Latest news with #NationalSeismicHazardModel
Yahoo
28-04-2025
- Science
- Yahoo
Cascadia subduction zone earthquake could be even worse than feared
When an earthquake rips along the Cascadia Subduction Zone fault, much of the U.S. west coast could shake violently for five minutes, and tsunami waves as tall as 100 feet could barrel toward shore. But that's just the start of the expected horrors. Even if coastal towns in Northern California, Oregon and Washington withstand that seismic onslaught, new research suggests floodwaters could seep into many of these vulnerable communities for good. That's because entire coastal shorelines are expected to drop by as much as 6½ feet when the earthquake strikes, according to new research, published Monday in the Proceedings of the National Academy of Sciences (PNAS). Researchers analyzed seismic and flood modeling to produce some of the most detailed estimates of how the Cascadia earthquake would drop — or subside — coastal shorelines and found that it could affect more than double the number of people, structures and roads currently at risk. The effect will also worsen over time, as intensifying climate change raises sea levels further. 'This lesser talked about hazard is going to persist for decades or centuries after the earthquake,' said Tina Dura, the study's lead author. 'The tsunami will come in and wash away and it's going to have big impacts, don't get me wrong, but the lasting change of the frequency of flooding … that's going to have to be dealt with.' Dura said geologic fossil evidence shows that previous Cascadia earthquakes immediately dropped the land level and turned dry ground into tidal mudflats in estuaries along the Pacific Northwest. 'That's going to happen again and we've built up a lot of those areas,' said Dura, who is an assistant professor of geosciences at Virginia Tech University. 'That's how we have ports there ... and that's where we built towns, and all that area is gonna drop down maybe over a meter, up to two meters.' The Cascadia Subduction Zone fault, which runs offshore along North America's west coast from Northern California to northern Vancouver Island, represents a looming threat. The fault has the capability to produce a magnitude-9.0 earthquake, and a large temblor is expected there at least once every 450-500 years, on average. The last of those major quakes occurred in 1700. The National Seismic Hazard Model suggests there is a 15% chance a magnitude-8.0 earthquake or stronger will rupture along the zone's margin within the next 50 years. When the fault rips, experts have said it will precipitate the worst natural disaster in the nation's history. A 2022 state and federal planning exercise for a Cascadia earthquake predicted about 14,000 fatalities, more than 100,000 injuries and the collapse of about 620,000 buildings in the Pacific Northwest, including 100 hospitals and 2,000 schools. The new research suggests that coastal planners must seriously reckon not only for the threat of intense shaking and tsunami waves, but also for the long-term reshaping and rapid sinking of the coastline itself. 'There's the flood itself and then there's the basically permanent change to land level at the coast and that has a big impact for what those communities have to plan for,' said Harold Tobin, the director of the Pacific Northwest Seismic Network and a professor at the University of Washington, who was not involved in the new research. 'Where are you going to put your school or hospital? Where are you going to build your transportation network? I think it's important to take the long view.' After the earthquake, Dura's research suggests, large portions of towns along the Pacific Northwest coastline, such as Seaside, Oregon; Westport, Washington; and Aberdeen, Washington, would be expected to flood at least once every 100 years, if not more often. The study also points out that sea level rise is accelerating as climate change intensifies, and the effects of post-earthquake flooding could worsen in the future. Global mean sea levels have risen by about 8 to 9 inches since 1880, according to the National Oceanic and Atmospheric Administration. Sea level rise is expected to dramatically accelerate in coming decades because of global warming, with NOAA predicting another 10 to 12 inches on average by midcentury. Where you live could determine how dramatic sea level rise appears, and how it affects the coastline. While land in some regions of the U.S., like the Chesapeake Bay in Virginia, is slowly sinking in a process called subsidence, parts of the Pacific Northwest have been rising because of continental uplift. That rise in land level has offset some of the sea level rise to date. The uplift is the result of stress building up within the tectonic plates that form the Cascadia subduction zone offshore. At the subduction zone, the Juan de Fuca plate is being forced beneath the continental North American plate. This causes the North American plate to bow upward slightly, pushing the land level higher. Right now, the subduction zone fault is quiet and building stress. When the fault ruptures, the bowing of the plate will release and cause a rapid subsidence of the land level, essentially erasing centuries of uplift in an instant. 'That happens in minutes, and it can be on the order of meters,' Dura said. 'The land persists down, and that can be for, like I said, decades and centuries. And so any areas that are kind of on the cusp of the floodplain are now in it." This article was originally published on
NBC News
28-04-2025
- Science
- NBC News
Cascadia subduction zone earthquake could be even worse than feared
When an earthquake rips along the Cascadia Subduction Zone fault, much of the U.S. west coast could shake violently for five minutes, and tsunami waves as tall as 100 feet could barrel toward shore. But that's just the start of the expected horrors. Even if coastal towns in Northern California, Oregon and Washington withstand that seismic onslaught, new research suggests floodwaters could seep into many of these vulnerable communities for good. That's because entire coastal shorelines are expected to drop by as much as 6½ feet when the earthquake strikes, according to new research, published Monday in the Proceedings of the National Academy of Sciences (PNAS). Researchers analyzed seismic and flood modeling to produce some of the most detailed estimates of how the Cascadia earthquake would drop — or subside — coastal shorelines and found that it could affect more than double the number of people, structures and roads currently at risk. The effect will also worsen over time, as intensifying climate change raises sea levels further. 'This lesser talked about hazard is going to persist for decades or centuries after the earthquake,' said Tina Dura, the study's lead author. 'The tsunami will come in and wash away and it's going to have big impacts, don't get me wrong, but the lasting change of the frequency of flooding … that's going to have to be dealt with.' Dura said geologic fossil evidence shows that previous Cascadia earthquakes immediately dropped the land level and turned dry ground into tidal mudflats in estuaries along the Pacific Northwest. 'That's going to happen again and we've built up a lot of those areas,' said Dura, who is an assistant professor of geosciences at Virginia Tech University. 'That's how we have ports there ... and that's where we built towns, and all that area is gonna drop down maybe over a meter, up to two meters.' The Cascadia Subduction Zone fault, which runs offshore along North America's west coast from Northern California to northern Vancouver Island, represents a looming threat. The fault has the capability to produce a magnitude-9.0 earthquake, and a large temblor is expected there at least once every 450-500 years, on average. The last of those major quakes occurred in 1700. The National Seismic Hazard Model suggests there is a 15% chance a magnitude-8.0 earthquake or stronger will rupture along the zone's margin within the next 50 years. When the fault rips, experts have said it will precipitate the worst natural disaster in the nation's history. A 2022 state and federal planning exercise for a Cascadia earthquake predicted about 14,000 fatalities, more than 100,000 injuries and the collapse of about 620,000 buildings in the Pacific Northwest, including 100 hospitals and 2,000 schools. The new research suggests that coastal planners must seriously reckon not only for the threat of intense shaking and tsunami waves, but also for the long-term reshaping and rapid sinking of the coastline itself. 'There's the flood itself and then there's the basically permanent change to land level at the coast and that has a big impact for what those communities have to plan for,' said Harold Tobin, the director of the Pacific Northwest Seismic Network and a professor at the University of Washington. 'Where are you going to put your school or hospital? Where are you going to build your transportation network? I think it's important to take the long view.' After the earthquake, Dura's research suggests, large portions of towns along the Pacific Northwest coastline, such as Seaside, Oregon; Westport, Washington; and Aberdeen, Washington, would be expected to flood at least once every 100 years, if not more often. The study also points out that sea level rise is accelerating as climate change intensifies, and the effects of post-earthquake flooding could worsen in the future. Global mean sea levels have risen by about 8 to 9 inches since 1880, according to the National Oceanic and Atmospheric Administration. Sea level rise is expected to dramatically accelerate in coming decades because of global warming, with NOAA predicting another 10 to 12 inches on average by midcentury. Where you live could determine how dramatic sea level rise appears, and how it affects the coastline. While land in some regions of the U.S., like the Chesapeake Bay in Virginia, is slowly sinking in a process called subsidence, parts of the Pacific Northwest have been rising because of continental uplift. That rise in land level has offset some of the sea level rise to date. The uplift is the result of stress building up within the tectonic plates that form the Cascadia subduction zone offshore. At the subduction zone, the Juan de Fuca plate is being forced beneath the continental North American plate. This causes the North American plate to bow upward slightly, pushing the land level higher. Right now, the subduction zone fault is quiet and building stress. When the fault ruptures, the bowing of the plate will release and cause a rapid subsidence of the land level, essentially erasing centuries of uplift in an instant. 'That happens in minutes, and it can be on the order of meters,' Dura said. 'The land persists down, and that can be for, like I said, decades and centuries. And so any areas that are kind of on the cusp of the floodplain are now in it."
Yahoo
31-03-2025
- Politics
- Yahoo
US earthquake safety relies on federal employees' expertise
Earthquakes and the damage they cause are apolitical. Collectively, we either prepare for future earthquakes or the population eventually pays the price. The earthquakes that struck Myanmar on March 28, 2025, collapsing buildings and causing over 2,000 deaths, were a sobering reminder of the risks and the need for preparation. In the U.S., this preparation hinges in large part on the expertise of scientists and engineers in federal agencies who develop earthquake hazard models and contribute to the creation of building codes designed to ensure homes, high-rises and other structures won't collapse when the ground shakes. Local communities and states decide whether to adopt building code documents. But those documents and other essential resources are developed through programs supported by federal agencies working in partnership with practicing engineers and earthquake experts at universities. This essential federal role is illustrated by two programs that we work closely with as an earthquake engineer and a disaster management expert whose work focuses on seismic risk. First, seismologists and earthquake engineers at the U.S. Geological Survey, or USGS, produce the National Seismic Hazard Model. These maps, based on research into earthquake sources such as faults and how seismic waves move through the earth's crust, are used to determine the forces that structures in each community should be designed to resist. A steering committee of earthquake experts from the private sector and universities works with USGS to ensure that the National Seismic Hazard Model implements the best available science. Second, the Federal Emergency Management Agency, FEMA, supports the process for periodically updating building codes. That includes supporting the work of the National Institute of Building Sciences' Provisions Update Committee, which recommends building code revisions based on investigations of earthquake damage. More broadly, FEMA, the USGS, the National Institute of Standards and Technology and the National Science Foundation work together through the National Earthquake Hazards Reduction Program to advance earthquake science and turn knowledge of earthquake risks into safer standards, better building design and education. Some of those agencies have been threatened by potential job and funding cuts under the Trump administration, and others face uncertainty regarding continuation of federal support for their work. It is in large part because of the National Seismic Hazard Model and regularly updated building codes that U.S. buildings designed to meet modern code requirements are considered among the safest in the world, despite substantial seismic hazards in several states. This paradigm has been made possible by the technical expertise and lack of political agendas among the federal staff. Without that professionalism, we believe experts from outside the federal government would be less likely to donate their time. The impacts of these and other programs are well documented. We can point to the limited fatalities from U.S. earthquakes such as the 1989 Loma Prieta earthquake near San Francisco, the 1994 Northridge earthquake in Los Angeles and the 2001 Nisqually earthquake near Seattle. Powerful earthquakes in countries lacking seismic preparedness, often due to lack of adoption or enforcement of building codes, have produced much greater devastation and loss of life. These programs and the federal agencies supporting them have benefited from a high level of staff expertise because hiring and advancement processes have been divorced from politics and focused on qualifications and merit. This has not always been the case. For much of early U.S. history, federal jobs were awarded through a patronage system, where political loyalty determined employment. As described in 'The Federal Civil Service System and The Problem of Bureaucracy,' this system led to widespread corruption and dysfunction, with officials focused more on managing quid pro quo patronage than governing effectively. That peaked in 1881 with President James Garfield's assassination by Charles Guiteau, a disgruntled supporter who had been denied a government appointment. The passage of the Pendleton Act by Congress in 1883 shifted federal employment to a merit-based system. This preference for a merit-based system was reinforced in the Civil Service Reform Act of 1978. It states as national policy that 'to provide the people of the United States with a competent, honest, and productive workforce … and to improve the quality of public service, Federal personnel management should be implemented consistent with merit system principles.' The shift away from a patronage system produced a more stable and efficient federal workforce, which has enabled improvements in many critical areas, including seismic safety and disaster response. While the work of these federal employees often goes unnoticed, the benefits are demonstrable and widespread. That becomes most apparent when disasters strike and buildings that meet modern code requirements remain standing. A merit-based civil service is not just a democratic ideal but a proven necessity for the safety and security of the American people, one we hope will continue well into the future. This can be achieved by retaining federal scientists and engineers and supporting the essential work of federal agencies. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Jonathan P. Stewart, University of California, Los Angeles and Lucy Arendt, St. Norbert College Read more: If FEMA didn't exist, could states handle the disaster response on their own? Acapulco was built to withstand earthquakes, but not Hurricane Otis' destructive winds – how building codes failed this resort city What causes earthquakes? A geologist explains where they're most common and why Jonathan P. Stewart has received funding from NSF and USGS. He is the chair of the Steering Committee for the National Seismic Hazard Model, a member of the National Institute of Building Sciences' Provisions Update Committee, and a member of the federal Advisory Committee for Earthquake Hazard Reduction (ACEHR). His contributions to this article draw upon his experience and do not reflect the views of the Steering Committee, Provisions Update Committee, or ACEHR. Lucy Arendt has received funding from NSF and the Applied Technology Council. She is a member and current chair of the federal Advisory Committee for Earthquake Hazard Reduction (ACEHR). Her contributions to this article reflect her professional expertise and do not reflect the views of ACEHR.
Yahoo
27-01-2025
- Science
- Yahoo
Earthquake rattles Maine and Boston. How common are quakes in the Northeast?
Residents throughout New England, including Boston, felt the ground shake beneath their feet Monday when an earthquake struck off the coast of Maine. According to the U.S. Geological Survey (USGS), the 3.8 magnitude earthquake was located about 6 miles southeast of York Harbor, Maine, at 10:22 a.m. ET. There were no immediate reports of damage or injuries. The quake could be felt in at least six states — Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut and Vermont — according to a map published by the USGS. Small earthquakes are not uncommon in the Northeast, John Ebel, a senior scientist at the Weston Observatory at Boston College, told Yahoo News. See for yourself — The Yodel is the go-to source for daily news, entertainment and feel-good stories. By signing up, you agree to our Terms and Privacy Policy. Earthquakes measuring magnitude 2.0 or less are recorded several times a month — and most are not widely felt, Ebel said. But earthquakes at magnitudes near 4.0 — like Monday's quake in New England— are far less common in the region. 'This is a once-in-every-five-years kind of earthquake,' Ebel said. Or twice. In April 2024, a 4.8 magnitude earthquake centered in New Jersey was felt up and down the East Coast. Earlier this month, the USGS published a new map showing where damaging earthquakes are most likely to occur in the United States. The National Seismic Hazard Model found that nearly 75% of the United States could experience potentially damaging earthquakes, including places not highlighted before. 'Noteworthy changes in the new model show the possibility of more damaging earthquakes along the central and northeastern Atlantic Coastal corridor, including in the cities of Washington, D.C., Philadelphia, New York and Boston,' according to the USGS. Ebel said such models are not meant for fearmongering but are used to update building codes to withstand stronger earthquakes. According to the USGS, the most recent New England earthquake causing moderate damage occurred in 1940 (magnitude 5.6) in central New Hampshire.
Yahoo
27-01-2025
- Climate
- Yahoo
Earthquake rattles Maine and Boston. How common are they in the Northeast?
Residents throughout New England and Boston felt the ground shake beneath their feet Monday when an earthquake struck off the coast of Maine. According to the U.S. Geological Survey, the 3.8-magnitude earthquake was located about 6 miles southeast of York Harbor, Maine, at 10:22 a.m. ET. There were no immediate reports of damage or injuries. The quake could be felt in at least five states — Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut and Vermont — according to a map published by the USGS. Small earthquakes are not uncommon in the northeast, John Ebel, a senior scientist at the Weston Observatory at Boston College, told Yahoo News. Earthquakes measuring magnitude 2.0 or less are recorded several times a month — and most are not widely felt, Ebel said. But earthquakes at magnitudes near 4.0 — like Monday's quake in New England— are far less common in the region. 'This is a once-in-every-five-years kind of earthquake,' Ebel said. Or twice. In April 2024, a 4.8 magnitude earthquake centered in New Jersey was felt up and down the East Coast. Earlier this month, the USGS published a new map showing where damaging earthquakes are most likely to occur in the United States. The so-called National Seismic Hazard Model found that nearly 75% of the United States could experience potentially damaging earthquakes, including places not highlighted before. 'Noteworthy changes in the new model show the possibility of more damaging earthquakes along the central and northeastern Atlantic Coastal corridor, including in the cities of Washington D.C., Philadelphia, New York and Boston,' the USGS said. Ebel said such models are not meant for fearmongering, but are used as a basis to update building codes to withstand stronger earthquakes. Per USGS, the most recent New England earthquake to cause moderate damage occurred in 1940 (magnitude 5.6) in central New Hampshire.
