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Yahoo
4 days ago
- Climate
- Yahoo
Tsunami surprised Crescent City, caused $1 million in damage to harbor, officials say
Poor H Dock. When 4-foot tsunami waves crashed into the Crescent City Harbor in rural Northern California last week, the dock nearest the harbor's entrance — which was designed to absorb the brunt of the surge energy — took a beating. State Sen. President Pro Tem Mike McGuire, who represents the North Coast, called H Dock "a sacrificial lamb." And the Crescent City Harbor District said in a statement that the dock "functioned as designed — sacrificing itself to protect other infrastructure." But despite state and local officials' relief over how well the deck performed during the storm, it appears the damage to the harbor in the small city in Del Norte County — which calls itself "Comeback Town," because of its history with tsunamis — was worse than initial assessments suggested. Harbor officials now estimate the pounding waves on July 30 caused $1 million in damage to the harbor, which was rebuilt to be "tsunami resistant" after it was destroyed in a 2011 tsunami. "At first glance, the damage appeared modest" on H Dock, the Harbor District said in a statement Tuesday. Further assessments, however, found severe impacts below the water line to infrastructure "that supports the safe and functional operation of the harbor." Added Harbormaster Mike Rademaker: "The visible damage only tells part of the story." The tsunami, which followed a massive 8.8-magnitude earthquake off the sparsely-populated eastern coast of Russia on July 29, triggered alerts in Japan, Canada and along the entire U.S. West Coast. Ultimately, it did little damage outside of Northeast Russia, where it nearly destroyed a floating pier at a submarine base. Read more: Why one of the biggest earthquakes ever recorded caused so little damage Crescent City, a low-lying and uniquely tsunami-prone town of about 6,200 people, appears to have felt the most impact in California. At around 2:40 a.m. on July 30, surging waves caused H Dock's floating concrete decking to lift along its pilings, according to the Harbor District. As the water continued to rise, the structure could not support the decking. It was temporarily submerged, "resulting in segment separation and progressive structural failure," the Harbor District said in a statement last week. In a statement Tuesday, harbor officials said the incident illuminated "a new vulnerability in floating dock design: a previously underrecognized hydrodynamic failure mechanism." Video footage and data modeling from July 30 point to "a fluid dynamics effect on docks that has rarely been captured on video." The tsunami accelerated currents beneath the floating decking of H Dock, creating a zone of low pressure that "produced a downward force strong enough to overcome the dock's buoyancy, pulling the structure downward into the water," the statement read. "This is similar to the way an airplane wing generates lift — but in reverse," Harbormaster Rademaker said. "Instead of lifting the structure up, the water moving rapidly under the dock actually ducked it down. It's a dramatic and under-appreciated mode of failure." Harbor officials believe that electrical conduits through the center of H Dock's decking were badly damaged, as were potable water lines. Fire suppression plumbing lines were ripped apart. The tsunami waves also deposited a large amount of sediment and debris throughout the harbor basin. Extensive dredging operations will be required in order to restore safe depths for boat navigation, harbor officials said, adding that repairs will be "more costly than comparable land-based work" because it of the specialized labor needed. Harbor officials said Tuesday that they are working on a tight deadline to assess the damage. California law requires city and county governments to declare a local emergency within 10 days of a disaster as a prerequisite for requesting state or federal assistance. The Del Norte County Board of Supervisors "is expected to issue such a proclamation later this week," the Harbor District statement read. No boats were damaged in last week's storm, and no injuries were reported. In 2011, a tsunami that followed a devastating earthquake in Japan caused $50 million in damage to the Crescent City Harbor. The storm damaged numerous boats, which were repeatedly slammed against docks and each other. The inner boat basin was completely reconstructed to be more tsunami resilient. Thirty-inch steel pilings replaced the 16-inch pilings used in the previous dock structure and were driven between 21 and 37 feet into bedrock, compared with just 10 feet in the previous design, according to the Harbor District. H Dock was designed to bear the brunt of storms, with closely-spaced pilings designed to absorb and dissipate energy before it reached interior docks. State and local officials said the design prevented impacts from last week's tsunami from being much worse. 'The infrastructure built after 2011 saved vessels and lives,' Rademaker wrote. 'Now, we have a chance to take the design to the next level. We're not asking for a blank check to return to the status quo, we're taking the opportunity to use what we've learned to build smarter." Crescent City is uniquely susceptible to tsunamis for many reasons, including exposure — it is low-lying and juts out into the Pacific — and the bowl shape of the continental shelf, which traps the energy of tsunamis and bounces waves back and forth. Including last week's surge, 42 tsunamis have been recorded in Crescent City since the first tide gauge was installed in 1933. Crescent City earned its Comeback Town nickname in 1964, after a tsunami killed 11 people and destroyed 29 city blocks, forever transforming downtown. 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.
South China Morning Post
31-07-2025
- Science
- South China Morning Post
Explainer: why the huge 8.8 Russian earthquake caused little tsunami damage
One of the largest earthquakes ever recorded – a magnitude 8.8 monster – hit the eastern coast of Russia on Wednesday. Despite its remote location, the sheer size of the megathrust earthquake signalled probable danger, including a potential tsunami that would affect a significant part of the world. Tsunami alerts immediately went out, covering millions of people in Japan, the United States (US) and across the Pacific Ocean, reaching as far away as Hawaii, Chile and Ecuador. But for all its fury, the quake ended up not being a catastrophe. An official at a press conference in Tokyo on July 30, after the Japan Meteorological Agency issued a tsunami warning. Photo: Kyodo Best-case quake scenario Dangerous waves that rose more than 10 feet (3 metres) never materialised outside Russia. 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, harbourmaster for the Crescent City Harbour in California, US, a place that saw deadly tsunamis in 1964 after the magnitude 9.2–9.3 Alaska megathrust earthquake and in 2011 after a 9.0–9.1 undersea megathrust earthquake hit Tōhoku, Japan. Those events represent worst-case scenarios. Wednesday's represents a best-case scenario. 'With tsunamis, location and directionality are everything,' said Nathan Wood, a tsunami scientist with the US Geological Survey (USGS). 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. It is the largest since 2011, when a magnitude 9.1 tremor and subsequent tsunami struck off the coast of Japan and killed more than 15,000 people. Wednesday's Kamchatka earthquake is considered a megathrust, a characteristic shared by many of the planet's largest recorded quakes. Police officers search for information about missing persons after the 2011 earthquake and tsunami disaster in Namie-town, Fukushima prefecture, Japan. Photo: Kyodo via Reuters How did a megathrust earthquake cause such little damage? The area near the epicentre, 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 modelling 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 affected 'the local community that was right next to the source [earthquake] where it happened,' Wood said. Aerial view of Trujillo, Peru on July 30. Peru closed 65 of its 121 Pacific ports after a tsunami alert was issued following a massive 8.8-magnitude earthquake off the east coast of Russia. Photo: AFP '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 there wasn't really a whole lot in its way. By the time it got to the West Coast, like California, Oregon, a lot of the energy had been dissipated.' Russia saw tsunami waves as high as 16 feet (nearly 5 metres), according to news wire reports, but tsunami heights maxed out at 4 feet (1.2 metres) in Crescent City. The totals were even smaller in Southern California. The highest wave in the US was 5.7 feet in Kahului, Hawaii, on Maui. Dave Snider, the tsunami warning coordinator at the National Tsunami Warning Centre 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.' A view of a resort damaged by tsunami waves in the tourist beach destination of Khao Lak, Phang Nga province, southern Thailand, in December 2004. Photo: EPA-EFE A crisis averted Awareness of tsunami alerts has improved over the years, in large part thanks to deep ocean pressure sensors. 'There were several, fortunately, in operation right off the Kamchatka subduction zone,' said Eric Geist, research geophysicist for the USGS. One of the tragedies of the 2004 Indian Ocean disaster, a 9.3 undersea megathrust earthquake and subsequent tsunami, was a lack of warning. Waves rose up to 100 feet (30 metres), devastating communities and killing an estimated 227,898 people in 14 countries. Places hit very badly included Aceh in Indonesia, Sri Lanka, Tamil Nadu in southern India and Khao Lak in Thailand. It remains the deadliest tsunami in recorded history.
Yahoo
31-07-2025
- Climate
- Yahoo
A tiny city nicknamed a ‘tsunami magnet' saw the highest waves in continental US after the earthquake
A small Californian coastal city, notorious for its history of tsunamis, including one that claimed 11 lives over six decades ago, experienced minimal disruption on Wednesday, as residents quickly resumed their routines under clear skies. Crescent City, often dubbed a "tsunami magnet," recorded waves of up to 1.22 metres (4 feet) early on Wednesday. These were the highest observed anywhere in the continental United States following an 8.8-magnitude earthquake centred off Russia's Far East hours earlier. Crucially, these were significantly smaller than the devastating 6.40-metre (21-foot) waves that struck in 1964. This time, the city of 6,600 reported no injuries and no significant flooding, with its downtown area reopening later that morning. While a dock at the city's harbour sustained damage, officials swiftly issued warnings for the public to avoid beaches and waterways. 'A lot of people who aren't from here did evacuate. But they ended up coming right back because nothing happened,' said Rose Renee, who works at Oceanfront Lodge that looks out at the famed Battery Point Lighthouse. A surge of water lifted the dock off its pilings around 2:40 a.m., eventually submerging it, Harbormaster Mike Rademaker said at a news briefing. The dock was engineered to disrupt the waves' force before they reach the inner harbor and appears to have functioned as intended, he said. Crescent City is highly susceptible to tsunamis because of an underwater ridge, just offshore, known as the Mendocino Fracture Zone. The ridge funnels tsunamis into deeper water where they pick up speed before they hit the town. Forty-one tsunamis have been observed or recorded since the first tide gauge was installed in Crescent City in 1933. The oral history of local native peoples, geologic evidence and the written records of people elsewhere in the Pacific Rim suggest that tsunamis have battered this shoreline for centuries, according to city records. The 1964 event, considered the worst tsunami disaster recorded in the United States, began with a 9.2 magnitude earthquake in Alaska, according to the Crescent City website. Three small waves caused little damage, but then a big wave — nearly 21 feet (6.40 meters) — devastated 29 city blocks. The quake caused 15 deaths, and the ensuing tsunami caused 124 deaths: 106 in Alaska, 13 in California and 5 in Oregon, according to the National Oceanic and Atmospheric Administration's National Centers for Environmental Information. Crescent City rebuilt downtown, and today a walking tour highlights high-water marks posted on surviving buildings, objects pushed by waves and memorials to those who died. A tsunami caused by the March 2011 earthquake in Japan killed one person in Crescent City and damaged the harbor. Max Blair, a volunteer at the Del Norte Historical Society, which manages the town's museum and historic lighthouse, said locals have tsunami drills at least once a year. When there is danger of one, cellphone notifications go out and the tsunami sirens in the town sound warnings. Resident then turn to KCRE radio for information, Blair said. If ordered to evacuate, people move to higher ground, normally the town's Walmart about 2 miles (3.22 kilometers) from the shore. 'We evacuate if it's forecast to be a big wave. But the first wave was coming in at low tide and it was only a couple feet, so we just have to stay away from the beach,' Blair said. The city's website warns that a tsunami could happen anytime. Since most of downtown is in the tsunami run-up zone, if there were a near-shore earthquake, people would only have minutes to reach safety. Thirty-two tsunamis have been observed in the city since 1933, including five that caused damage. It is still not safe to head to the beach The greatest impact from the tsunami event along the coast Wednesday morning was around Crescent City with strong tidal swings, including up to 4-foot waves, according to James White, a meteorologist at the National Weather Service's Eureka office. Officials stressed that conditions may be improving, but it wasn't yet safe to head to the beach on Wednesday. There were still dramatic tide fluctuations that must carry high currents, the city manager said. 'It seems like whenever we have these events, it's also time that we lose someone just because they're in the wrong place and they get caught off-guard, and then they're swept out,' Weir said.
The Independent
31-07-2025
- Climate
- The Independent
A tiny city nicknamed a ‘tsunami magnet' saw the highest waves in continental US after the earthquake
A small Californian coastal city, notorious for its history of tsunamis, including one that claimed 11 lives over six decades ago, experienced minimal disruption on Wednesday, as residents quickly resumed their routines under clear skies. Crescent City, often dubbed a "tsunami magnet," recorded waves of up to 1.22 metres (4 feet) early on Wednesday. These were the highest observed anywhere in the continental United States following an 8.8-magnitude earthquake centred off Russia's Far East hours earlier. Crucially, these were significantly smaller than the devastating 6.40-metre (21-foot) waves that struck in 1964. This time, the city of 6,600 reported no injuries and no significant flooding, with its downtown area reopening later that morning. While a dock at the city's harbour sustained damage, officials swiftly issued warnings for the public to avoid beaches and waterways. 'A lot of people who aren't from here did evacuate. But they ended up coming right back because nothing happened,' said Rose Renee, who works at Oceanfront Lodge that looks out at the famed Battery Point Lighthouse. A surge of water lifted the dock off its pilings around 2:40 a.m., eventually submerging it, Harbormaster Mike Rademaker said at a news briefing. The dock was engineered to disrupt the waves' force before they reach the inner harbor and appears to have functioned as intended, he said. Crescent City is highly susceptible to tsunamis because of an underwater ridge, just offshore, known as the Mendocino Fracture Zone. The ridge funnels tsunamis into deeper water where they pick up speed before they hit the town. Forty-one tsunamis have been observed or recorded since the first tide gauge was installed in Crescent City in 1933. The oral history of local native peoples, geologic evidence and the written records of people elsewhere in the Pacific Rim suggest that tsunamis have battered this shoreline for centuries, according to city records. The 1964 event, considered the worst tsunami disaster recorded in the United States, began with a 9.2 magnitude earthquake in Alaska, according to the Crescent City website. Three small waves caused little damage, but then a big wave — nearly 21 feet (6.40 meters) — devastated 29 city blocks. The quake caused 15 deaths, and the ensuing tsunami caused 124 deaths: 106 in Alaska, 13 in California and 5 in Oregon, according to the National Oceanic and Atmospheric Administration's National Centers for Environmental Information. Crescent City rebuilt downtown, and today a walking tour highlights high-water marks posted on surviving buildings, objects pushed by waves and memorials to those who died. A tsunami caused by the March 2011 earthquake in Japan killed one person in Crescent City and damaged the harbor. Max Blair, a volunteer at the Del Norte Historical Society, which manages the town's museum and historic lighthouse, said locals have tsunami drills at least once a year. When there is danger of one, cellphone notifications go out and the tsunami sirens in the town sound warnings. Resident then turn to KCRE radio for information, Blair said. If ordered to evacuate, people move to higher ground, normally the town's Walmart about 2 miles (3.22 kilometers) from the shore. 'We evacuate if it's forecast to be a big wave. But the first wave was coming in at low tide and it was only a couple feet, so we just have to stay away from the beach,' Blair said. The city's website warns that a tsunami could happen anytime. Since most of downtown is in the tsunami run-up zone, if there were a near-shore earthquake, people would only have minutes to reach safety. Thirty-two tsunamis have been observed in the city since 1933, including five that caused damage. It is still not safe to head to the beach The greatest impact from the tsunami event along the coast Wednesday morning was around Crescent City with strong tidal swings, including up to 4-foot waves, according to James White, a meteorologist at the National Weather Service's Eureka office. Officials stressed that conditions may be improving, but it wasn't yet safe to head to the beach on Wednesday. There were still dramatic tide fluctuations that must carry high currents, the city manager said. 'It seems like whenever we have these events, it's also time that we lose someone just because they're in the wrong place and they get caught off-guard, and then they're swept out,' Weir said.
Yahoo
30-07-2025
- Science
- Yahoo
Why one of the biggest earthquakes ever recorded caused so little damage
It was one of the largest earthquakes ever recorded, a magnitude 8.8 monster off the eastern coast of Russia. 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
