The tsunami poses a risk to the entire California coast. But how bad should a major strike be?
A single tsunami may not lead to a worst-case scenario in every region. However, in total, more than 680,000 Californians were in the tsunami danger zone during the day. Overall, there could be $12.6 billion in losses in California’s 20 coastal and Bayside County – this figure does not include damage to ports, ports, roads, basic facilities or other infrastructure.
There are two main scenarios for the tsunami. The first is the “Far-Far-Source” tsunami, which comes from a far-Far-Source tsunami, just like a major earthquake in Alaska. This will provide a wide range of warnings – six hours in Los Angeles and five hours in San Francisco – but can produce the highest level of flooding for much of the state.
Then there is the “near source” tsunami, which can wash the shore in just 10 minutes after the nearby earthquake – with little time to notify or evacuate.
Here are some scenes from different parts of California. Unless otherwise mentioned, the figures come from the California Tsunami Program, which is run by the California Governor Emergency Services Office and the California Geological Survey.
Southern California
The distant tsunami: If people evacuate half an hour after the official evacuation warning, more than 350 people could be killed or injured on the Southern California coast. These include about 200 casualties in Los Angeles County, about 80 in San Diego County, 60 in Orange County and about twelve in Ventura County.
The hypothetical magnitude of 9.3 in Alaska’s earthquake (similar to the terrible tsunami of the 1964 tsunami) would issue a six-hour warning; a large tember from Chile could provide a 13-hour warning.
The largest projected distant tsunami could bring waves of 15 feet average sea level to Marina del Rey, Marina Monica, Naples and the Gulf of Alametos. 14 feet elsewhere in the rest of Long Beach; 10 feet in Manhattan Beach, San Pedro and Los Angeles and Long Beach Harbor; 9 feet in Malibu, Redondo Beach and Palos Verdes Hills; 8 feet in Leo Carrillo State Beach.
These estimates were published by the California Geological Survey and published in the City of Los Angeles’ hazard mitigation program.
Damage estimates of distant tsunamis: More than $1.4 billion.
Near-source tsunami: Los Angeles’ tsunami program warns that Los Angeles may see tsunamis shift from its source to coastal areas in just 10 or 15 minutes. According to public documents, depending on the faults that break or where the underwater landslide is triggered, there may be 30 feet of locally generated tsunami heights in Avalon, Catalina Island. 24 feet in Palos Verdes Hills; 18 feet in two ports; 11 feet in Redondo Beach; 9 feet in Malibu; 8 feet in Long Beach and Santa Monica Pier; 7 feet in Manhattan Beach and San Pedro; 5 feet in Marina del Rey; 4 feet in Leo Carrillo State Beach.
In the city of Los Angeles, officials say the most disastrous situation will involve an underwater slope triggered by an earthquake because “we don’t know until the wave arrives,” said Jon Brown, assistant general manager of the city’s emergency management division.
Other vulnerable areas in Los Angeles County include the port and San Pedro and Long Beach. The city of Los Angeles has an estimated 23,000 residents in the tsunami that endangered the area. In Long Beach, the number is 31,000.
Central Coast
The distant tsunami: If people wait for half an hour to evacuate after official warnings, more than 230 people may be killed or injured. More than 130 casualties can be seen in Santa Cruz County. San Luis Obispo County, about 80 years old. The estimated potential casualty tolls are likely to be 16 in Monterey County and 7 in Santa Barbara County.
Damage estimates of distant tsunamis: More than $3.5 billion.
Near-source tsunami: Santa Cruz and Monterey counties may see tsunami within minutes of the earthquake’s landslide, documents from both counties said. “Even a mild earthquake could lead to a local source tsunami where the Monterey Bay submarine landslides,” the public document said.
A near-source tsunami can bring 15 feet of waves at sea level at the dock, 9 feet in the city of Marina, on the Salinas River; 8 feet in the Pajaro River and Sand City, northeast of Monterrey, on the moss landing in the city of Monterrey, according to data from the Hazard Mitigation Plan in Monterrey.
This kind of destruction will not be unprecedented. According to the U.S. Geological Survey, a major earthquake occurred in the Santa Barbara area in 1812, causing the tsunami to “destroy many coastal villages and destroy ships at the port.”
According to the California Geological Survey, the 1927 tsunami caused 7-foot waves, which was caused by an earthquake about five miles west of the coast of Santa Barbara County.
USGS said there is evidence that Santa Barbara, which often dates back to 160,000 years, suggesting that “future earthquakes could cause large undersea landslides and destructive tsunamis.”
Bay Area
The distant tsunami: If people wait for half an hour to evacuate after official warnings, more than 1,300 people may be killed or injured. About 500 of them are likely in San Francisco. In San Mateo and Marin counties, there are about 300; Alameda counties have nearly 200, and in Contra Costa County, 33 years old. In the northern part of the area, in Mendocino County, five people were killed or injured in this case.
The hypothetical tsunami-generated earthquake in Alaska could provide a 5-hour warning; a person in Chile could provide a 13-hour warning.
On the ocean beaches of San Francisco, a distant tsunami is expected to cause tsunamis 32 feet above average sea level; 31 feet in Pacifica in San Mateo County; 27 feet in Bolisnan in Marin County; 18 feet in Alameda; 14 feet in Sausalito and San Francisco water parks; 13 feet in Alcatraz; 11 feet in Richmond and Treasure Island, according to the California Geological Survey.
Damage estimates of distant tsunamis: More than $6.5 billion.
Near-source tsunami: In Northern California, near-source tsunamis can produce tsunamis of 9 feet above sea level, with an altitude of 9 feet above sea level. 8 feet in Pacifica; 7 feet in Sausalito; 6 feet in Ocean Beach; 5 feet in Alameda; 4 feet in Alcatraz, Treasure Island, Water Park, Redwood City and Richmond.
North Coast
Cascadia scene: Given the proximity of the Cascadia subduction zone, Del Norte County, the state’s northernmost coastal region, is likely to be more susceptible to tsunami risks than any other part of California. If people wait 10 minutes after the earthquake evacuates (shaking itself will be a warning of escape – more than 3,150 are at risk of being killed or injured by a tsunami in Delnot County, while neighbouring Humboldt County will have more than 720 dangers.
Floods may be as high as 30 feet higher than the average tide on the coast of Humboldt Bay and the Eureka area and up to 50 feet towards Crescent City.
“The large earthquakes in the Cascadia subduction zone may produce twice as many waves, especially in Crescent City,” Rick Wilson, former director of the California Geological Survey, said in a statement.
Damage Estimation: Del Norte County, home to Crescent City, may see more than $1 billion in losses. $22 million can be seen in Humboldt County, the home of Eureka.
