The phone call came at 6:30 a.m., one of hundreds of automated emergency calls to coastal Sonoma County residents just hours after the devastating earthquake in Japan: There's a tsanami warning and you should evacuate.

"I went down to make sure my sailboat was tied up, we collected some important papers and went up to Salmon Creek to watch," said Michael Stafford, who lives on Bayflat Road in Bodega Bay. "I think both me and my wife consider it a wake-up call."

The images from Japan are devastating, with thousands dead and towns wiped out. In Bodega Bay the wave launched from the magnitude 9.0 quake was noticeable, draining Bodega Bay and then filling it quickly.

But it did not come close to any of the homes along the flats of the broad bay, which was at low tide and is also protected by a jetty and Doran Beach.

So just what is the risk to the Sonoma County coast?

"The only flat land areas are Doran Beach, Bodega Bay, the entrance to Salmon Creek and Jenner. ..in those areas there is some exposure," said Christopher Helmgren, assistant county Office of Emergency Services coordinator. "In the worst case, 700 homes."

Even in a worst-case scenario, the topography of the Sonoma County coast means there is little risk to widespread damage from a tsunami.

"This is a safe harbor, the best on the West Coast," said Steve Anello, a fisherman whose home also is on the bay flatlands.

"But if it had been high tide, the water may have come across the road," he said of the March 11 wave.

Seismologists say it would take a major quake greater than 8.5 in Alaska or Chile or in what is called the Cascadia subduction zone off the coast near Eureka to produce a large tsunami for California.

The San Andreas Fault is dangerous because it runs directly under Bodega Head, but it is not a threat to create a tsunami because it moves horizontally and not vertically, said Dave Oppenheimer, a seismologist with the U.S. Geological Survey in Menlo Park.

In comparison, the quake in Japan had a large displacement of ocean floor that created a tsunami, which devastated Japan and sent a wave across the Pacific that focused its force mainly on South America. Noyo Harbor in Fort Bragg, Santa Cruz Harbor and Crescent City suffered the most serious California damage.

"The good news is you look at the California coastline and most people do not live near the ocean, and if they do, it is not in low-lying areas," Oppenheimer said. "It is a pretty good situation from a tsunami standpoint."

The Sonoma County Office of Emergency Services used data from the state Emergency Management Agency a year ago to create maps showing how far a tsunami might come ashore.

The maps show most of the surge would cover beaches and bounce off the bluffs that line the Sonoma coast, with no damage.

However the maps also show the few low-lying areas that are at risk. That includes Doran Beach, Highway 1 at Scotty Creek near Sereno Del Mar and 700 buildings bordering Bodega Bay, Salmon Creek, the Russian River at Jenner and at the Highway 1 bridge and Port Sonoma at the mouth of the Petaluma River.

On March 11, the occupants of those 700 homes and buildings received an automated call with advice to evacuate, Helmgren said.

In Bodega Bay, the surge measured 3 feet, 2 inches by the National Oceanic and Atmospheric Administration.

Crescent City harbor had the most damage and also the largest surge at 8 feet, 2 inches, but Santa Cruz harbor also was hit hard.

"Crescent City always gets it; it is a tsunami magnet. Even the smallest tsunami will hit it — the way the coast line is shaped and how the harbor is built," said John Largier, a professor of oceanography at UC Davis' Bodega Marine Lab.

Most in Sonoma County's affected areas, however, said they feel safe, but are not dismissive.

"It makes you ponder ... it was pretty crazy in Santa Cruz," said Patrick Welch of Oakland, who was checking his Salmon Creek rental home Thursday.