some initial cracking and damage, two schools are set to reopen. Saint John the Baptist Catholic School in Downtown Napa was yellow-tagged, due to significant cosmetic damage. Crews expect to have the work done by Tuesday. Stone Bridge Charter School is also planning to reopen Tuesday. The building suffered cracks and fissures during the quake.

The Red Cross is opening an emergency assistance center for victims of the Napa earthquake. The center will open at the Napa Valley Marriott Hotel on Solano Avenue. It will be open from 10 a.m. to 7 p.m. every day. People affected by the August 24 quake can meet one-on-one with Red Cross caseworkers, who can help with damage assessment, they also be handing out relief supplies, food and water. There will be about 12 caseworkers at the hotel. Officials are expecting about 150 to 200 people to seek relief.