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NBC News
31-07-2025
- Climate
- NBC News
Minimal U.S. effects from tsunami don't mean the forecast was inaccurate
The magnitude-8.8 earthquake off the coast of Russia's Kamchatka peninsula sent a wave of water racing at the speed of a jetliner toward Hawaii, California and Washington state, spurring warnings and alarm overnight on Wednesday. But when the tsunami waves arrived, they didn't cause devastation or deaths in the U.S. and the inundation might not have appeared threatening in some locations where warnings were issued. That doesn't mean the tsunami was a "bust," that it was poorly forecast or that it didn't pose a risk, earthquake and tsunami researchers said. 'You start to hear tsunami warning and everyone immediately thinks of the last Hollywood movie they saw and then it comes in at 3 feet and people are like, 'What's that?'' said Harold Tobin, the director of the Pacific Northwest Seismic Network and a professor at the University of Washington. 'We should count it as a win that a tsunami occurred, we got a warning and it wasn't the worst-case scenario.' Here's what to know. How strong was the Kamchatka earthquake? And why did it change so much? The initial reports of the Kamchatka earthquake from the United States Geological Survey pegged it as a 8.0-magnitude. Later, it was upgraded to an 8.8 magnitude quake. 'That is not uncommon for very, very large earthquakes in those initial minutes,' Tobin said. 'Our standard algorithms for determining the size of an earthquake quickly saturate. It's like turning up an amp and getting a lot of distortion." One of the first signs the earthquake was stronger than the initial seismic reports was an initial measurement from a buoy about 275 miles southeast of the Kamchatka peninsula. The buoy, which is part of the National Oceanographic and Atmospheric Administration's DART (Deep-ocean Assessment and Reporting of Tsunamis) system, is connected to a seafloor pressure sensor about 4 miles below the surface. The sensor registered a 90-centimeter wave, which is eye-popping to tsunami researchers. 'That's the second-largest recording we ever saw in the tsunami world,' said Vasily Titov, a senior tsunami modeler at NOAA's Pacific Marine Environmental Laboratory, adding that it indicated there was 'a catastrophic tsunami propagating in the ocean.' Titov said the only higher reading was from the 2011 Tōhoku earthquake and tsunami, which caused nearly 16,000 deaths in Japan. Seismic models later confirmed that Wednesday's earthquake was a magnitude-8.8, which means it released nearly 16 times as much energy as a magnitude-8.0 earthquake, according to a USGS calculation tool. Tōhoku was much bigger. Tobin estimated that earthquake released 2-3 times as much energy as was observed in Kamchatka. Titov said the tsunami in Japan was also about three times larger. Additionally, Tobin said the Tōhoku earthquake 'produced an anomalously large seafloor displacement,' lurching and moving more water than expected, even for an earthquake of its magnitude. At Kamchatka, 'it's likely that there was less seafloor displacement than could have happened in a worst case or more dire scenario for a magnitude 8.8,' Tobin said, though more research will be needed to confirm that theory. How did researchers make a forecast? How good was the forecast? In two hours' time, researchers produced a tsunami forecast for 'pretty much the whole Pacific and for warning points along the U.S. coastlines,' Titov said, with predictions of water levels at coastal tide gauges and also for flood inundation. The tsunami took about eight hours to reach Hawaii and 12 hours to reach the California coast. Titov, who helped build the models used by forecasters who issue warnings from the National Tsunami Warning Centers in Hawaii and Alaska, said the models rely on seismic data and the network of nearly 80 DART buoys in place along the Pacific Rim, which sense pressure changes. The U.S. owns and operates about half of the DART buoys. Titov said the models indicated that north shore areas of Hawaii would receive tsunami waves of about two meters or less. 'Hilo was predicted at about still two meters [6.5 feet] and it materialized at about 150 centimeters,' or 1.5 meters [5 feet], Titov said. 'It's exactly how we want it — a little bit on the conservative side.' The same trend played out in parts of California, Titov said. It will take some time to assess how well the models predicted inundation because reports are still coming in about the extent of flooding. 'We know that the flooding occurred at Hawaii. We don't know exactly the extent, but from the reports that I saw on TV, it looks like exactly what we predicted,' Titov said. Why were people in Hawaii evacuated for a five-foot wave? Yong Wei, a tsunami modeler and senior research scientist at the University of Washington and the NOAA Center for Tsunami Research, said a 1.5 meter [5 foot] tsunami wave can be very dangerous, particularly in shallow waters off Hawaii. Tsunami waves contain far more energy than wind waves, which are far shorter in wavelength, period (time between waves) and slower in speed. Wei said tsunami waves of the size that struck Hawaii can surge inland 'tens of meters,' produce dangerous currents and cause damage to boats and other moveable objects. 'People die. If they stay there and they don't get any warning, two meters can definitely kill people,' Wei said. 'If you're on the beach, strong currents can definitely pull you out into the ocean and people will get drowned.' Tobin said the initial warnings were conservative, but appropriate, in his view. 'I don't want people to think, oh, we had a warning and nothing much happened and poo poo it — 'I can ignore it,'' Tobin said. 'Warnings by nature have to err a bit on the side of caution.' Was this a historic event? No. The Kamchatka peninsula has a long history of earthquakes. 'This was an area that was ready for another earthquake and there had been a lot of earthquakes in that region over the last few weeks,' said Breanyn MacInnes, a professor in the Department of Geological Sciences at Central Washington University, which indicates increased risk. In 1952, before scientists had a strong understanding of plate tectonics, a 9.0-magnitude earthquake struck offshore of the Kamchatka peninsula in much the same region, sending a tsunami into the town of Severo-Kurilsk. 'People in Russia were not really prepared for it. It was very big earthquake, a big tsunami and they were caught off guard,' MacInnes said. MacInnes said the tsunami produced was between 30 and 60 feet in height in southern parts of the peninsula. 'Thousands of people were killed and basically the town was destroyed,' said Joanne Bourgeois, an emeritus professor of sedimentology at the University of Washington, who has been studying the region's earthquake history for about three decades. How would the tsunami warning system perform if the earthquake struck closer to home? The Kamchatka tsunami is a megathrust earthquake produced along large subduction zone fault, when one tectonic plate is forced beneath another. The U.S. west coast features a similar fault, called the Cascadia subduction zone, which runs offshore along the U.S. West Coast from Northern California to northern Vancouver Island. 'This is kind of a mirror image across the Pacific,' Tobin said. 'An 8.8 at a relatively shallow depth in Cascadia is definitely in the realm of scenarios. We could have a similar event here.' In fact, Cascadia has the potential to produce much larger quakes, Tobin said. Modeling suggests Cascadia could produce tsunami waves as tall as 100 feet. Subduction zone earthquakes typically produce tsunamis that reach shore in about 30 minutes to an hour, Titov said, which would strain forecasters' capabilities to predict tsunami effects precisely along the U.S. west coast before inundation happened. Titov said more seafloor sensors, more computer processing and innovation with artificial intelligence algorithms are needed to speed forecasting. Tobin said the successful tsunami warning on Tuesday should spur investment in seafloor sensors and seismic monitoring stations offshore along the subduction zone. 'This shows the value and importance of NOAA and the USGS [U.S. Geological Survey] in these times where some of these government agencies have come into question,' Tobin said. 'We wouldn't have had a tsunami warning if it weren't for NOAA and the next one could be a closer event. They showed their value.'
USA Today
30-07-2025
- Climate
- USA Today
What makes coastal California's Crescent City so vulnerable to tsunamis?
Crescent City, California, residents are breathing a sigh of relief after its latest tsunami warning was downgraded to an advisory. Crescent City, a redwood-tree lined coastal California community, is known as the tsunami capital of the country. The city has experienced more than three-dozen tsunamis in the last century. Once again, tsunami waves ‒ luckily modest this time ‒ reached the town, peaking as high as 4 feet near city shores before dawn on July 30, according to the National Weather Service. The waves came just hours after an 8.8-magnitude earthquake, one of the strongest tremblors in recorded history, struck off Russia's east coast, prompting tsunami waves in Hawaii and along the West Coast. "It was a long night for all of us. We were fortunate this time," Crescent City Manager Eric Weir said during a morning briefing on July 30. "There was significant tsunami surges. We're still dealing with those now, but it did stay within the banks." The July 29 tsunami warning was initially expected to last as long as 30 hours in Crescent City, according to the National Oceanic and Atmospheric Administration. Weir said the waves caused significant damage to a harbor dock as it lifted decking off the pilings, but the rest of the city was spared. "Downtown is at a high enough elevation that it is open," Weir said, about an hour before the tsunami warning was downgraded to an "advisory" for Crescent City, one of the last West Coast communities considered still at risk. City officials still advised locals to stay away from the harbor, beaches and waterways due to continued wave activity. "Conditions have started to improve," city officials said in a Facebook post. "But the ocean is still angry." Coastal calm: Tsunami evacuation orders lifted in Hawaii, threat to West Coast eases Crescent City's deadly tsunami history What makes Crescent City, a town of about 6,700 residents located about 25 miles south of the Oregon border, so tsunami-prone? Crescent City is vulnerable because it is located near the southern end of the Cascadia Subduction Zone, a major fault line capable of producing dangerous tsunamis and intense earthquakes, according to the Pacific Northwest Seismic Network. Several published studies also indicate that a Cascadia Subduction Zone tsunami can cause severe damage and inland flooding. In 2011, the earthquake in Japan spurred waves of more than 8 feet, destroying Crescent City's harbor. "The water went out to a low tide, but each wave was coming back in and it was getting higher and higher," Max Blair, 79, a volunteer at the Del Norte Historical Society located near downtown Crescent City, recalled to USA TODAY on July 30. "The harbor was a whole different story." One man died during the incident as the harbor docks were smashed and dozens of boats sank, causing an estimated $50 million in damage. The harbor was eventually rebuilt as the first "tsunami resistant port" on the West Coast. Another deadly tsunami struck Crescent City in 1964, triggered by a massive earthquake in Alaska, killing 11 people and injuring 35 others. The tsunami destroyed nearly 300 buildings and homes, causing between $11 million and $16 million in damages. The incident is considered one of the most devastating tsunamis in U.S. history. "I've heard and read about it," said Blair who's lived in Crescent City for more than 30 years. "I hope we never get to experience anything like that one."
Scientific American
09-07-2025
- Science
- Scientific American
Japan Wires the Ocean with an Earthquake-Sensing ‘Nervous System'
If the ocean floor had a nervous system, it might look something like this: thousands of miles of fiber-optic cables connected to sensors set atop the fault lines where Japan's earthquakes begin. Completed in June, this system aims to stave off devastation like that of 2011—when a relentless six-minute-long temblor was followed by a 130-foot tsunami that reached speeds of 435 miles per hour and pounded cities into rubble. Delayed alerts gave some communities less than 10 minutes to evacuate and only warned of much smaller waves, based on inaccurate earthquake readings. Nearly 20,000 people died, with thousands more injured or missing. Reactor meltdowns at the flooded Fukushima Daiichi nuclear power plant irradiated the surrounding land and spilled radioactive water into the ocean. The undersea, magnitude 9.0 'megathrust' earthquake—the worst in Japan's recorded history—began in the Pacific seafloor 45 miles off the country's eastern coast. Land-based sensors detected its first shock waves but couldn't immediately provide clear readings of its magnitude or that of the tsunami it created. Mere months later, Japan began expanding its earthquake-detection system to cover the ocean floor. With the system's completion last month, Japan has become the first country to achieve direct, real-time monitoring of entire subduction zones—adding minutes and seconds to evacuate people and brace crucial infrastructure for impact. But the advanced warning system is not the entire story, says seismologist Harold Tobin, director of the Pacific Northwest Seismic Network. 'By wiring up the offshore fault zone, we're constantly able to listen to it,' he says. 'That means we can detect all sorts of subtle signals that tell us how faults work, such as the storage of stress and how it starts to be released at the beginning of an earthquake.' 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. Japan Builds Its Ocean-Floor 'Nervous System' Within months of the 2011 earthquake, the Japanese government began to build S-net (Seafloor Observation Network for Earthquakes and Tsunamis). S-net wired the nation's earthquake-detection network to the Japan Trench, the seismologically active offshore region where the 2011 earthquake began. Roughly 3,540 miles of cable now zigzag across 116,000 square miles of ocean to connect 150 observatories on the ocean floor. Each contains 14 distinct sensing channels, including seismometers and accelerometers, as well as pressure gauges to measure waves passing overhead. This network—the first part of the larger network that was completed in June 2025—was finished in 2017. When a magnitude 6.0 quake struck the following year, alerts reached the cities before the first jolt hit—a full 20 seconds before the nearest land seismometer rang its alarm—allowing precious time to slow bullet trains and broadcast warnings. A much smaller seafloor network, the DONET (Dense Oceanfloor Network System for Earthquakes and Tsunamis) had been started in 2006 along a section of the Nankai Trough, another geologically active zone, where the Philippine Sea plate pushes beneath southwestern Japan. This zone had been considered Japan's most urgent seismic threat. The last pair of magnitude 8.0-plus ruptures had occurred there in 1944 and 1946. And because historical intervals for major earthquakes in that area occur at an average of 100 to 200 years, stress between the plates was assumed to be nearing its breaking point. The Nankai megathrust zone lies only 40 to 60 miles off the densely populated hubs of Osaka and Nagoya and the Tōkai industrial belt—and the area's trench geometry happens to aim tsunamis straight at the shore. Disaster plans project hundreds of thousands of casualties and economic losses of more than $1 trillion if warnings arrive only after land sensors are alerted. In 2013 DONET was expanded to include more than 460 miles of cables. And in 2019 the now recently completed N-net (Nankai Trough Seafloor Observation Network for Earthquakes and Tsunamis) was begun; it presently covers the rest of the Nankai megathrust zone. Connected by more than 1,000 miles of cable, N-net's 36 observatories complete Japan's larger earthquake-detection system. With the final N-net link set up this June, the complete system increases warning times by 20 seconds for earthquakes and a full 20 minutes for tsunamis—enough time to divert incoming flights and close sea gates in busy ports. And the project could provide seismologists with a treasure trove of useful new data. Of particular interest are slow-slip events, in which faults gradually release without earthquakes. 'If you wind the clock back 20 years, we basically thought faults were either locked and not moving at all or were having an earthquake and moving very, very fast,' Tobin explains. But slow-slip events reveal a third mode in which faults move faster than the steady plate tectonic rate but much slower than an earthquake. Whereas slow-slip events generally aren't present before small earthquakes, they often occur in the days before major ones—perhaps detaching 'enough of the fault zone that it prepares the system for a big earthquake,' Tobin says. 'That might end up being something we can use as an earthquake-precursor-detection system.' He's quick to point out, however, that not all slow-slip events are followed by earthquakes. N-net technicians will spend the coming months calibrating instruments and folding their feeds into a single monitoring backbone that includes Japan's approximately 6,000 land-based sensors. But the hardest part is done: installing armored fiber-optic cables and observatories along the abyssal plain from ships and 'plowing' shallow seabed areas to bury cables and protect them from anchors and fishing gear. Underwater robots helped out in deeper waters and will now service the observatories and replace parts. From Nuclear Bomb Detectors to Tsunami Alarms The completion of Japan's network coincides with that of another tsunami-detection program at Cardiff University in Wales. GREAT (Global Real-Time Early Assessment of Tsunamis) came online in June and streams data from four of the 11 hydroacoustic ocean stations created for the Comprehensive Nuclear-Test-Ban Treaty Organization. Built to listen for clandestine nuclear bomb blasts, the globe-spanning system detects low-frequency acoustic-gravity waves. These pressure pulses sprint through seawater at roughly 3,355 miles per hour—more than 10 times faster than a tsunami's leading edge. Researchers at Cardiff University use machine-learning algorithms to interpret the hydrophone signals. Within seconds, the system estimates earthquake magnitude, fault slip type, and tsunami potential and sends out alerts, though researchers estimate that a total of two dozen hydrophone sites would be required to make coverage global. Cascadia's Silent Megathrust: A Massive Quake Waiting Unseen Even as such detection systems expand, however, one of the planet's most vulnerable faults remains among the least monitored: the Cascadia megathrust fault, which runs along the coast of the Pacific Northwest from Vancouver Island to northern California. Unlike Japan's faults, this one does not produce many small earthquakes—which initially led seismologists to believe it posed little risk. But recent research has shown it is prone to rare but massive quakes. In stark contrast to Japan, the Cascadia megathrust fault has only a single cable with three seismometers, though funding was recently secured to replace one of the seismometers and to add three more. (Canada also has a small cable system in place.) 'We have just the paltriest beginnings of what they have in Japan,' Tobin says. Early detection of a massive earthquake could give tens of millions of people along the Pacific Northwest coast more time to prepare, as might detection of slow-slip events in the fault. 'We actually understand really well now that it's just storing up the stress toward a very big—potentially magnitude-9-scale—earthquake, every bit as big as 2011, with the same tsunami hazard,' he says. 'It's pretty inevitable.'
Yahoo
08-07-2025
- Science
- Yahoo
Earthquake swarm strikes Mt Rainier in Washington state
Mount Rainier, the active volcano towering above southwestern Washington state, started rumbling — very lightly — on Tuesday. A swarm of small earthquakes was detected under the mountain triggering focused monitoring from officials. But researchers have determined there is no current threat of an eruption. The earthquake swarm started just before 1:30 a.m. local time, according to the U.S. Geological Survey's Cascades Volcano Observatory and the Pacific Northwest Seismic Network. Since the swarm began, hundreds of tiny earthquakes have occurred near the volcano's summit, with the largest's magnitude detected at 1.7. The earthquakes' origins have been recorded between 1.2 and 3.7 miles beneath the summit of the mountain. None have been felt on the surface, according to KPTV. Since Mount Rainier is an active volcano officials said the seismic activity wasn't abnormal and stressed there was no cause for alarm. The volcano's alert level has remained at normal, and its color code at green, which indicates typical activity. 'Mount Rainier typically sees about nine earthquakes per month,' the agencies said in a statement after the swarms were detected. 'Swarms like this happen once or twice a year, though this one is larger than usual.' The last significant earthquake at Mount Rainier occurred in 2009, and rumbled on for three days. More than 1,000 seismic events were recorded with the most substantial registering a 2.3 magnitude. Previous swarms have been attributed to fluids circulating under the mountain, and interacting with faults deep underground, and not volcanic activity. According to the U.S. Geological Survey, the last eruptive period for Mount Rainier occurred around 1,000 years ago, but even in that incident there were no lava flows. The last major destructive eruption to hit Washington state was not at Mount Rainier, but at Mount St Helens — approximately 50 miles away, but part of the same mountain range — in 1980. That eruption killed 57 people. The snowcapped Mount Rainier is located in Mount Rainier National Park, approximately 59 miles southeast of Seattle. The mountain is the highest peak in Washington state and on clear days is visible from Seattle.
The Independent
08-07-2025
- Science
- The Independent
Earthquake swarm strikes Mt Rainier in Washington state
Mount Rainier, the active volcano towering above southwestern Washington state, started rumbling — very lightly — on Tuesday. A swarm of small earthquakes was detected under the mountain triggering focused monitoring from officials. But researchers have determined there is no current threat of an eruption. The earthquake swarm started just before 1:30 a.m. local time, according to the U.S. Geological Survey's Cascades Volcano Observatory and the Pacific Northwest Seismic Network. Since the swarm began, hundreds of tiny earthquakes have occurred near the volcano's summit, with the largest's magnitude detected at 1.7. The earthquakes' origins have been recorded between 1.2 and 3.7 miles beneath the summit of the mountain. None have been felt on the surface, according to KPTV. Since Mount Rainier is an active volcano officials said the seismic activity wasn't abnormal and stressed there was no cause for alarm. The volcano's alert level has remained at normal, and its color code at green, which indicates typical activity. 'Mount Rainier typically sees about nine earthquakes per month,' the agencies said in a statement after the swarms were detected. 'Swarms like this happen once or twice a year, though this one is larger than usual.' The last significant earthquake at Mount Rainier occurred in 2009, and rumbled on for three days. More than 1,000 seismic events were recorded with the most substantial registering a 2.3 magnitude. Previous swarms have been attributed to fluids circulating under the mountain, and interacting with faults deep underground, and not volcanic activity. According to the U.S. Geological Survey, the last eruptive period for Mount Rainier occurred around 1,000 years ago, but even in that incident there were no lava flows. The last major destructive eruption to hit Washington state was not at Mount Rainier, but at Mount St Helens — approximately 50 miles away, but part of the same mountain range — in 1980. That eruption killed 57 people. The snowcapped Mount Rainier is located in Mount Rainier National Park, approximately 59 miles southeast of Seattle. The mountain is the highest peak in Washington state and on clear days is visible from Seattle.
