If the Big One hits, everyone knows the drill: Duck, cover and hold.
But what about the Great Wave? As in, tsunami?
“I would grab my purse and leave all my crap and get in my Range Rover and get out of here,” said Mala Quatman, 60, of Danville, who was enjoying a recent sunny day. on Alameda Beach where the waves of the estuary barely lapped on the shore.
Cya Nicole, 22, of Oakland, who painted at Lake Merritt with her dog Simba, said she would be heading to the roof of her apartment building, a short walk away, as it is in a safe area.
“I’ve seen enough movies to know you should stay calm,” Nicole said. “You won’t get where you want to go if you panic, if you don’t keep your head straight.”
Quatman and Nicole were interviewed on a recent Friday at two of the many locations in the Bay Area identified by the new California Geological Survey maps as tsunami risk areas.
The bad news is that tsunamis are pretty common occurrences, but the good news is that the scariest ones – those that rise 25 to 30 feet upon entering the Golden Gate, rush across the bay, crash into the shores and swallow up city blocks – probably only happening once every 1,000 years or so. Of course, this millennial event could happen at any time.
“Tsunamis happen often. It is quite surprising. But most of the time, they’re only detected by tide gauges because they’re small, ”Rick Wilson, senior engineering geologist at the California Geological Survey, said in an interview.
But if there is only a 5% chance that the Bay Area will experience a massive tsunami in the next 50 years, people still need to plan as if tomorrow could bring the millennial event, Wilson said.
“The better informed the public, the more likely they are to save their lives and the lives of their families,” Wilson said, “and that’s what we want.”
When major tsunamis strike, the damage can be catastrophic. The most destructive to reach California in modern history occurred on March 28, 1964, according to the California Department of Conservation. During this event, “Several surges up to 21 feet high swept through Crescent City four hours after a 9.2 magnitude earthquake in Alaska, killing 12 people and leveling much of the city’s business district.” .
Over 150 tsunamis have hit California shores since 1800, but only a few besides Crescent City have had significant impacts.
More recently, ripples from the 2011 Tokuhoku earthquake and tsunami in Japan – which killed more than 18,000 people there – caused approximately $ 100 million in damage to ports and harbors in California, including Santa Cruz, and killed a man.
The Geological Survey has updated tsunami hazard maps since last summer to reflect a millennium event, including maps of Bay Area counties in recent months.
“The Japanese actually only predicted 100 to 500 year historical events, and it turns out they got their 1,000 year event. For us, it was kind of a call to watch and investigate and see what a 1,000 year event would look like for California, in order to protect its coast, ”Wilson said.
The updated maps are based on a “worst case scenario” such as a 9.3 magnitude earthquake near the Aleutian Islands in Alaska. Such a powerful tremor could project a series of huge waves for several miles moving at jet speed towards the coast of the State of Gold, arriving in about five hours.
“It may seem like a long time, but it will take about an hour for the National Tsunami Warning Center to issue a warning to California, then additional time for local authorities to determine if an evacuation is necessary,” Wilson warned. “Ultimately, if you are near the coast and experience strong tremors from a local earthquake or receive official notification to evacuate, move inland as soon as possible. “
While the three-story waves as they entered the Golden Gate would likely lose size and vapor as they advance further into the bay, they could still land up to 12 feet above the line. of normal waterline, flooding the western areas of Oakland, Berkeley and Richmond, as well as the San Francisco Marina district, according to Staci Morrison, spokesperson for the Department of Conservation.
The Treasure Island would be covered and most of Alameda would be inundated except for a small central part of the island.
Some places along the bay would be wiped out while others would be spared. All of Oakland International Airport would sink, but San Francisco International Airport would have to escape in good condition, with the exception of some wet runway edges.
Sections of Highways 880, 80 and 580 crossing parts of San Leandro, Oakland, Emeryville and Richmond could be soaked.
The Warriors ‘$ 1.4 billion Chase Center in San Francisco would be flooded, as would the Giants’ Oracle Park and much of the waterfront north of there.
And if the Oakland A’s ended up building a billion-dollar waterside baseball stadium at Howard Terminal in Oakland Harbor, it would be hit by powerful waves as well.
The tsunami would likely dissipate as it moved further south into southern Alameda County, San Mateo County and Santa Clara County. Around the bay, the height and distance of the inland surge would be affected by the depth of the land, Wilson said.
San José International Airport would stay dry as the waves should have narrowed to just a few feet by the time they hit the South Bay. The Googleplex in Mountain View and Yahoo’s headquarters in Sunnyvale should come out unscathed. Facebook’s campuses in Menlo Park appear on maps as just outside of potentially wet areas.
But, Wilson noted, “Because it’s a strong moving current, even if it’s only a foot high, it will knock you over and (the tsunamis have) killed people even a foot away,” he said. he declared.
And if that current does come, you’re better off getting away from danger than trying to get away and get stuck in traffic when a tsunami hits, he noted.
Tyler Everett, 33, of Berkeley, who ate shawarma wraps on the sands of Alameda Beach with his friend Jeannine Koewler, 33, of Seattle, fears chaos will ensue with the news of a tsunami imminent.
“I bet most people would get in a car. If that were to happen now, we jump in the car. I would probably go back to Berkeley. I’ll take my cat, ”he said.
Koewler joked that indecision could doom her, even with hours of warning.
“Honestly, I would die. Because I would go home and be like, “What do I get? And I would spend the next five hours packing my bags, ”she said.
Although Wilson said the massive new dikes under construction in Foster City are expected to repel a large tsunami, a promontory in Shorebird Park near where Prakash Das, 59, walks his dog along Beach Park Boulevard could be inundated. .
But Das would only have to walk about a block west to get to safety, according to state maps, so he likes his chances of survival.
“I’m a bit of a mathematician,” he says.