Latest news with #Deep-oceanAssessmentandReportingofTsunamis
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Business Standard
31-07-2025
- Science
- Business Standard
Here's why small tsunami waves still trigger mass evacuations worldwide
One of the largest earthquakes ever recorded — 8.8 magnitude tremor — struck off the coast of Russia's Kamchatka Peninsula on Wednesday, triggering tsunami warnings and evacuations across the Pacific. Although the quake's power was immense, the resulting tsunami waves are projected to be relatively moderate, raising questions and concerns around evacuation protocols and public safety, The Conversation reported. What is happening The epicentre of the earthquake was the sea near Kamchatka, a remote peninsula facing the Pacific Ocean. Russia reported waves up to 4 metres high. Other regions, including Japan, China, Hawaii, and even South American countries like Ecuador and Chile, are projected to see waves ranging from 30 cm to 3 metres. What are scientists saying? The context Tsunami waves, even when small, can carry dangerous force and escalate rapidly. Experts said it is safer to evacuate early than risk delays. 'Too early is far better than too late,' one expert said, as quoted by The Conversation. Uncertainty is built into early warnings, which often rely on limited quake data before tsunami measurements become available. Behavioural scientists have found that evacuation compliance increases when people believe the threat is real, trust authorities, and see others around them taking action. However, when people act outside official guidance, known as 'shadow evacuation', they can clog roads, overload shelters, and create unnecessary risk. The bigger picture Wealthy nations like Japan, which frequently face tsunamis, have invested in early warning systems, drills, vertical shelters, and coastal sirens. In contrast, developing nations often lack such infrastructure, leading to higher casualties during disasters. Following a costly false alarm in Hawaii in 1986, the US developed the DART (Deep-ocean Assessment and Reporting of Tsunamis) system, which uses deep-sea buoys to monitor real-time ocean pressure. This has helped reduce false alarms and improve public trust in alerts. Lessons from history The 2004 Indian Ocean tsunami, triggered by a 9.1 magnitude quake, killed over 227,000 people in Indonesia, India, Sri Lanka, and Thailand — areas with little warning infrastructure. In contrast, Japan's 2011 tsunami, despite being caused by an even stronger quake, saw fewer deaths thanks to stronger preparedness and faster evacuations. In 2018, more than 4,000 people died in Sulawesi, Indonesia, after a 7.6 magnitude quake caused a tsunami. Public disbelief and poor communication hampered timely evacuation. What to do Tsunamis are rare but catastrophic. Authorities stress that when an evacuation order is issued, it must be taken seriously. Early, orderly action saves lives, far more than waiting until roads are flooded and panic has set in.
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.'
Yahoo
30-07-2025
- Climate
- Yahoo
What is a tsunami warning? What to know after huge earthquake.
An earthquake powerful enough to rank among the top 10 strongest earthquakes on record struck off the coast of Russia on July 29, triggering a series of tsunami warnings and watches. The earthquake measured an incredible magnitude of 8.8. For context, the Michigan Technological University says magnitude 8.0 or greater earthquakes can cause massive damage and destroy communities. The U.S. Tsunami Warning System ( will be updating its guidance as experts learn more about the threat, including maps showing what areas face what risks. In the minutes and hours after a major earthquake, tsunami assessments change as researchers track data from buoy and other interments. Latest updates: Live coverage of Tsunami risk after 8.8 earthquake off Russia Here's what each of the alert levels mean, according to the agency: Tsunami Warning: Take Action—Danger! A tsunami that may cause widespread flooding is expected or occurring. Dangerous coastal flooding and powerful currents are possible and may continue for several hours or days after initial arrival. Follow instructions from local officials. Evacuation is recommended. Move to high ground or inland (away from the water). Tsunami Advisory: Take Action—A tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas. Stay out of the water and away from beaches and waterways. Follow instructions from local officials. Tsunami Watch: Be Prepared—A distant earthquake has occurred. A tsunami is tuned for more information. Be prepared to take action if necessary. Tsunami Information Statement: Relax—An earthquake has occurred, but there is no threat or it was very far away and the threat has not been determined. In most cases, there is no threat of a destructive tsunami. People who live along the coast can check information from their local emergency management offices to get information for their region and risks. Map shows Tsunami warnings, watches How does NOAA track tsunamis? A real-time tsunami monitoring system created by the Pacific Marine Environmental Laboratory in Washington placed buoys at strategic locations throughout the ocean that play a critical role in tsunami forecasting, according to the National Oceanic and Atmospheric Administration. The buoys are named DART, for Deep-ocean Assessment and Reporting of Tsunamis. When a tsunami event occurs, the first information available is the seismic information from the preceding earthquake, according to NOAA. As the tsunami wave moves across the ocean, it reaches the DART systems, which report sea level information measurements to the Tsunami Warning Centers. That buoy data is used to refine estimates of the tsunami source and to make the forecasts for watches, warnings and evacuations. The Pacific Marine Environmental Laboratory is working on a third generation of the buoy system, but the laboratory is one of those proposed to be closed under the budget NOAA has proposed for the coming year. Where does the Russian earthquake rank? If the 8.8 magnitude remains after a final review, the earthquake would be tied for the 6th most powerful with an earthquake in Chile on Feb. 27, 2010 and an earthquake near the coast of Ecuador on Jan. 31, 1906. The largest earthquake in history, the Validivian Earthquake, occurred on May 22, 1960 and measured at a magnitude of 9.5 off the coast of Chile. (This story has been updated to add new information.) Contributing: Dinah Voyles Pulver and Jeanine Santucci, USA TODAY This article originally appeared on USA TODAY: What is a tsunami warning? Watches and warnings explained.
Yahoo
30-07-2025
- Climate
- Yahoo
What is a tsunami warning? What to know after huge earthquake.
An earthquake powerful enough to rank among the top 10 strongest earthquakes on record struck off the coast of Russia on July 29, triggering a series of tsunami warnings and watches. The earthquake measured an incredible magnitude of 8.8. For context, the Michigan Technological University says magnitude 8.0 or greater earthquakes can cause massive damage and destroy communities. The U.S. Tsunami Warning System ( will be updating its guidance as experts learn more about the threat, including maps showing what areas face what risks. In the minutes and hours after a major earthquake, tsunami assessments change as researchers track data from buoy and other interments. Latest updates: Live coverage of Tsunami risk after 8.8 earthquake off Russia Here's what each of the alert levels mean, according to the agency: Tsunami Warning: Take Action—Danger! A tsunami that may cause widespread flooding is expected or occurring. Dangerous coastal flooding and powerful currents are possible and may continue for several hours or days after initial arrival. Follow instructions from local officials. Evacuation is recommended. Move to high ground or inland (away from the water). Tsunami Advisory: Take Action—A tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas. Stay out of the water and away from beaches and waterways. Follow instructions from local officials. Tsunami Watch: Be Prepared—A distant earthquake has occurred. A tsunami is tuned for more information. Be prepared to take action if necessary. Tsunami Information Statement: Relax—An earthquake has occurred, but there is no threat or it was very far away and the threat has not been determined. In most cases, there is no threat of a destructive tsunami. People who live along the coast can check information from their local emergency management offices to get information for their region and risks. Map shows Tsunami warnings, watches How does NOAA track tsunamis? A real-time tsunami monitoring system created by the Pacific Marine Environmental Laboratory in Washington placed buoys at strategic locations throughout the ocean that play a critical role in tsunami forecasting, according to the National Oceanic and Atmospheric Administration. The buoys are named DART, for Deep-ocean Assessment and Reporting of Tsunamis. When a tsunami event occurs, the first information available is the seismic information from the preceding earthquake, according to NOAA. As the tsunami wave moves across the ocean, it reaches the DART systems, which report sea level information measurements to the Tsunami Warning Centers. That buoy data is used to refine estimates of the tsunami source and to make the forecasts for watches, warnings and evacuations. The Pacific Marine Environmental Laboratory is working on a third generation of the buoy system, but the laboratory is one of those proposed to be closed under the budget NOAA has proposed for the coming year. Where does the Russian earthquake rank? If the 8.8 magnitude remains after a final review, the earthquake would be tied for the 6th most powerful with an earthquake in Chile on Feb. 27, 2010 and an earthquake near the coast of Ecuador on Jan. 31, 1906. The largest earthquake in history, the Validivian Earthquake, occurred on May 22, 1960 and measured at a magnitude of 9.5 off the coast of Chile. (This story has been updated to add new information.) Contributing: Dinah Voyles Pulver and Jeanine Santucci, USA TODAY This article originally appeared on USA TODAY: What is a tsunami warning? Watches and warnings explained.
Indian Express
17-07-2025
- Climate
- Indian Express
Tsunami advisory issued in Alaska after 7.3-magnitude earthquake rattles island
A 7.3 magnitude earthquake struck Alaska's southern coast near Sand Point on Wednesday, which triggered a tsunami warning by the National Oceanic and Atmospheric Administration, but was later downgraded to advisory level. The strong earthquake which was felt throughout the southern coast of Alaska had a magnitude of 7.3, according to the US Geological Survey. The earthquake occurred near Sand Point which is located northwest of Popof Island off the Alaska peninsula. The location is about 965 kilometres southwest of Anchorage, Alaska. According to the US Tsunami Center, the tsunami advisory issued after the 7.3 magnitude earthquake remains in effect from about 65 km south-west of Homer to Unimak Pass. The tsunami advisory was issued for South Alaska and the Alaska Peninsula to Kennedy Entrance and Unimak Pass, Alaska, on the Pacific Coast. The area affected by the advisory is densely populated, and the larger community in the area is Kodiak which is home to 5,200 people. Notable quake, preliminary info: M 7.3 – 87 km S of Sand Point, Alaska — USGS Earthquakes (@USGS_Quakes) July 16, 2025 In a statement to ABC News, Kodiak police said sirens were sounded in the city which means people need to move to higher ground. The police added that any impact in the area would be expected at about 2:40 pm (local time). Authorities said there haven't been any reports of damage due to the earthquake in Kodiak. Kodiak police urged residents to utilize emergency shelters in the local elementary and high schools if there's a need to evacuate from the inundation zone. Soon after data analysis from the Deep-ocean Assessment and Reporting of Tsunamis, the Washington Emergency Management said there was no danger for Washington state from the earthquake in Alaska. After the tsunami advisory was issued, a report in The Guardian stated the first waves are poised to hit the village of Sand Point, a community which houses close to 600 people on Popof Island.
