Why one of the biggest earthquakes ever recorded caused so little damage
Despite its remote location, the size of the quake immediately brought potential danger of tsunami to a significant swath of the globe, including Japan, Canada and the United States. Tsunami alerts immediately went out, covering millions of people, including the entire U.S. West Coast.
But for all its fury, the quake ended up not being a catastrophe. Dangerous waves that rose more than 10 feet never materialized outside of Russia, and even there, officials had no reports of deaths, and damage appeared to be limited.
"In this case, we mostly dodged a bullet," said Mike Rademaker, harbormaster for the Crescent City Harbor, a place that saw deadly tsunamis both in 1964 with the Alaska mega-quake and 2011 when the great Japanese quake hit.
While those events represent worst-case scenarios, Tuesday's temblor represents a best-case scenario.
"With tsunamis, location and directionality is everything," said Nathan Wood, a tsunami scientist with the U.S. Geological Survey.
The area near the epicenter off Siberia's Kamchatka Peninsula did see damage, but it was sparsely populated. Video of the town of Severo-Kurilsk, on an island just off the peninsula, showed a building being swept away.
But for areas farther out, initial modeling suggests the tsunami's energy was directed into the open Pacific Ocean, roughly between Alaska and Hawaii, and had time to weaken before it hit more populated areas.
"It just kind of shot right between the two of those [states]," Wood said.
The tsunami "impacted the local community that was right next to the source [earthquake] where it happened," Wood said. "But for everyone else, it kind of just shot right down this empty hallway — in between the Aleutian Islands chain and the Hawaiian Islands — and so there wasn't really a whole lot in its way.
"So by the time it got to the West Coast, like California, Oregon, a lot of the energy had been dissipated," Wood said.
Russia saw tsunami waves as high as 16 feet, according to news wire reports, but tsunami heights maxed out at 4 feet in Crescent City, 3 feet in Arena Cove in Mendocino County, 2.7 feet at Port San Luis in San Luis Obispo County, 2.6 feet at Point Reyes in Marin County and 1.5 feet in Monterey. The totals were even smaller in Southern California.
The highest wave in the U.S. was 5.7 feet in Kahului, Hawaii, on Maui.
"It's a relatively good day," state Sen. Mike McGuire, who represents a large swath of the Northern California coast, said Wednesday.
The extensive alerts issued after the earthquake struck at 4:25 p.m. Tuesday PDT sparked concern across the Pacific, as scientists raced to forecast how extensive the tsunami could be. A magnitude 8.8 quake ranks as the sixth most powerful earthquake on record in the last 125 years.
But by Tuesday evening, the National Tsunami Warning Center's forecasts indicated that Crescent City would see a tsunami that would likely cap out at no more than 5 feet, and with places like San Francisco and Los Angeles harbor at less than 1 foot or so.
Dave Snider, the tsunami warning coordinator at the National Tsunami Warning Center in Alaska, said it might be too early to assess how much damage this tsunami did, but "it is true, maybe this one wasn't as bad as it could have been."
"If the focus of this tsunami's energy is not pointed right at your coastline, the impacts to you could be pretty limited," Snider said.
The magnitude of the earthquake is important, but it's "more about how much of that water moved, and what direction was that energy pointed at the coastline," Snider said. "In this case, it looks like maybe it just wasn't focused at the California coastline with that intensity of other known events."
There are other tsunami scenarios that pose far greater risks to California. One involves a near-shore tsunami, such as a magnitude 9 earthquake along the Cascadia subduction zone, just off the coast of California's North Coast, Oregon and Washington.
Depending on the strength and location of the quake, life-threatening waves could approach the coastline in as few as 10 minutes, perhaps not even enough time for an emergency alert to be issued, much less arrive on your cellphone.
Near-shore tsunami from other offshore earthquakes could result in waves of up to 6 feet above mean sea level at San Francisco's Ocean Beach; 8 feet in Long Beach and the Santa Monica Pier; 9 feet in Malibu and 30 feet on Catalina Island.
Read more: An earthquake just off California's coast poses dire tsunami risk for many communities
Another worst-case scenario involves a major earthquake in Alaska sending a tsunami to California. Maximum projected distant-source tsunamis could bring waves of 15 feet above mean sea level to the Santa Monica Pier and Marina del Rey and 32 feet at San Francisco's Ocean Beach.
Awareness of tsunami alerts has improved over the years in large part thanks to deep ocean pressure sensors that can detect tsunami that are overseen by the National Oceanic and Atmospheric Administration, said Eric Geist, research geophysicist for the USGS.
"There were several, fortunately, in operation right off the Kamchatka subduction zone," Geist said. "So we knew, really quick, that a tsunami — and a fairly sizable one — was generated."
One of the tragedies of the 2004 Indian Ocean tsunami was a lack of warning.
Helping matters is that this week's tsunami hit California when there was a lower tide.
The extensive warnings offered California officials another chance to handle a tsunami at a time when experts are urging both the public and government agencies to be more prepared.
In December, a tsunami warning from an earthquake about 30 miles from the Humboldt County coast prompted a decidedly uneven response across Northern California.
It was the first time the San Francisco Bay Area had ever received a warning of a "near-shore" tsunami with little time to evacuate, and the response demonstrated how the public had little awareness of whether they lived or work in a tsunami hazard zone.
In the end, only a tiny tsunami, measured at 5 centimeters, was recorded in December.
Even Tuesday night, there were problems. The California Geological Survey recently updated its tsunami hazard map — showing places in California that are at risk of tsunami inundation. The state's website crashed, yet again — a repeat of the website failing during the December 2024 tsunami warning, although this time, media outlets, including The Times, made interactive versions available.
But other efforts at preparation against tsunami have borne fruit.
In Crescent City, officials noted that the one dock that structurally failed — "H" dock — during Wednesday morning's tsunami actually worked as designed.
"'H' dock was engineered as a wave-and-current attenuator with closely spaced pilings, which are specifically designed to disrupt and dissipate tsunami energy before it reaches the Inner Harbor," Rademaker said. "So its sacrificial role in the overall design appears to have functioned as intended, absorbing the brunt of the surge, and helping to protect the more interior docks."
Crescent City Harbor was totally destroyed during the 2011 tsunami, and also suffered damage from a 2006 tsunami — events that each took a three-year rebuilding process. The statewide total in damage from the 2011 tsunami was estimated at more than $100 million. One person in 2011 died after being swept into the sea while taking pictures of the tsunami. The Crescent City tsunami in 2011 topped out at 8 feet.
The 1964 Alaska earthquake set off a catastrophic tsunami that devastated Crescent City, washing away 29 blocks and killing at least 11 people. Surges reached 21 feet above the average low tide.
Sign up for Essential California for news, features and recommendations from the L.A. Times and beyond in your inbox six days a week.
This story originally appeared in Los Angeles Times.
Solve the daily Crossword
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Boston Globe
10 hours ago
- Boston Globe
What to know about the earthquake that shook the New York area Saturday night
There were no initial reports of serious injuries or significant damage in New Jersey or across the Hudson River in New York City. City officials said that as of late Sunday morning they had not been called to respond to any building-related issues. The Big Apple has more than 1 million buildings. Many posts on social media reported the ground rumbling, and the U.S. Geological Survey reported more than 10,000 responses to its 'Did You Feel It?' website. Advertisement Though people in the United States might associate earthquakes more often with the West Coast, scientists say these types of incidents on the East Coast are not unlikely. Get Starting Point A guide through the most important stories of the morning, delivered Monday through Friday. Enter Email Sign Up How frequent are earthquakes in the New York area? The area feels an earthquake about once every couple of years. 'The northeast part of the United States does not see large earthquakes very often,' said Jessica Turner, a geophysicist with the National Earthquake Information Center, which is a part of the USGS. Since 1950, only 43 other quakes of this magnitude and larger have occurred within 155 miles (250 kilometers) of Saturday's event, according to the USGS. A much larger, 4.8-magnitude quake that struck in Tewksbury, New Jersey, a little farther west of the city, in April 2024 was felt as far away as Boston and Baltimore. Some flights were diverted or delayed after that quake, and Amtrak slowed trains throughout the busy Northeast corridor. Advertisement A smaller, 1.7 magnitude earthquake that hit the Astoria section of Queens, New York, in January 2024 stirred residents. The region sees a more damaging one only a couple times a century, if that. New York was damaged in 1737 and 1884 by earthquakes, according to USGS data. How do East Coast earthquakes compare with West Coast ones? The difference between East Coast and West Coast quakes lies in the 'mechanism,' said seismologist Lucy Jones. California is at the edge of the San Andreas fault system, which has two tectonic plates: the Pacific Ocean plate and the North American plate. Two plates move and push to build up stress, meaning earthquakes happen relatively frequently. New York falls in the middle of a plate, far from the nearest boundaries in the center of the Atlantic Ocean and in the Caribbean Sea — resulting in residual stresses and making it difficult to predict where earthquakes will occur. The area is also home to the well-known Ramapo Fault line. Geologists have not seen evidence that would suggest it has had a large earthquake in some time, but there have been smaller ones. Saturday's quake cannot necessarily be associated with this fault, experts say. The same size earthquake is felt over a much larger area in New York than it would be in California. 'The rocks on the East Coast are particularly cold and hard and therefore, do a better job of transmitting the energy,' said Jones. In California, the various faults are more akin to a broken bell, which doesn't transmit energy as well. Does this signal more to come? Every earthquake makes another one more likely, but within a range, scientists say. Advertisement 'At just 3.0, the chances are there will not be another felt event,' Jones said, estimating about a 50-50 chance there will be no activity that can be recorded. 'Most likely is an unfelt, magnitude 1 or 2 aftershock.' Associated Press writers Julie Walker in New York City and Michael Hill in Altamont, New York, contributed.
Scientific American
14 hours ago
- Scientific American
3.0 Magnitude Earthquake Rumbles New York City Less than 2 Years After the Last One
New York City and the broader East Coast were shaken by a 3.0-magnitude earthquake late on August 2, reminding locals of a significantly larger quake that startled the region in April 2024. The earthquake, which occurred at 10:18 P.M. local time, was centered near Hasbrouck Heights, N.J., about 10 miles from downtown Manhattan, at a depth of about six miles, according to the U.S. Geological Survey (USGS). Neither New York City nor Bergen County, N.J., where Hasbrouck Heights is located, reported major damage or injuries, according to the New York Times. Earthquakes large enough to be felt are uncommon in the eastern U.S. 'It's a pretty quiet part of the country,' Benjamin Fernando, a seismologist at Johns Hopkins University, told Scientific American in 2024. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. However, small earthquakes, with magnitudes of 2.5 or lower, are quite common in the region. The earthquake magnitude scale is logarithmic, with each whole-number increase in magnitude representing a 10-fold increase in the size of the seismic waves it produces. That means the 2024 earthquake was 63 times bigger than the August 2 event. (The massive earthquake that rattled Russia just days ago, a magnitude 8.8 event, produced seismic waves a stunning 630,000 times larger in amplitude than the August 2 New Jersey quake.) In turn, the August 2 event created seismic waves with about three times the amplitude of a 2.5 magnitude event that represents the high end of typical activity in the region. The August 2 earthquake occurred nearly 40 miles away from the 2024 earthquake, which is too far away for it to be considered an aftershock of the previous event, although the 2024 quake does continue to spur aftershocks, according to the USGS. The USGS attributed the August 2 earthquake to 'faulting at shallow depths in the crust' and noted that it did not occur near a plate boundary. The region has many faults, but these fractures in Earth's crust are very old—they date to the era when the Appalachian and Blue Ridge Mountains were built, hundreds of millions of years ago. Although the East Coast is not prone to large earthquakes like the West Coast, the rattling of an East Coast quake is felt more broadly because the hard bedrock of the region transfers seismic energy more efficiently than the heavily faulted West Coast bedrock.
San Francisco Chronicle
18 hours ago
- San Francisco Chronicle
Bay Area study finds overlooked earthquake risk from prolonged shaking
Some parts of the Bay Area are prone to an underexplored earthquake risk, according to a recent study led by U.S. Geological Survey scientists. In these places, quakes can produce long periods of shaking — something unaccounted for in existing building codes, but which can have devastating impacts. 'Prolonged shaking was very important in Northridge,' said Emily Brodsky, a professor of earth and planetary sciences at UC Santa Cruz, referring to a magnitude-6.7 earthquake that struck the Los Angeles area in 1994. The quake killed at least 57 people and damaged over 100,000 structures. The authors of the new study analyzed ground motion records during 49 Bay Area earthquakes, occurring from 2001 to 2024. The quakes ranked in strength from magnitude 3 to magnitude 6. In total, the scientists probed about 7,400 ground measurements from seismometers across the region. They identified locations where earthquakes resulted in longer periods of shaking than expected. The authors reported that the type of rock or soil that underlies a region is a major risk factor in longer-duration shaking. 'We talk a lot about the bay mud,' said study author Evan Hirakawa, a research geophysicist with the U.S. Geological Survey's Earthquake Science Center. 'This is really young claylike mud that's around the San Francisco Bay. That's where it's known to shake a lot more intensely.' During the 1989 Loma Prieta earthquake, the double-decked Cypress Structure collapsed in West Oakland, killing 42 people. The freeway was built on soft bay mud, Hirakawa said. The Santa Clara Valley, the San Francisco Bay shoreline and Santa Rosa also registered long-duration shaking, according to the study. Some locations, like Foster City, even experienced 'ringing,' a phenomenon in which seismic waves resonate to produce longer periods of shaking. By contrast, stations on hard bedrock generally experienced less cumulative shaking. That includes parts of San Francisco and in the East Bay Hills. This is because granite or hard bedrock shakes much less than young, soft sediments. 'Think about if you were to flick a brick versus a bowl of jelly,' Hirakawa explained. The authors reported that long-duration shaking was also affected by how earthquakes ruptured underground and how seismic waves traveled to a particular site. One limitation of the work is that the authors only investigated small- and moderate-sized earthquakes, which are less complex than stronger quakes. 'We need to be thoughtful about how the findings apply to larger and more destructive events,' said Jack Baker, a professor of civil and environmental engineering at Stanford University who wasn't part of the study. Still, Baker highlighted the importance of investigating shaking duration. 'In the engineering world, we really focus on the peak intensities and the peak forces that that produces,' Baker said. 'These metrics around duration are definitely relatively less studied.' The findings from the new study aren't surprising, said Brodsky, who also wasn't part of the research. But the results are still valuable: 'When you actually have to build a building, you don't want to just know, in general, it rings more in the basins,' Brodsky said. 'You'd like to know how much it rings more, in this basin."
