How an outburst flood could wash out vulnerable American communities
But scientists say an 'outburst flood' could deliver more destruction than 90 of the most powerful nuclear bombs in history. Officially known as glacial lake outburst floods (GLOFs), they're becoming increasingly common due to climate change , and millions of people, including thousands in the US, are in harm's way. GLOFs are not new, but the scale and frequency are rising fast.
At the end of the last Ice Age, roughly 15,000 years ago, the Missoula Floods swept across the American Northwest, triggered by massive glacial lakes bursting through ice dams. This catastrophic event all started with a remote glacial lake quietly growing in size, swelling more than twelvefold as melting ice relentlessly fed it. However, after several decades, the water became too much. With immense pressure building behind a ridge, the lake exploded, unleashing a wall of water up to 60ft that roared down a valley, obliterating everything in its path.
Each of the 400 individual floods during this event unleashed the energy of 4,500 megatons of TNT, nearly 100 times the force of the largest nuclear weapon ever detonated, Soviet Russia's 'Tsar Bomba.' Water roared at speeds of 65 miles per hour, carrying boulders the size of cars, reshaping the landscape and carving vast canyons that are still visible today. In 2023, India's Sikkim region suffered the deadliest GLOF in recent memory, when a glacial lake burst following years of steady melt, killing dozens and leaving hundreds homeless.
Now, attention is turning to the US, where three states - Alaska, Washington and Wyoming - are facing growing threats. One Alaskan lake, ominously named [Death] Basin, has burst two years in a row, releasing a staggering 14.6billion gallons of water in each event. That's the equivalent of 22,000 Olympic swimming pools flooding downtown Juneau, turning streets into rivers and forcing residents to flee with pets in carriers.
Floods beneath the basin have been recorded since 2011, but researchers are now alarmed at the rapid acceleration. A recent study found 106 out of 120 glacier-dammed lakes in Alaska have drained at least once since 1985, and new lakes are forming as the glaciers retreat. 'The danger is growing,' scientists warned. 'As ice-free basins fill with water, they eventually reach a breaking point. 'Pressure builds until the glacier can't hold, and the result is a sudden, violent flood downstream.'
These floods, they say, are often unpredictable and have already caused significant loss of life and infrastructure worldwide. Washington State was once the site of the legendary Missoula Floods, and experts say history could repeat itself. All 47 glaciers currently monitored in the state are retreating, creating new lakes in unstable terrain.
Back in 1947, a combination of rain and glacial melt triggered a GLOF from the Kautz Glacier, sending 1.4 billion tons of mud and debris surging six miles and carving a canyon 300 feet deep. Now, the northeastern region of the state is considered a GLOF hotspot, and scientists have called for more urgent monitoring. In 2025, a panel of glaciologists urged the installation of seismic sensors and real-time weather stations to detect potential bursts before they happen.
Despite advances in modeling and hazard mapping, the team wrote in the science journal called Nature, 'These events continue to cause large-scale destruction due to weak policy enforcement, inadequate warning systems and poor community preparedness.' While not as high-risk as Alaska, Wyoming's Wind River Range and Absaroka Mountains have experienced multiple GLOFs, and the state remains on alert. In 2003, the Grasshopper Glacier released 3.2 million cubic meters of water, damaging nearby infrastructure.
A study using NASA Landsat satellite data found 13 separate GLOFs between 1994 and 2007, and local records have identified at least 15 total outbursts around Mammoth Glacier alone. That's the highest concentration of GLOFs documented in the Rockies since the Ice Age-era Missoula Floods. 'Glacial retreat is exposing new terrain where meltwater can accumulate,' scientists wrote. 'Eventually, these lakes become unstable, and when they go, they go fast.'
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The Guardian
14 hours ago
- The Guardian
Century-old dam under strain as floods increase in US and federal funds dry up
More than 18,000 properties that sit downstream of a series of a century-old Ohio dam are at risk of flooding over the next three decades, according to climate data, as the Trump administration continues to roll back investments that would aid in keeping the waters at bay. In a part of the US that's largely flat, the view from above the Huffman dam in south-west Ohio is rare. From the bike trail atop the dam, the shimmering lights of downtown Dayton appear to the south. Cargo planes from a nearby air force base circle overhead and water from the 66-mile-long Mad River gushes underfoot. But the dam serves a far more pressing purpose: holding back up to 54bn gallons of water – enough to fill 82,000 Olympic-size swimming pools – during flooding events. Nearby, more than 21% of all properties downstream are at risk of flooding over the next three decades, according to First Street, a climate risk data modeling organization. That percentage accounts for 18,596 properties in Dayton. The five massive dry dams and 55 miles of levees west and north of Dayton were built in the aftermath of catastrophic destruction that befell the Ohio city in 1913, when 360 people died and flooding in three rivers that meet in the city center wiped out the downtown area. But today, it and many other communities around the midwest are once again at risk of flooding. 'Our system has experienced 2,170 storage events. The flood in April ranked 12th,' says MaryLynn Lodor, general manager of the Miami Conservancy District, the authority overseeing the regional flood prevention system that includes the Huffman Dam. The flooding early last April saw five to seven inches of rain inundate homes, roads and parks, and caused power outages for thousands of people across hundreds of miles. Extreme precipitation events are happening with increasing regularity at a time when, across a region that's home to the country's two major, high-discharge waterways – the Ohio and Mississippi rivers – decades-old flood prevention infrastructure is falling apart. From Indiana, where authorities in charge of a dam at a youth camp that sees 15,000 visitors annually warned of failure during last April's flooding, to Illinois and Minnesota, reports are appearing with increasing regularity of '100-year' floods threatening the integrity of, and in some cases destroying, dams. Five years ago, the Edenville Dam in central Michigan failed following days of heavy rain, prompting the evacuation of 10,000 people and the failure of another dam downstream. The dam is situated at the confluence of two rivers, and in 2018 its owner temporarily had its license taken away due to fears it couldn't pass enough water at high flood levels. Lawsuits and an expense report of $250m followed the dam failure. Data from Michigan's department of environment, Great Lakes and energy, found that of the state's recorded 2,552 dams, nearly 18% were rated as in 'fair', 'poor' or 'unsatisfactory' condition. Despite this, little change has been enacted in Michigan. 'The reason this is popping up everywhere in the country is because it's a massive ageing infrastructure problem,' says Bryan Burroughs, a member of a now-closed state taskforce that sought to investigate the status of dams across Michigan following the Edenville incident. He says the taskforce's recommendations have largely not been enacted. 'To date, the only ones that have been taken up and addressed to any level are the ones that our state department of environment, Great Lakes and energy are able to oversee themselves. Regulatory changes have not been picked up legislatively,' Burroughs continued. Through the Inflation Reduction Act, the Biden administration had made investing in America's ageing infrastructure over the course of many years a priority, with $10bn dedicated to flooding mitigation and drought relief. An additional $3bn was allocated in 2021 through the Infrastructure Investment and Jobs Act for dam safety, removal and related upgrades. Since Donald Trump entered the White House in January, the administration has vowed to roll back much of those investments. Hundreds of dam safety and other staffers working at dams in 17 western states have been laid off in recent months. Before the 4 July flood disaster in Texas, the Trump administration had pledged to close the Federal Emergency Management Agency (Fema). With more than 92,000 dams across the country, the Society of Civil Engineers estimates the cost of repairing the country's non-federal dams at $165bn. In Ohio, the Miami Conservancy District has been outspoken in highlighting that the dams it is responsible for are in need of repair – in particular, the upstream walls of two north of the city of Dayton. Levees it manages 'are subject to the costly, federally mandated Fema accreditation process, but there is no adequate funding source.' Last year, the district said it needs $140m to bring the region's dams and levees up to safe levels over the coming decades. Over the past 80 years, the organization has seen a 228% increase in the volume of water its dams store, meaning the structures today must work harder than they did in the past to hold back the water. 'As we're looking at having to make reinvestments, we are looking to try to secure some funding through the state and federal governments,' says Lodor. 'We have not gotten much support and federal dollars or state money to be able to do the system. It's already been invested in by the local communities; it would be very difficult for this to be on the backs of the locals.' Many dams hold back water that's used by fishers and recreators – an issue that's creating tension in many communities. In White Cloud, Michigan, authorities have had to draw down much of the lake water behind a 150-year-old dam due to fears for its structural integrity, angering locals. As in Texas, dozens of youth groups and Christian camps across the midwest use lakes and waterways downstream of ageing lowhead and other dams for programming and outdoor activities. Emails and messages left by the Guardian with the owners of an at-risk dam at a camp in Indiana used by thousands of children every year received no response. While compared with other parts of the US the midwest does not have a lot of dams whose main purpose is for flood control due to geological and topographical reasons, Ohio and much of the wider midwest have seen 'record-setting rain' this year. 'The weather has changed,' says Burroughs. 'What used to be a one-in-100-year flood event might have happened three times in the last 40 years.'
Daily Mail
a day ago
- Daily Mail
Why 'corn sweat' is to blame for massive 100-degree heat dome affecting 200 million Americans ALL WEEK
'Corn sweat' has turned up the heat in the US, pushing temperatures above 100 degrees for nearly 200 million people nationwide. A thick wave of extreme humidity is expected to hit at least 30 states from the Plains to the East Coast boiling in a massive heat dome this week, with temperatures rising over 100 degrees, and scientists say 'corn sweat' is making the heat feel even worse. As corn reaches its peak growth phase across the Corn Belt, in states like Iowa and Illinois, the fields started acting like steam machines, fueling dangerous heat that could last through the weekend. They have started pumping thousands of gallons of water per acre into the air each day through a process called evapotranspiration, or corn sweat. That moisture gets trapped under the heat dome, turning the region into a huge sauna. That heat dome is like a hot air bubble covering an area and trapping heat like a lid on a pot, keeping cooler air and rainstorms out. This makes everything underneath get hotter and hotter, with no way to cool down. Officials warned that the heat index is expected to reach 110 to 115 degrees in parts of Missouri, Illinois, Iowa, and Indiana. Major Midwest cities like Kansas City, Des Moines, and Chicago are all under heat watches or warnings through the night, as meteorologists have said the air will stay thick and damp even after the sun sets. Justin Glisan, an Iowa State University climatologist, said: 'The phenomenon as being thick and oppressive, particularly if there is no wind, like being fully clothed in a sauna or steam room.' According to AccuWeather, more than 200 million people across 37 states will experience the triple-digit heat wave by Friday. Officials have issued extreme heat alerts for the Mississippi Valley, while the entire Chicago area is under an extreme heat watch through Thursday. This week, humidity from cornfields has intensified the already severe heat dome, extending from Texas to the Great Lakes. Over 100 cities are expected to challenge overnight heat records, raising serious risks for heat stress, especially where there is no air conditioning. The timing of this summer scorcher is no coincidence, as it coincides with the blossoming period of the corn plant. In Iowa alone, corn is planted across millions of acres. On Thursday and Friday, the heat dome will expand further east, covering the regions that rarely see this level of heat and humidity, especially New England and parts of the Northeast. In Maine, where summer temperature usually stay in the 70s or low 80s, it could reach the 90s by Friday. Portland is most likely to hit 94 degrees, but humidity will make it feels live over 100 Fahrenheit. Boston will also get very hot, with temperatures near 100 when you factor in the moisture in the air. Even cities near the coast would not be safe from the heat. Meteorologists say this heat will be short but strong. It's not like the long-lasting heat in the Plains, but it still could cause problems. The heat comes from moisture moving east, mostly from the Midwest's corn fields, which release a lot of water vapor into the air. This makes the air feel even hotter. New York City will see some of its hottest days this month with highs in the mid-90s and nights staying warm near 80 degrees. Many cities in the South and Midwest will also stay hot at night, giving little relief from the heat. Places like Little Rock and Jackson could see nighttime lows only reach the 80s. Corn in states like Iowa, Illinois, and Indiana is at a stage where it releases lots of moisture, which adds to the humidity spreading east. Washington, DC, will hit 97 degrees Friday, but it will feel hotter, between 105 and 110 because of the extra humidity coming from the South and Midwest. According to AccuWeather, Dallas will reach over 100 degrees, and Houston and San Antonio will stay in the triple digits. Forecasters say the Central Plains, including Kansas and Nebraska, could shift from humid to dangerously dry by mid-August. The heat will worsen with dry ground, pushing temperatures from the upper 90s to 100, with some areas possibly hitting 110 degrees Fahrenheit. AccuWeather Senior Meteorologist Chad Merrill said: 'The bottom line is that this has the look of a long-lasting heat wave with limited rainfall.' The Corn Belt is not in a drought right now, but that could change. As the ground dries under this heat dome, less water will evaporate to cool the air, and actual temperatures will rise even more. Some areas could climb to 110 degrees or more. Even tropical moisture from the Gulf would not help much. High pressure is blocking it from moving north in most places, and whatever rain does fall likely would not be enough to cut the heat.
Daily Mail
a day ago
- Daily Mail
Scientists: Why 'corn sweat' is to blame for 100-degree heat dome
'Corn sweat' has turned up the heat in the US, pushing temperatures above 100 degrees for nearly 200 million people nationwide. A thick wave of extreme humidity is expected to hit at least 30 states from the Plains to the East Coast boiling in a massive heat dome this week, with temperatures rising over 100 degrees, and scientists say 'corn sweat' is making the heat feel even worse. That moisture gets trapped under the heat dome, turning the region into a huge sauna. That heat dome is like a hot air bubble covering an area and trapping heat like a lid on a pot, keeping cooler air and rainstorms out. This makes everything underneath get hotter and hotter, with no way to cool down. Officials warned that the heat index is expected to reach 110 to 115 degrees in parts of Missouri, Illinois, Iowa, and Indiana . Major Midwest cities like Kansas City, Des Moines, and Chicago are all under heat watches or warnings through the night, as meteorologists have said the air will stay thick and damp even after the sun sets. Justin Glisan, an Iowa State University climatologist, said: 'The phenomenon as being thick and oppressive, particularly if there is no wind, like being fully clothed in a sauna or steam room.' According to AccuWeather, more than 200 million people across 37 states will experience the triple-digit heat wave by Friday. Officials have issued extreme heat alerts for the Mississippi Valley, while the entire Chicago area is under an extreme heat watch through Thursday. This week, humidity from cornfields has intensified the already severe heat dome, extending from Texas to the Great Lakes. Over 100 cities are expected to challenge overnight heat records, raising serious risks for heat stress, especially where there is no air conditioning. The timing of this summer scorcher is no coincidence, as it coincides with the blossoming period of the corn plant. In Iowa alone, corn is planted across millions of acres. On Thursday and Friday, the heat dome will expand further east, covering the regions that rarely see this level of heat and humidity, especially New England and parts of the Northeast. In Maine, where summer temperature usually stay in the 70s or low 80s, it could reach the 90s by Friday. Portland is most likely to hit 94 degrees, but humidity will make it feels live over 100 Fahrenheit. Boston will also get very hot, with temperatures near 100 when you factor in the moisture in the air. Even cities near the coast would not be safe from the heat. Meteorologists say this heat will be short but strong. It's not like the long-lasting heat in the Plains, but it still could cause problems. The heat comes from moisture moving east, mostly from the Midwest's corn fields, which release a lot of water vapor into the air. This makes the air feel even hotter. New York City will see some of its hottest days this month with highs in the mid-90s and nights staying warm near 80 degrees. Many cities in the South and Midwest will also stay hot at night, giving little relief from the heat. Places like Little Rock and Jackson could see nighttime lows only reach the 80s. Corn in states like Iowa, Illinois, and Indiana is at a stage where it releases lots of moisture, which adds to the humidity spreading east. Washington, DC, will hit 97 degrees Friday, but it will feel hotter, between 105 and 110 because of the extra humidity coming from the South and Midwest. According to AccuWeather, Dallas will reach over 100 degrees, and Houston and San Antonio will stay in the triple digits. Forecasters say the Central Plains, including Kansas and Nebraska, could shift from humid to dangerously dry by mid-August. The heat will worsen with dry ground, pushing temperatures from the upper 90s to 100, with some areas possibly hitting 110 degrees Fahrenheit. AccuWeather Senior Meteorologist Chad Merrill said: 'The bottom line is that this has the look of a long-lasting heat wave with limited rainfall.' The Corn Belt is not in a drought right now, but that could change. As the ground dries under this heat dome, less water will evaporate to cool the air, and actual temperatures will rise even more. Some areas could climb to 110 degrees or more. Even tropical moisture from the Gulf would not help much. High pressure is blocking it from moving north in most places, and whatever rain does fall likely would not be enough to cut the heat.
