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Tag: Tsunami

  • Oregon hospital races to build a tsunami shelter as FEMA fights to cut its funding

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    ASTORIA, Ore. — Residents of this small coastal city in the Pacific Northwest know what to do when there’s a tsunami warning: Flee to higher ground.

    For those in or near Columbia Memorial, the city’s only hospital, there will soon be a different plan: Shelter in place. The hospital is building a new facility next door with an on-site tsunami shelter — an elevated refuge atop columns deeply anchored in the ground, where nearly 2,000 people can safely wait out a flood.

    Oregon needs more shelters like the one that Columbia Memorial is building, emergency managers say. Hospitals in the region are likely to incur serious damage, if not ruin, and could take more than three years to fully recover in the event of a major earthquake and tsunami, according to a state report.

    Columbia Memorial’s current facility is a single-story building, made of wood a half-century ago, that would likely collapse and sink into the ground or be swallowed by a landslide after a major earthquake or a tsunami, said Erik Thorsen, the hospital’s chief executive.

    “It is just not built to survive either one of those natural disaster events,” Thorsen said.

    At least 10 other hospitals along the Oregon coast are in danger as well. So Columbia Memorial leaders proposed building a hospital capable of withstanding an earthquake and landslide, with a tsunami shelter, instead of relocating the facility to higher ground. Residents and state officials supported the plans, and the federal government awarded a $14 million grant from the Federal Emergency Management Agency to help pay for the tsunami shelter.

    Columbia Memorial Hospital is a single-story, wood-frame building that would likely sustain significant damage in an earthquake or tsunami. The hospital was awarded a $14 million FEMA grant to help pay for an elevated tsunami shelter, but the Trump administration canceled the grant program in April.

    Hannah Norman/KFF Health News


    The project broke ground in October 2024. Within six months, the Trump administration had canceled the grant program, known as Building Resilient Infrastructure and Communities, or BRIC, calling it “yet another example of a wasteful and ineffective FEMA program … more concerned with political agendas than helping Americans affected by natural disasters.”

    Molly Wing, director of the expansion project, said losing the BRIC grant felt like “a punch to the gut.”

    “We really didn’t see that coming,” she said.

    This summer, Oregon and 19 other states sued to restore the FEMA grants. On Dec. 11, a judge ruled that the Trump administration had unlawfully ended the program without congressional approval.

    The administration did not immediately indicate it would appeal the decision, but Department of Homeland Security spokesperson Tricia McLaughlin said by email: “DHS has not terminated BRIC. Any suggestion to the contrary is a lie. The Biden Administration abandoned true mitigation and used BRIC as a green new deal slush fund. It’s unfortunate that an activist judge either didn’t understand that or didn’t care.” FEMA is a subdivision of DHS.

    Columbia Memorial was one of the few hospitals slated to receive grants from the BRIC program, which had announced more than $4.5 billion for nearly 2,000 building projects since 2022.

    Hospital leaders have decided to keep building — with uncertain funding — because they say waiting is too dangerous. With the Trump administration reversing course on BRIC, fewer communities will receive help from FEMA to reduce their disaster risk, even places where catastrophes are likely.

    More than three centuries have passed since a major earthquake caused the Pacific Northwest’s coastline to drop several feet and unleashed a tsunami that crashed onto the land in January 1700, according to scientists who study the evolution of the Oregon coast.

    The greatest danger is an underwater fault line known as the Cascadia Subduction Zone, which lies 70 to 100 miles off the coast, from Northern California to British Columbia.

    tsunami-hospital13.jpg

    Astoria, Oregon, is a city of 10,000 residents on a peninsula near the end of the Lewis & Clark National Historic Trail. It’s located on the southern shore of the Columbia River, near the Washington border. Picturesque forests and the river frame streets lined with gift shops, hotels, and seafood restaurants — almost entirely in an evacuation zone. 

    Hannah Norman/KFF Health News


    The Cascadia zone can produce a megathrust earthquake, with a magnitude of 9 or higher — the type capable of triggering a catastrophic tsunami — every 500 years, according to the U.S. Geological Survey. Scientists predict a 10% to 15% chance of such an earthquake along the fault zone in the next 50 years.

    “We can’t wait any longer,” Thorsen said. “The risk is high.”

    Building for the future

    The BRIC program started in 2020, during the first Trump administration, to provide communities and institutions with funding and technical assistance to fortify their structures against natural disasters.

    Joel Scata, a senior attorney with the environmental advocacy group Natural Resources Defense Council, said the program helped communities better prepare so they could reduce the cost of rebuilding after a flood, tornado, wildfire, or extreme weather event.

    To qualify for a grant, a hospital had to show that the project’s benefits were greater than the future danger and cost. In some cases, that benefit might not be readily apparent.

    “It prevents bad disasters from happening, and so you don’t necessarily see it in action,” Scata said.

    Scata noted that the Trump administration has also stopped awarding grants through FEMA’s Hazard Mitigation Grant Program, which predates BRIC.

    “There really is no money going out the door from the federal government to help communities reduce their disaster risk,” he said.

    A recent KFF Health News investigation using proprietary data from Fathom, a global leader in flood modeling, found that at least 170 U.S. hospitals are at risk of significant and potentially dangerous flooding from more intense and frequent storms. That count did not include Columbia Memorial, as Fathom’s data did not account for tsunamis. It models flooding from rivers, sea level rise, and extreme rainfall.

    In recent days, an atmospheric river — a narrow storm band carrying significant amounts of moisture — dumped more than 15 inches of rain on parts of Oregon and Washington, causing catastrophic flooding along rivers and the coast. In the Washington town of Sedro-Woolley, which sits along the Skagit River, the PeaceHealth United General Medical Center evacuated nonemergency patients.

    High winds battered Astoria, leaving the city with some minor landslides, according to news reports. But flooding on the road to the nearby beach town of Seaside made the drive nearly impassable.

    The Trump administration is leaning on states to take greater responsibility for recovering from natural disasters, Scata said, but most states are not financially prepared to do so.

    “The disasters are just going to keep on piling up,” he said, “and the federal government’s going to have to keep stepping in.”

    A hospital at risk

    Columbia Memorial is blocks from the southern shore of the Columbia River, near the Washington border, where the area’s natural hazards include earthquakes, tsunamis, landslides, and floods. A critical access hospital with 25 beds, it opened in 1977 — before state building codes addressed tsunami protections.

    Thorsen said the new facility and shelter would be a “model design” for other hospitals. Design plans show a five-level hospital built atop a foundation anchored to the bedrock and surrounded by concrete columns to shield it from tsunami debris.

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    Columbia Memorial Hospital’s expansion plans call for an outdoor staircase leading to a rooftop tsunami refuge capable of holding up to 1,900 people, and enough food, water, tents, and other supplies to sustain them for five days. 

    Columbia Memorial Hospital


    The shelter will be on the roof of the second floor, above the projected maximum tsunami inundation. It will be accessible via an outdoor staircase and interior staircases and elevators, with enough room for up to 1,900 people, plus food, water, tents, and other supplies to sustain them for five days.

    With most patient care provided on the second and third levels, generators on the fourth level, and utility lines underground, the hospital is expected to remain operational after a natural disaster.

    tsunami-hospital20.jpg

    Design plans for Columbia Memorial Hospital show a five-level building with a rooftop refuge designed to withstand an earthquake and keep people safe from a tsunami. Most patient services will be provided on the second and third levels, above the projected tsunami flood level.

    Columbia Memorial Hospital


    Thorsen said an earthquake and tsunami threaten not only vast flooding but also liquefaction, in which the ground loosens and causes structures above it to collapse. Deep foundations, thick slabs, and other structural supports are expected to protect the new hospital and tsunami structure against such failure.

    Through the years, hospital administrators and civic leaders in Astoria have sought other locations for Columbia Memorial. But relocation wasn’t economical. Columbia Memorial committed to invest in a new hospital and tsunami shelter to protect not only patients and staff but also nearby residents.

    “Your community should count on your hospital to be a safe haven in a natural disaster,” Thorsen said.


    Oregon Hospital Races to Build a Tsunami Shelter as FEMA Fights To Cut Its Funding by
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    Fighting to restore funds

    The estimated construction budget for Columbia Memorial’s expansion is $300 million, mostly financed through new debt from the hospital. The tsunami shelter is budgeted at about $20 million, for which FEMA’s BRIC program awarded nearly $14 million, with a $6 million matching grant from the state, which has maintained its support.

    The shelter and the building’s structural protections — featuring reinforced steel, deeper foundations, and thicker slabs — are integral to the design and cannot be removed without compromising the rest of the structure, said Michelle Checkis, the project architect.

    “We can’t pull the TVERS [tsunami vertical evacuation refuge structure] out without pulling the hospital back apart again,” she said. “It’s kind of like, if I was going to stack it up with Legos, I would have to take all those Legos apart and stack it up completely differently.”

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    Molly Wing is the director of Columbia Memorial Hospital’s expansion project, and Michelle Checkis is the architect of the new facility, which includes a rooftop tsunami shelter.

    Hannah Norman/KFF Health News


    Columbia Memorial has sought help from Oregon’s congressional delegation. In a letter to Department of Homeland Security Secretary Kristi Noem and former FEMA acting administrator David Richardson, the lawmakers demanded that the agencies restore the hospital’s grant.

    The hospital’s leadership is seeking other grants and philanthropic donations to make up for the loss. As a last resort, Thorsen said, the board will consider removing “nonessential features” from the building, though he added that there is little fat to trim from the project.

    The lawsuit brought by states in July alleged that FEMA lacks the authority to cancel the BRIC program or redirect its funding for other purposes.

    The states argued that canceling the program ran counter to Congress’ intent and undermined projects underway.

    In their response to the lawsuit, the Trump administration said repeatedly that the defendants “deny that the BRIC program has been terminated.”

    The lawsuit cites examples of projects at risk in each state due to FEMA’s termination of the grants. Oregon’s first example is Columbia Memorial’s tsunami shelter. “Neither the County nor the State can afford to resume the project without federal funding,” the lawsuit states.

    In response to questions about the impact of canceling the grant on Astoria and the surrounding community, DHS spokesperson Tricia McLaughlin said BRIC had “deviated from its statutory intent.”

    “BRIC was more focused on climate change initiatives like bicycle lanes, shaded bus stops, and planting trees, rather than disaster relief or mitigation,” McLaughlin said. DHS and FEMA provided no further comment about BRIC or the Astoria hospital.

    Preparing for a tsunami disaster

    Located near the end of the Lewis & Clark National Historic Trail, Astoria sits on a peninsula that juts into the Columbia River near the Pacific Ocean.

    Much of the city is not in the tsunami inundation area. But Astoria’s downtown commercial district — where gift shops, hotels, and seafood restaurants line the streets — is nearly all an evacuation zone.

    tsunami-hospital15.jpg

    Fish canning was once the primary industry in Astoria, Oregon, until the last cannery closed in the 1980s. 

    Hannah Norman/KFF Health News


    Two hospitals — Ocean Beach Health in nearby Washington, and Providence Seaside Hospital in Oregon — are about 20 miles from Columbia Memorial. Both are 25-bed hospitals, and neither is designed to withstand a tsunami.

    Ocean Beach Health regularly conducts drills for mass-casualty and natural disasters, said Brenda Sharkey, its chief nursing officer.

    “We focus our planning and investments on areas where we can make a real difference for our community before, during, and after an event — such as maintaining continuity of care, ensuring rapid triage, and coordinating with regional emergency partners,” Sharkey said in an email.

    Gary Walker, a spokesperson for Providence Seaside, said in a statement that the hospital has a “comprehensive emergency plan for earthquakes and tsunamis, including alternative sites and mobile resources.”

    Walker added that Providence Seaside has hired “a team of consultants and experts to conduct a conceptual resilience study” that would evaluate the hospital’s vulnerabilities and recommend ways to address them.

    Oregon’s emergency managers advise residents and visitors in coastal communities to immediately seek higher ground after a major earthquake — and not to rely on tsunami sirens, social media, or most technology.

    “There may not even be cellphone towers operating after an event like this,” said Jonathan Allan, a coastal geomorphologist with the Oregon Department of Geology and Mineral Industries. “The earthquake shaking, its intensity, and particularly the length of time in which the shaking persists, is the warning message.”

    The stronger the earthquake and the longer the shaking, he said, the more likely a tsunami will head to shore.

    A tsunami triggered by a Cascadia zone earthquake could strike land in less than 30 minutes, according to state estimates.

    Many of Oregon’s seaside communities are near high-enough ground to seek safety from a tsunami in a relatively short time, Allan said. But he estimated that, to save lives, Oregon would need about a dozen vertical tsunami evacuation shelters along the coast, including in seaside towns that attract tourists and where the nearest high ground is a mile or more away.

    Willis Van Dusen’s family has lived in Astoria since the mid-19th century. A former mayor of Astoria, Van Dusen stressed that tsunamis are not a hypothetical danger. He recalled seeing one in Seaside in 1964. The wave was only about 18 inches high, he said, but it flooded a road and destroyed a bridge and some homes. The memory has stayed with him.

    “It’s not like … ‘Oh, that’ll never happen,’” he said. “We have to be prepared for it.”

    KFF Health News correspondent Brett Kelman contributed to this report.

    KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF — the independent source for health policy research, polling, and journalism.

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  • Human remains found in Japan identified as girl missing since 2011 earthquake and tsunami

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    Human remains found in Japan have been identified as those of a six-year-old girl missing since the massive earthquake and tsunami of 2011, police said Friday.

    The disaster killed 15,900 people, with 2,520 people still listed as missing as of the end of February, according to the National Police Agency.

    Teeth and fragments of jaw were discovered in February 2023 in the northern region of Miyagi, a spokesman for the local police told AFP. 

    “After dental and DNA identification analyses, it was confirmed the remains belong to Natsuse Yamane, female, who was six years old at the time,” he said.

    Mitochondrial DNA analysis and an examination of proteins on the teeth confirmed the girl’s identity, the Japan Times reported, citing the Miyagi police. Experts at Tohoku University assisted with the analysis, Japan Today reported.

    The girl had been at her home in Yamada, a town around 60 miles away in Iwate Prefecture, when the tsunami swept her away, the police spokesman told AFP.

    She had been listed as missing ever since.

    The remains were found by construction workers sifting through material amassed in a clean-up of coastal areas, the Asahi Shimbun daily reported.

    The child’s family issued a statement of thanks.

    “We had long given up (on finding her remains), so when we were notified, it took us by surprise. We are very grateful,” Japan Today quoted the family as saying. 

    Fishing boats lie amongst tsunami devastation in the town of Yamada, Iwate prefecture on May 4, 2011 nearly two months after the 9.0 magnitude earthquake and subsequent tsunami hit Japan. 

    TOSHIFUMI KITAMURA/AFP via Getty Images


    The last time remains were identified in the three prefectures hardest hit by the disaster — Iwate, Miyagi, and Fukushima — was in August 2023, the Asahi said.  The unidentified remains of six other people are in the custody of authorities in the prefecture, Japan Today reported.

    The 9.0-magnitude earthquake in March 2011 also sent three reactors into meltdown at the Fukushima nuclear plant in this century’s biggest atomic disaster.

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  • Multiple earthquakes slam Russian coastline

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    Minor earthquakes have continued rattling the Kamchatka region of Russia in the aftermath of a massive 7.8 magnitude temblor that struck the area on Thursday, with aftershocks from 4.5 to 5.5 magnitude throughout Friday.

    Why It Matters

    Three moderate earthquakes struck off the coast of Russia’s Kamchatka Peninsula early Monday, shaking one of the world’s most geologically volatile regions. Kamchatka borders the Pacific Ring of Fire, and the region has endured a number of recent quakes just two months after getting slammed by one packing an 8.8 magnitude.

    The activity culminated in Thursday’s quake, which briefly triggered warnings of a tsunami, although no such event occurred. However, the National Oceanic and Atmospheric Administration (NOAA) said that Hawaii had no expected threat of a tsunami despite a Pacific-wide warning.

    Thursday’s quake struck around 80 miles off the Russian coast, at a depth of 6 miles. Other officials reported tsunami waves of around 1 to 2 feet high at various points along the peninsula’s edge.

    An infographic shows the Pacific Ocean where tsunami advisories of various levels were issued after an 8.8 magnitude quake off the coast of Russia’s Kamchatka peninsula on July 30.

    John Saeki/AFP via Getty Images

    What To Know

    Aftershocks further disrupted the Kamchatka region, with a fresh one occurring virtually every hour throughout Friday.

    The U.S. Geological Survey (USGS) recorded 14 seismic activities during the last 12 hours. The agency reviewed and confirmed all of them, with no reports of immediate damage or injury.

    As of Friday evening ET, several hours had passed with no further quakes and tsunami warnings were not issued.

    The clustered timing and proximity of the quakes suggested a possible sequence of related seismic disturbances. Experts have yet to confirm whether they represent a pattern or independent ruptures along the same fault zone.

    Where Is Petropavlovsk-Kamchatsky in Russia?

    Kamchatka, along the volatile Pacific Ring of Fire, is among Russia‘s most seismically active regions.

    Perched on the edge of Avacha Bay in the Russian Far East, Petropavlovsk-Kamchatsky is the capital of Kamchatka Krai and one of the world’s most isolated major cities, accessible only by air or sea.

    The port city is surrounded by snow-capped volcanoes and rugged terrain, adding to its seismic vulnerability inside a tectonically active zone. But despite its isolation, Petropavlovsk-Kamchatsky remains a hub for scientists and tourists.

    What Happens Next

    Seismologists will continue monitoring the region for aftershocks and analyze the sequence for patterns that could indicate increased risk. Any further quakes could present a threat to the U.S. with tsunamis that could strike Alaska or Hawaii.

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  • Evidence of Ancient Asteroid Impact and Tsunami Found in North Carolina

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    Around 35 million years ago, a small asteroid traveling at 40,000 miles per hour (64,373 kilometers per hour) struck Earth, crashing into the Atlantic Ocean near the modern-day town of Cape Charles, Virginia. The approximately 3-mile-wide (5-kilometer) object created a large impact crater that’s buried half a mile beneath Chesapeake Bay. Hundreds of miles south of the crater, scientists have found new evidence of the asteroid impact and the tsunami that followed the shattering event.

    Hidden beneath the waters of the Chesapeake, the impact crater in Virginia is among the largest and most preserved craters found on Earth. The Chesapeake Bay crater was first discovered in 1990, and scientists are still trying to piece together the trail of destruction left by the asteroid. A team of geologists investigating fossils in Moore County, North Carolina, uncovered layers of rock they determined were forged by the asteroid impact and the tsunami that followed.

    In a recently published study in Southeastern Geology, scientists document the far-reaching impact of the asteroid collision, detailing the discovery of a site found approximately 240 miles (386 km) away from the Virginia crater in the Sandhills of North Carolina.

    Rocky beds

    The team of geologists behind the new study found four distinct beds of rock within a one-yard-thick layer formation at the site in Moore County. The first bed of rock is around 17 inches thick (43 centimeters) and contains sandy clay rich in carbon glass and rock fragments. The researchers also measured 14 to 18 parts per billion of iridium, a rare chemical element that’s often found in meteorites that land on Earth.

    The second bed of rock, measuring at only about 3 inches thick (9 centimeters), contained silt and loosely bound masses of quartz and carbon, as well as 2 to 6 parts per billion of iridium. Bed number 3 is a mix of soil and seafloor fragments and measures at around 2 inches thick (6 centimeters), while the fourth bed of rock is around 6 inches (15 centimeters) of coarse sand that may have been deposited by a tsunami.

    The geological makeup of the different rock beds made no sense when examined on its own, but the researchers behind the study traced it to the ancient asteroid that struck Virginia millions of years ago.

    Tsunami warning

    Around 35 million years ago, when the asteroid struck Earth, the impact created a hypersonic shock wave that destroyed plants and animals for hundreds of miles in each direction and rained huge amounts of molten debris in the area that stretches from Massachusetts to Barbados.

    When it was first discovered, scientists speculated that the impact that hit the Atlantic Ocean also likely caused a massive, far-reaching tsunami, but they had not found actual remains of it. The new study suggests that the strange rock formation in North Carolina traces all the way back to that fateful day when the asteroid struck Earth millions of years ago.

    The first rock bed records the initial impact, rich with ejecta and carbon-rich debris that had settled into the channel within the first minutes. Rock bed number two is an accumulation of the finer particles that were ejected as the plume thinned, while the third rock bed is a record of the inland surge of seawater and sediment. Finally, the fourth rock bed is when water refilled the channel with clean sand and gravel.

    The new finding adds further clarity to the Chesapeake Bay impact and how far-reaching it really was. As we’re learning, this lone asteroid, through this single cataclysmic encounter, reshaped an entire region so many million years ago.

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    Passant Rabie

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  • Study examines link between underwater landslides and tsunamis

    Study examines link between underwater landslides and tsunamis

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    Newswise — COLUMBUS, Ohio – Scientists have calculated a way to determine the speed of past underwater landslides, a new study has found. 

    Researchers from The Ohio State University studied the remains of an underwater landslide just off the coast of Oregon – dubbed the 44-N Slide – that is part of the Cascadia Subduction Zone (CSZ). 

    Stretching from Vancouver Island in Canada to Cape Mendocino in Northern California, the CSZ is a dipping fault line that has been the source of some of the most powerful earthquakes ever recorded. These quakes can result in underwater (also known as submarine) landslides, which can lead to tsunamis. 

    Now, using properties measured from distortions in the seafloor near the 44-N Slide, researchers have developed a novel approach for analyzing the risk that underwater landslides may trigger deadly tsunamis. 

    Previous research showed that large blocks from the 44-N Slide dropped down 1,200 meters at a 13-degree slope, and slid 10 kilometers horizontally before it finally came to a standstill. The researchers in this study investigated the shape and volume of the rock structures in the area where it was deposited, creating what’s called a “deformation zone.”  

    Their findings showed that the 44-N Slide was estimated to be moving at 60 meters per second during its fall, and impacted the seafloor with so much force that it created a 275-meter thick and 10-kilometer-long region of contorted and deformed seafloor sediment. Because of its velocity, it also likely could have been “tsunamigenic,” meaning it was powerful enough to have generated a huge tsunami on its own, though it’s unclear if that particular instance did.

    Researchers are unsure when the 44-N Slide might have occurred.

    “Just like on land, submarine landslides happen when giant masses of rock and sediment fall,” said Derek Sawyer, co-author of the study and an associate professor of earth sciences at The Ohio State University. “They can be really dangerous to people if they create tsunamis, which is why we want to understand how, when and why they form.”

    The study was published in the journal Geophysical Research Letters.

    Despite being a relatively common occurrence, known instances of tsunamigenic slides have been extremely limited. Moreover, discerning the type of underwater landslide and whether that event could cause such a disaster can be a challenging task – mainly because researchers are only able to interpret how fast these landslides travel from the deposits they leave behind, said Sawyer.  

    The minimum velocity needed for an underwater landslide to trigger a tsunami is still unconfirmed, Sawyer said. One piece of evidence is the Storegga Slides, a series of landslides that occurred in the Norwegian Sea over a period of thousands of years, which were estimated to have a speed of between 35-60 meters per second. It caused such massive tsunamis that some scientists believed it to be responsible for washing away the land bridge between Great Britain and the rest of Europe.

    The 1929 Grand Banks Earthquake also triggered underwater landslides and turbidity flows that moved between 15-30 meters per second, and caused tsunami waves so high that they destroyed a number of coastal communities. The underwater landslides themselves ripped apart underwater communication cables connecting the U.S. and Europe.

    “Submarine landslides can sometimes move so fast that they cause infrastructure damage to the global internet cables that line the ocean floor, as well as trigger and even amplify earthquake-caused tsunamis,” said Sawyer. 

    Nevertheless, both the Storegga Slides and the Grand Banks Earthquake served as a fount of knowledge for researchers striving to more closely examine the complexities behind these seismic-induced phenomena.

    “Because of the timing of the cable breaks, scientists could back-calculate how fast those flows were going, which was the first time we’d ever been able to do that in the marine environment,” said Sawyer. “The severity of these events, like how big the tsunami is or how dangerous it is, is tightly tied to how fast the landslide moves.”

    Deciphering how past landslides played out is vital, not only for protecting underwater cables, but also for people living on coastlines and policymakers who guide emergency response plans in response to tsunamis, said Sawyer. 

    After all, getting a better grip on the mechanics of underwater landslides could give the public time to prepare for the hazards they cause. But without better seafloor imaging technologies, past slides and threats from future ones could remain undetected, said Sawyer. 

    “We’re a long way off from really being able to predict with any degree of certainty what style of a landslide is likely to happen in the event of an earthquake,” he said. “But this type of study helps us understand the entire range of possible outcomes.”

    The techniques highlighted in the paper will also be made available to researchers interested in modeling underwater landslide deformation zones in other parts of the world. 

    This work was supported by the National Science Foundation. Other Ohio State co-authors were Ph.D student Brandi L. Lenz, now at Texas A&M University, and W. Ashley Griffith, an associate professor in earth sciences. 

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    Ohio State University

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  • Alaska scientists’ novel aid for earthquake magnitude

    Alaska scientists’ novel aid for earthquake magnitude

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    Newswise — Sensors that detect changes in atmospheric pressure due to ground shaking can also obtain data about large earthquakes and explosions that exceed the upper limit of many seismometers, according to new research.

    The sensors, which detect inaudible infrasounds carried through the air, could improve tsunami warnings and other emergency responses while also lowering costs.

    Research by University of Alaska Fairbanks Geophysical Institute scientists shows that infrasound sensors can improve magnitude determinations. An initial tsunami warning is based solely on estimated magnitude and location.

    Infrasound sensors cost less than seismometers, are reliable and exist in large numbers in Alaska for other uses.

    “What we’ve done is use infrasound for a purpose it wasn’t really intended for,” said Ken Macpherson at the Geophysical Institute’s Wilson Alaska Technical Center.“We’ve found that it works well for providing complete data about strong earthquakes.”

    These pressure-sensing infrasound instruments are generally used for non-seismic purposes such as the detection of mining explosions or nuclear detonations. They also record landslides, erupting volcanoes or meteors entering Earth’s atmosphere.

    Macpherson details the use of infrasound sensors for seismology in a research paper published April 21 in the Bulletin of the Seismological Society of America

    Macpherson is a seismo-acoustic research and operations scientist. Others from the Wilson Alaska Technical Center involved in the research include Director David Fee, data specialist  Juliann Coffey and machine-learning specialist Alex Witsil, now working in the private sector.

    Infrasound sensors record changes in air pressure caused by infrasound waves, which are at a frequency below what humans can hear. 

    Infrasound sensors can register the full range of an earthquake’s ground motion by detecting air pressure changes caused by the ground’s up and down movement during an earthquake. 

    Upward movement of the ground compresses the air, increasing air pressure much like a piston does. Downward movement reduces the pressure. 

    Pressure changes from even the largest earthquakes are far below infrasound sensors’ upper limit. 

    In contrast, seismometers, which record the actual movement of the ground, have an upper limit, meaning top-end data can be absent for large earthquakes. They can also miss data of smaller earthquakes if those occur too close to a seismometer.

    Seismologists call that data loss “clipping.”

    “If you crank up your stereo too high, you get a horrible sound,” Macpherson said. “That means you’ve exceeded the dynamic range of the speaker. That can happen to a seismometer.”

    Seismologists can overcome clipping by deploying strong-motion detectors, which are different from infrasound sensors. These motion sensors won’t go off scale during intense shaking but are costly and aren’t accurate for smaller quakes. About 130 are located around Alaska, mostly in urban areas and near known faults.

    As one example, Macpherson and his colleagues compared infrasound data of the magnitude 7.1 Anchorage earthquake of Nov. 30, 2018, to data from a seismometer. Both instruments were in the same location 18.6 miles from the epicenter.

    “The seismometer recording of that earthquake went right to the dynamic range of the instrument and stopped,” Macpherson said. “So there’s a loss of amplitude information.”

    The seismometer was one of several in the Southcentral Alaska region missing top-end data from that earthquake. Data from the infrasound sensor was not clipped.

    To check the accuracy of the infrasound monitor’s top-end data, Macpherson matched it against the data from a strong-motion seismometer at the same location. They matched.

    Infrasound sensors can also provide data just as timely as seismometers. That’s especially important if a tsunami is possible. The National Tsunami Warning Center has just four minutes to issue a warning from the time of a quake’s occurrence.

    “If all of the close seismometers clip, and the Tsunami Warning Center is trying to get an accurate magnitude for warning of a tsunami, they could quickly compute magnitudes from a nearby infrasound station that’s colocated with a seismometer,” Coffey said.

    Alaska has about 150 infrasound sensors alongside seismic monitors throughout the state. 

    Some of these were part of the EarthScope Transportable Array, a project funded by the National Science Foundation to map Earth’s crust and upper mantle. The temporary array moved gradually across the nation, reaching Alaska in 2014. Ninety-six of these stations are now part of the Alaska Earthquake Center’s permanent monitoring network

    “We have this unique resource in Alaska, and we’re pushing the science to get the most out of it that we can,” Macpherson said. “We’re looking to utilize it in novel ways.”

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    University of Alaska Fairbanks

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  • Small tsunami after massive 7.7-magnitude earthquake in South Pacific west of Fiji

    Small tsunami after massive 7.7-magnitude earthquake in South Pacific west of Fiji

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    A 7.7 magnitude earthquake caused a small tsunami to wash ashore on South Pacific islands Friday. No damage has been reported, and the threat passed after a few hours.

    The temblor was 23 miles deep.   

    Waves 2 feet above tide level were measured off Lenakel, a port town in Vanuatu, the Pacific Tsunami Warning Center said. Smaller waves were measured by coastal or deep-ocean gauges elsewhere off Vanuatu and off New Caledonia and New Zealand.

    Vanuatu’s National Disaster Management Office advised people to evacuate from coastal areas to higher grounds. The office said people should listen to their radios for updates and take other precautions.

    New Zealand’s National Emergency Management Agency said it expected coastal areas would experience strong and unusual currents, with unpredictable surges at the shoreline. The PTWC said small waves of 8 inches above tides were measured at North Cape, New Zealand.

    The tsunami danger passed within a few hours, though the center said small sea level changes may continue.

    Agence France-Presse reported that people on multiple South Pacific islands raced to higher ground as sirens warned of possible hazardous waves.

    “Based on all available data the tsunami threat from this earthquake has now passed,” AFP quotes the Pacific Tsunami Warning Center said in a statement.

    Earlier, the Hawaii Emergency Management Agency said there was “no tsunami threat” to Hawaii from the earthquake, while the U.S. National Tsunami Warning Center said a tsunami was “not expected” for the West Coast.

    The U.S. Geological Survey said the quake’s epicenter was near the Loyalty Islands, a province in the French territory of New Caledonia.

    The area is southwest of Fiji, north of New Zealand and east of Australia where the Coral Sea meets the Pacific.

    The region is part of the “Ring of Fire,” an arc of seismic faults around the Pacific Ocean where most of the world’s earthquakes occur.

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  • Tsunami warning as magnitude 7.7 quake hits near New Caledonia

    Tsunami warning as magnitude 7.7 quake hits near New Caledonia

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    DEVELOPING STORY,

    Pacific Tsunami Warning Centre says waves of up to 3 metres (10 feet) possible for Vanuatu.

    A magnitude 7.7 earthquake struck the Pacific Ocean southeast of New Caledonia, triggering a tsunami warning, US monitoring agencies say.

    The quake was detected at a depth of 37km (23 miles), the US Geological Service said on Friday.

    “Based on the preliminary earthquake parameters, hazardous tsunami waves are possible for coasts within 1,000km (620 miles) of the earthquake epicentre,” the Pacific Tsunami Warning Centre (PTWC) said in a bulletin.

    It urged people in threatened coastal areas to be alert.

    The PTWC said waves up to 3 metres (10 feet) above tides were possible for Vanuatu.

    Smaller waves were possible for Fiji, New Caledonia, Kiribati and New Zealand.

    The Vanuatu Meteorology and Geo-Hazards Department said an earthquake of such magnitude had the potential to cause “destructive Tsunami waves” of 1-3 metres (3-10 feet) that could strike Vanuatu coastlines.

    The National Disaster Management Office advised people “to take appropriate action and precautionary measures, including “immediate evacuation from coastal areas to higher grounds”, according to an information bulletin on the department’s website.

    Australia’s Bureau of Meteorology said there was no tsunami threat to mainland Australia but Lord Howe Island – located 780km (421 nautical miles) northeast of Sydney in the Tasman Sea – was under a threat warning.

    New Zealand’s National Emergency Management Agency said it was still assessing the potential for a tsunami.

    More to follow soon.

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  • Immigration experts on Title 42, analysis of immigration policies, and other migrant news in the Immigration Channel

    Immigration experts on Title 42, analysis of immigration policies, and other migrant news in the Immigration Channel

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    Title 42, the United States pandemic rule that had been used to immediately deport hundreds of thousands of migrants who crossed the border illegally over the last three years, has expired. Those migrants will have the opportunity to apply for asylum. President Biden’s new rules to replace Title 42 are facing legal challenges. The US Homeland Security Department announced a rule to make it extremely difficult for anyone who travels through another country, like Mexico, to qualify for asylum. Border crossings have already risen sharply, as many migrants attempted to cross before the measure expired on Thursday night. Some have said they worry about tighter controls and uncertainty ahead. Immigration is once again a major focus of the media as we examine the humanitarian, political, and public health issues migrants must face. 

    Below are some of the latest headlines in the Immigration channel on Newswise.

    Expert Commentary

    Experts Available on Ending of Title 42

    George Washington University Experts on End of Title 42

    ‘No one wins when immigrants cannot readily access healthcare’

    URI professor discusses worsening child labor in the United States

    Biden ‘between a rock and a hard place’ on immigration

    University of Notre Dame Expert Available to Comment on House Bill Regarding Immigration Legislation, Border Safety and Security Act

    American University Experts Available to Discuss President Biden’s Visit to U.S.-Mexico Border

    Title 42 termination ‘overdue’, not ‘effective’ to manage migration

    Research and Features

    Study: Survey Methodology Should Be Calibrated to Account for Negative Attitudes About Immigrants and Asylum-Seekers

    A study analyses racial discrimination in job recruitment in Europe

    DACA has not had a negative impact on the U.S. job market

    ASBMB cautions against drastic immigration fee increases

    Study compares NGO communication around migration

    Collaboration, support structures needed to address ‘polycrisis’ in the Americas

    TTUHSC El Paso Faculty Teach Students While Caring for Migrants

    Immigrants Report Declining Alcohol Use during First Two Years after Arriving in U.S.

    How asylum seeker credibility is assessed by authorities

    Speeding up and simplifying immigration claims urgently needed to help with dire situation for migrants experiencing homelessness

    Training Individuals to Work in their Communities to Reduce Health Disparities

    ‘Regulation by reputation’: Rating program can help combat migrant abuse in the Gulf

    Migration of academics: Economic development does not necessarily lead to brain drain

    How has the COVID-19 pandemic affected immigration?

    Immigrants with Darker Skin Tones Perceive More Discrimination

     

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  • Solomon Islands shaken by huge earthquake, tsunami alert issued

    Solomon Islands shaken by huge earthquake, tsunami alert issued

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    Pacific nation’s government advises people to move to higher ground following magnitude 7.0 quake

    A large earthquake has been reported near the Solomon Islands in the Pacific.

    A tsunami warning was issued for an area of the coast within 300km (185 miles) of the epicentre, and the prime minister’s office urged people to move to higher ground.

    Michael Salini, a businessman and political commentator on Tulagi Island, which lies across from Honiara, told Al Jazeera that people were “very worried”.

    “Everyone has run up the hills and [are waiting] for any possible tsunami warning,” he added, saying that most people were aware of the signs of a tsunami.

    The earthquake cut power to some areas of Honiara and the state broadcaster was also down, but the government said there was no major damage to buildings in the capital.

    “This was a big one,” Joy Nisha, a receptionist with the Heritage Park Hotel in the capital Honiara, told the AFP news agency. “Some of the things in the hotel fell. Everyone seems OK, but panicky.”

    The United States Geological Survey said the magnitude 7.0 earthquake struck the Malango region, about 55km (34 miles) west of the capital, at a depth of 15km (9 miles). It revised the size of the tremor from an earlier magnitude of 7.3.

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