Is One Type of Water Healthier Than Another? Here’s What Experts Say

SUNDAY, July 6, 2025 (HealthDay News) — Alkaline. Electrolyte. Flavored. Walk down the beverage aisle and you’ll find all kinds of waters promising extra health perks. But are these fancy waters really better for you?

Not really, Tufts University experts say.

“There’s no physiological basis that there’s some metabolic benefit to these specialty waters over just regular, plain old water,” said Roger Fielding, a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts in Boston.

For most people, Fielding said the best thing to do is simply drink more fluids — especially since many people walk around mildly dehydrated.

“If you have a preference for a beverage and that’s going to make you drink more and you’ll be more attentive to rehydrating with that beverage, and you have the resources to purchase that beverage, well have at it,” Fielding said in a news release.

“Just like with sweetened beverages to an extent, if you’re not in excess, you’re more likely to rehydrate because a beverage is sweetened or flavored,” he added.

Still, Fielding urged people to check nutrition labels — yes, even on water. Waters labeled with “added electrolytes” may contain added sodium.

Adults should aim for less than 2 grams of sodium a day.

“If someone consumes large amounts of water with high levels of sodium, they could elevate their risk of hypertension and other negative cardiovascular outcomes associated with excess salt intake,” Fielding said. “But most of these beverages that provide those kinds of electrolytes, they’re fairly dilute.”

Even for people who sweat a lot — like endurance athletes or hot yoga devotees — he said it’s “very difficult to induce an electrolyte deficiency.”

Electrolytes, such as sodium and potassium, help your body with important tasks. They’re found in food and drinks and are also made naturally by the body.

“The electrolyte concentrations inside our cells, and also in the fluids that are outside our cells, like the blood, for example, are very tightly controlled and regulated,” Fielding said. 

“That’s because they have an impact on how our muscles function, how our kidneys work, and how our hearts sort of beat 72 times every minute,” he explained. “So, increasing the electrolyte concentrations by consuming a beverage is not going to influence the overall electrolyte concentrations in our bodies.”

Some waters are labeled “alkaline,” suggesting they help balance the body’s pH (acid-to-alkaline) levels. But Dr. Bess Dawson-Hughes, another Tufts scientist and professor of medicine, said there’s no proof that young, healthy people benefit from drinking them.

“We don’t have direct evidence that shows a benefit from alkaline water interventions compared with non-alkaline water interventions,” Dawson-Hughes said. 

“But it would be logical if, as an older person, you have an acid-producing diet and it’s costing you bone and muscle that you might do well to get alkali any way you could get it,” she added.

However, she said older adults may benefit if they have a diet high in acid-forming foods like proteins and grains.

“When we’re young, our kidneys are functional enough to make needed adjustments to get us pH balanced, by dumping extra hydrogen ions,” Dawson-Hughes said. 

“When we age, our kidneys decline in that capacity. If the kidney can’t get rid of excess acid, guess what happens next?” she said. “Bone is resorbed or lost because bone is, in essence, an alkali reservoir.”

Eating more fruits and vegetables — alkali foods — can help, and alkaline water might play a small role too, though more research is needed.

Fielding said enhanced waters may help older adults who avoid drinking due to bladder problems or simply forget.

“For caregivers and providers, it’s important to remind the aging population that staying hydrated is important,” she said. “We need to encourage people to consume an adequate amount of liquid, because they might not know to do it on their own.”

But at the end of the day, you don’t need to spend extra money to stay hydrated.

“The best fluid replacement that you can probably drink to prevent becoming dehydrated is water,” Fielding said. “Water trumps everything, except in maybe some very extreme circumstances.”

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https://www.usnews.com/news/health-news/articles/2025-07-05/is-one-type-of-water-healthier-than-another-heres-what-experts-say

Maryland Attorney General joins 17 states in defending nationwide drinking water standards

BALTIMORE — Maryland Attorney General Anthony Brown joined a coalition of 17 states to file an appeal in defense of the U.S. Environmental Protection Agency’s (EPA) Safe Drinking Water Act, which established the nation’s first drinking water standards limiting the amount of PFAS – or forever chemicals. 

The measure created nationwide protections against six types of polyfluoroalkyl (PFAS) chemicals and set standards for four other PFAS chemicals. 

Under the Safe Drinking Water Act, public water systems across the country are required to test drinking water for contaminants and treat the water if necessary. 

In the appeal, state leaders argued that the rule would improve public health if it is upheld. 

Maryland AG Brown joined attorneys general from Arizona, California, Colorado, Connecticut, Delaware, the District of Columbia, Hawai’i, Illinois, Massachusetts, Michigan, Minnesota, New Jersey, New York, North Carolina, Oregon, Rhode Island and Wisconsin in the appeal.

What is PFAS? 

PFAS chemicals have been used in many settings, including in airports and fire departments, and in products like car seats and non-stick cookware. Since they don’t break down, the chemicals pollute the environment, earning them the name “forever chemicals.” 

PFAS chemicals are toxic to humans and animals and even minimal exposure can impact health. The chemicals often enter and accumulate in our bodies through drinking water. 

According to CBS News, research found that PFAS chemicals are present in the blood of almost all Americans. 

“PFAS are dangerous chemicals that cause serious health risks. This rule permits water systems across the country, including here in Maryland, to regulate and treat these harmful substances,” said Attorney General Brown. “By making our drinking water cleaner, this policy safeguards the health of not only our generation but also our children and grandchildren. Our Office will fight to protect Marylanders’ access to safe and healthy drinking water.” 

PFAS chemicals in Maryland 

This is not the first time AG Brown has taken action against forever chemicals. 

In December 2024, the attorney general sued manufacturing giant W.L. Gore & Associates, claiming they knowingly polluted the air and water with PFAS chemicals. The company is based in Cecil County. 

According to CBS News, PFAS chemicals are sometimes used as a thin layer of waterproof material in clothes, and can be found within W.L. Gore & Associates’ “Gore-tex jackets.”

The attorney general’s lawsuit alleged that the company released forever chemicals for more than half a century, contaminating drinking water and natural resources, including soil, plants and animal life. 

In 2023, CBS News reported that the company debuted a technology that uses non-fluorinated materials, and said it plans to “transition the vast majority of its consumer portfolio by end of 2025.”

The attorney general’s lawsuit asks W.L. Gore & Associates to pay all costs related to the investigation and cleanup of the chemicals. 

In 2024, at least 10 Harford County schools were found to be contaminated with PFAS. School officials said the water was not safe to drink, so bottled water was provided.

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https://www.cbsnews.com/baltimore/news/maryland-pfas-forever-chemicals-water-quality-health/?intcid=CNM-00-10abd1h

The best refrigerators with water filters: Reducing contaminants and understanding PFAS (forever chemicals)

If you’re making informed choices about the quality of the food you eat, you might also make informed choices about the quality of the water you drink. A new study by the U.S. Geological Survey estimates that “forever chemicals” can be found in 45% of tap water in the United States. 

The EPA warns the substances, also known as per- and polyfluorinated substances (PFAS) are “long-lasting chemicals, components of which break down very slowly over time” and may be linked to harmful health effects in humans.

One way to help protect yourself from contaminants and reduce your overall exposure to unwanted substances? Experts say drink filtered water. (Some bottled water has been found to contain PFAS.) And while experts say Brita filters can remove some contaminants, you can also get filtered water and ice from your refrigerator. The CBS Essentials shopping experts have found the best refrigerators with water filters that might help reduce your intake of certain contaminants. 

What are PFAS (forever chemicals)?

PFAS have been linked to a range of health problems, including certain forms of cancer. You may be able to reduce the amount of PFAS in your home’s water with a water filter. But not all water filters are the same. 

“In general, refrigerator filters are designed to remove sediments, chlorine, lead and other common contaminants and not specifically PFAS compounds,” says Dr. Andrew Lazur, a University of Maryland water quality specialist. “That said, since some refrigerator filters use activated carbon, they can reduce some PFAS compounds, but may not achieve EPA or state-recommended concentrations.”

In other words, Lazur says that some fridge filters can reduce forever chemicals, but exactly how much may vary from product to product.

“Consumers should ask about the water filters used in the refrigerators, and inquire specifically about what contaminants are reduced, and by what percent,” Lazur told CBS Essentials. “Also asking about filter replacement schedule and cost may help in decision making.”

We also have a guide for standalone water filters here.

Best refrigerators with water filters that reduce contaminants

The National Sanitation Foundation (NSF) examined several popular water filters, including water filters in refrigerators, and discovered that an LG water filter was able to remove 53 known contaminants in drinking water that are dangerous to human health.

While these refrigerators with water filters have not been proven to remove PFAS, they can help remove man-made and naturally occurring contaminants, including chlorine, pesticides, herbicides, insecticides and other impurities.

All of these top-rated fridges have a four-star rating or higher and include many positive customer reviews about the device’s water filtration.

LG smart Max refrigerator with dual ice makers

lg-max.jpg
LG

Your refrigerator should dispense clean water you can count on. This LG smart fridge is equipped with LG’s top-rated water filter, the same refrigerator water filter that the NSF says can remove 53 known hazardous contaminants. According to LG, the filter can remove pesticides, chemicals and detergents. The filter is certified by NSF International to meet industry-leading filtration standards. It should be replaced every six months.

This 4.2-star-rated refrigerator offers 26 cubic feet of evenly cooling tech to keep food fresh. Use the LG ThinQ app to adjust your refrigerator temp settings or troubleshoot your device.

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https://www.cbsnews.com/miami/essentials/best-refrigerators-with-water-filters-reducing-forever-chemicals/?intcid=CNM-00-10abd1h

Sacramento water treatment plant to get multi-million-dollar makeover

Each year, Sacramento needs about a million more gallons of water per day to meet growing demand. Soon, the city’s water treatment plants will have a tough time keeping up. 

A new multi-million dollar plan aims to modernize the system, ensuring Sacramento’s future is flush with water. 

“It’s not something everyone gets excited about but it’s really, really important,” said. 

The city unveiled a plan called Water+. It will double the daily capacity of the existing Sacramento River water treatment plant, just off Interstate 5 and Richards Boulevard. 

“It’s improving our water system to be more resilient and more able to adapt to some of the modern challenges that we experience,” said. Continue watchingMiwok tribe purchases former Macy’s building in downtown Sacramentoafter the ad

The plant dates back to 1921 and some of the aging infrastructure needs to be replaced. 

The city said that modernizing the facility will help comply with environmental regulations and provide reliable water that filters out more river contaminants. 

“We’ve got things like cyano algae toxic blooms that kind of pop up from time to time that can affect our ability to manage drinking water,” said. 

But there’s no way for the current plant to expand its property size, so said “we need to be able to figure out how we can most efficiently use the space that we do have.” 

That means some of the historical landmark buildings will be impacted. The plan also calls for adding an additional water intake pumping station on the Sacramento River just upstream from the existing one near Matsui Park. 

That will help provide more water for future city growth. 

“This project is being phased out over long term so that we can be able to address the water needs of that growth,” said. 

So far, there’s no estimate on how much the project will cost. The city’s utility department is expected to release an environmental impact report this spring.

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https://www.cbsnews.com/sacramento/news/sacramento-water-treatment-plant-to-get-multi-million-dollar-makeover/?intcid=CNM-00-10abd1h

Beachgoers urged to avoid water at LA County beaches due to rainfall contaminants

Beachgoers in Los Angeles County are being urged to avoid any contact with the water, particularly near storm drains, creeks, and rivers.

The Ocean Quality Rain Advisory is expected to remain in place for all county beaches until 8 a.m. Thursday.

“Ocean and bay recreational waters, especially near discharging storm drains, creeks and rivers can be contaminated with bacteria, chemicals, debris, trash, and other public health hazards from city streets and mountain areas after a rain fall,” the advisory warned. 

Public health officials caution that anyone who enters the water in these areas could risk illness, and the advisory may be extended if rainfall continues.

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https://www.cbsnews.com/losangeles/news/beachgoers-urged-to-avoid-water-at-la-county-beaches-due-to-rainfall-contaminants/?intcid=CNM-00-10abd1h

Michigan officials say there are “significant deficiencies” in Wyandotte’s water system

The Michigan Department of Environment, Great Lakes and Energy has issued a report that there are “significant deficiencies” in the management of Wyandotte’s water system. 

But the city says the water is safe, adding “it consistently meets or exceeds all state and federal water quality standards.” 

“There is no known current risk to public health from the City’s drinking water, and we are fully committed to maintaining that record,” the city said on its website

The respective statements spin out of a notice that Michigan EGLE issued April 30, citing “significant deficiencies” in the areas of treatment, distribution system, finished water storage and management/operations. The letter was also sent to the Wayne County Health Department. 

“The most significant observations during the Survey are the need for adequate 
investment in capital improvement projects, completion of maintenance activities, and 
adequate investment in staffing,” EGLE said in its letter. “There are several indications the City is not keeping up with capital investments, especially in the distribution system and future operational and maintenance needs may overwhelm the available budget and resources.”  

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The four matters listed as significant deficiencies were: 

  • Failure to keep up with an inspection schedule for backflow prevention and cross-connections. 
  • Damage to the vents at one reservoir. 
  • Assorted debris, such as tennis balls and beverage containers, was found at another reservoir. 
  • A water treatment process that didn’t include a specified method of mixing the treatment chemical into the raw water. 

The city was given 120 days to either correct the significant deficiencies noted or submit a “corrective action plan” that EGLE will review. 

There were also other matters noted as deficiencies, such as an inspection report that showed zebra mussels found near an entrance to a water intake pipe, and routine maintenance schedules, such as hydrant flushing that was not implemented “due to inadequate staffing.” 

In addition, the city of Wyandotte has not included fluoride treatment for several years. “If fluoride treatment is not continued, the appropriate local procedures need to be followed,” the letter says. “It is imperative for the water supply to notify the public so residents can make informed decisions about their oral health.” 

On that detail, the city has replied, “Fluoridation of drinking water is not required by law. The City discontinued fluoride treatment in 2015 during a treatment plant rehabilitation project. Fluoride levels are monitored and disclosed in the City’s annual Consumer Confidence Reports, and residents are encouraged to consult with their dental professionals about supplemental fluoride needs.” 

Wyandotte officials say after the April report was issued, the city’s Municipal Services took steps toward “actively addressing all recommendations.” This includes a series of repairs at the reservoirs and evaluation of its filtration method. 

In the meantime, the EGLE staff noted that during the three years before its report was issued, the city had taken a number of steps to address water facility operations and improvements. 

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https://www.cbsnews.com/detroit/news/egle-wyandotte-municipal-water-system/?intcid=CNM-00-10abd1h

Antarctica’s slow collapse caught on camera—and it’s accelerating

Researchers from the University of Copenhagen have gained unique insight into the mechanisms behind the collapse of Antarctic ice shelves, which are crucial for sea level rise in the Northern Hemisphere. The discovery of old aerial photos has provided an unparalleled dataset that can improve predictions of sea level rise and how we should prioritise coastal protection and other forms of climate adaptation.

On November 28, 1966, an American aeroplane flies over the Antarctic Peninsula just south of the southernmost tip of Chile.

On board is a photographer, probably from the US Navy, whose job is to map the Antarctic landscape. But it turns out that the photographer is also documenting a very special situation that is in progress. He shoots an aerial photo of the Wordie Ice Shelf, which, 30 years later, has almost vanished after a total collapse.

The consequence of this collapse was that the ‘plug’ that held large amounts of glacier ice broke off, leaving the ice sheet floating freely into the sea.

Fortunately, Wordie is a relatively small ice shelf and the sea level rise it has caused can be measured in millimeters. But there are much larger ice shelves in Antarctica, which, like Wordie, could collapse due to climate change. Just the two largest ice shelves, Ronne and Ross, are believed to hold enough ice to account for sea level rises of up to five meters.

If, in this context, we think that Antarctica is far away, we need to understand that the melting of ice in the Southern Hemisphere will cause sea levels to rise in places like Denmark in the Northern Hemisphere, due to the effects of gravity. A new research study provides insights that can help identify signs of incipient collapse in these ice shelves and assess the stage of collapse.

The photo of Wordie from 28 November 1966 — the first in a long series of images that continually document the collapse of the Wordie Ice Shelf through the 1960s — has become a valuable first data point in a study of the ice shelf collapse recently completed by researchers at the University of Copenhagen.

In their paper, now published in Nature Communications, they present a unique dataset based on the vast archives of old aerial images combined with modern satellite observations, which, for the first time, shows the collapse of an ice shelf as a constant evolution in a long time series. A critical insight that can be used to improve scientists’ understanding of ice shelves and the mechanisms behind their collapse.

“We have identified several signs of incipient ice shelf collapse that we expect will be observed in other ice shelves, but perhaps more importantly, the dataset has given us a multitude of pinning points that can reveal how far advanced a collapse is. It’s a completely new tool that we can use to do reality checks on ice shelves that are at risk of collapsing or already in the process of collapsing,” says Postdoc Mads Dømgaard from the Department of Geosciences and Natural Resource Management, who is lead author of the study.

According to the researchers, this knowledge will enhance computer models of sea level rise and lead to more accurate predictions of when the water will rise, allowing for prioritization of investments in climate change adaptation in the most effective way.

Warmer seawater and melting under the ice were most conclusive

The hundreds of historical aerial photos were analyzed using a technique known as structure-from-motion photogrammetry. The method has enabled scientists to accurately reconstruct ice thickness, as well as its extent, surface structure and flow velocity, dating back to the 1960s.

In this way, the researchers analyzed the collapse of Wordie and learned more about the factors involved. It was previously assumed that a warmer atmosphere was the primary factor leading to the collapse, and, similarly, that the formation of meltwater lakes on the ice surface had also played a part. The new study has disproved both assumptions.

Instead, the researchers highlight melting under the ice where the sea and ice meet as definitive factors.

“Our findings show that the primary driver of Wordie’s collapse is rising sea temperatures, which have generated the melting beneath the floating ice shelf,” Mads Dømgaard says.

Collapse is tougher than we thought – like it or not

Furthermore, the study’s findings have already altered the foundation of scientists’ knowledge about ice shelf collapse. According to co-author Anders Anker Bjørk, the new data advances our understanding of how and at what speed these collapses occur.

“The tentative conclusion from our findings is that ice shelf collapse may be slower than we thought. This means that the risk of a very rapid development of violent sea level rise from melting in Antarctica is slightly lower, based on knowledge from studies like this one,” says Anders Anker Bjørk, Assistant Professor at the Department of Geosciences and Natural Resource Management.

But there is also a flip side to this, he explains:

“It was already a supertanker that needed to be turned to stall the melting of ice in Antarctica, but our data shows a collapse process that is even more protracted than previously assumed. And this longer process will make it harder to reverse the trend once it has started. This is an unambiguous signal to prioritize halting greenhouse gas emissions now rather than sometime in the future,” Anders Anker Bjørk says.

Facts: ice shelves and sea level rise

Ice shelves, like Wordie, act as a kind of brake on glaciers flowing from the ice sheet towards the sea. When an ice shelf vanishes, the glaciers lose this support and can begin to float and melt more rapidly.

As the ice mass of ice shelves is already partially or wholly in the sea, their direct contribution to sea level rise is limited. On the other hand, the glacier ice they retain is on land and, therefore, every cubic meter affects the water level of the world’s oceans.

Although Antarctica is far away, areas like Denmark are being affected significantly by sea level rise caused by ice shelf collapses resulting from gravitational forces. Before Antarctica melts, its ice mass helps pull sea waters southwards. When the ice has melted into the sea, the gravitational field has changed, causing the oceans to the north to rise proportionally more.

Facts: How dusty old photos became important data

In the study, the researchers used images from multiple overflights of Wordie, shot between 1966 and 1969.

In analyzing the historical aerial photos, the researchers employed the structure-from-motion photogrammetry method, which utilizes overlapping photos to calculate accurate three-dimensional models of landscapes or objects.

By analyzing differences in perspective between the photos, it’s possible to measure heights and distances with high accuracy. This allows tracing how the ice surface, thickness and velocity have changed over time.

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https://www.sciencedaily.com/releases/2025/07/250706230305.htm

Scientists thought the Arctic was sealed in ice — they were wrong

By analyzing ancient ocean seafloor sediments and running detailed climate simulations, the research team found no evidence for the presence of a thick ice shelf. Instead, this study paints a picture of an Arctic that, despite being cold and icy, still had open water areas that allowed for biological activity and ocean circulation. Credit: Morven Muilwijk

For years, scientists have debated whether a giant thick ice shelf once covered the entire Arctic Ocean during the coldest ice ages. Now a new study published in Science Advances, challenges this idea as the research team found no evidence for the presence of a massive ~1km ice shelf. Instead, the Arctic Ocean appears to have been covered by seasonal sea ice — leaving open water and life-sustaining conditions even during the harshest periods of cold periods during the last 750,000 years. This discovery gives insights crucial for our understanding of how the Arctic has responded to climate change in the past — and how it might behave in the future.

Tiny traces of life in ancient mud

Led by the European Research Council Synergy Grant project Into the Blue — i2B, the research team studied sediment cores collected from the seafloor of the central Nordic Seas and Yermak Plateau, north of Svalbard. These cores hold tiny chemical fingerprints from algae that lived in the ocean long ago. Some of these algae only grow in open water, while others thrive under seasonal sea ice that forms and melts each year.

“Our sediment cores show that marine life was active even during the coldest times,” said Jochen Knies, lead author of the study, based at UiT The Arctic University of Norway and co-lead of the Into The Blue — i2B project. “That tells us there must have been light and open water at the surface. You wouldn’t see that if the entire Arctic was locked under a kilometre-thick slab of ice.”

One of the key indicators the team looked for was a molecule called IP25, which is produced by algae that live in seasonal sea ice. Its regular appearance in the sediments shows that sea ice came and went with the seasons, rather than staying frozen solid all year round.

Simulating ancient Arctic climates

To test the findings based on the geological records, the research team used the AWI Earth System Model — a high-resolution computer model — to simulate Arctic conditions during two especially cold periods: the Last Glacial Maximum around 21,000 years ago, and a deeper freeze about 140,000 years ago when large ice sheets covered a lot of the Arctic.

“The models support what we found in the sediments,” said Knies. “Even during these extreme glaciations, warm Atlantic water still flowed into the Arctic gateway. This helped keep some parts of the ocean from freezing over completely.”

The models also showed that the ice wasn’t static. Instead, it shifted with the seasons, creating openings in the ice where light could reach the water — and where life could continue to thrive. This research not only reshapes our view of past Arctic climates but also has implications for future climate predictions. Understanding how sea ice and ocean circulation responded to past climate extremes can improve models that project future changes in a warming world.

“These reconstructions help us understand what’s possible — and what’s not — when it comes to ice cover and ocean dynamics,” said Gerrit Lohmann, co-author of this study, based at Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and co-lead of Into The Blue — i2B. “That matters when trying to anticipate how ice sheets and sea ice might behave in the future.”

Re-thinking the giant ice shelf theory

Some scientists have argued that features on the Arctic seafloor suggest that a huge, grounded ice shelf once covered the entire ocean. But this new study offers another explanation.

“There may have been short-lived ice shelves in some parts of the Arctic during especially severe cold phases,” said Knies. “But we don’t see any sign of a single, massive ice shelf that covered everything for thousands of years.”

One possible exception could have occurred about 650,000 years ago, when biological activity in the sediment record dropped sharply. But even then, the evidence points to a temporary event, not a long-lasting frozen lid over the Arctic.

Understanding the Arctic’s future

The study sheds new light on how the Arctic has behaved under extreme conditions in the past. This matters because the Arctic is changing rapidly today. Knowing how sea ice and ocean circulation responded to past climate shifts helps scientists understand what might lie ahead.

“These past patterns help us understand what’s possible in future scenarios,” said Knies. “We need to know how the Arctic behaves under stress — and what tipping points to watch for — as the Arctic responds to a warming world.”

The full paper, “Seasonal sea ice characterized the glacial Arctic-Atlantic gateway over the past 750,000 years,” is available in Science Advances.

This research is part of the European Research Council Synergy Grant project Into the Blue — i2B and the Research Council of Norway Centre of Excellence, iC3: Centre for ice, Cryosphere, Carbon, and Climate.

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https://www.sciencedaily.com/releases/2025/07/250704235554.htm

Melting glaciers are awakening Earth’s most dangerous volcanoes

Scientists have discovered that melting glaciers could unleash powerful volcanic eruptions by removing the weight that keeps magma trapped deep underground. Antarctica may hold hundreds of these explosive time bombs. Credit: Shutterstock

Melting glaciers may be silently setting the stage for more explosive and frequent volcanic eruptions in the future, according to research on six volcanoes in the Chilean Andes.

Presented today (July 8) at the Goldschmidt Conference in Prague, the study suggests that hundreds of dormant subglacial volcanoes worldwide – particularly in Antarctica – could become more active as climate change accelerates glacier retreat.

The link between retreating glaciers and increased volcanic activity has been known in Iceland since the 1970s, but this is one of the first studies to explore the phenomenon in continental volcanic systems. The findings could help scientists better understand and predict volcanic activity in glacier-covered regions.

Researchers from the University of Wisconsin-Madison, USA, used argon dating and crystal analysis across six volcanoes in southern Chile, including the now dormant Mocho-Choshuenco volcano, to investigate how the Patagonian Ice Sheet’s advance and retreat influenced past volcanic behaviour. The work is in collaboration with researchers from Lehigh University, University of California Los Angeles, and Dickinson College.

By precisely dating previous eruptions and analysing crystals in erupted rocks, the team tracked how the weight and pressure of glacial ice alter the characteristics of magma underground.

They found that during the peak of the last ice age (around 26,000-18,000 years ago), thick ice cover suppressed the volume of eruptions and allowed a large reservoir of silica-rich magma to accumulate 10-15 km below the surface.

As the ice sheet melted rapidly at the end of the last ice age, the sudden loss of weight caused the crust to relax and gasses in the magma to expand. This buildup of pressure triggered explosive volcanic eruptions from the deep reservoir, causing the volcano to form.

Pablo Moreno-Yaeger from the University of Wisconsin-Madison, USA, is presenting the research at the Goldschmidt Conference. He said: “Glaciers tend to suppress the volume of eruptions from the volcanoes beneath them. But as glaciers retreat due to climate change, our findings suggest these volcanoes go on to erupt more frequently and more explosively. The key requirement for increased explosivity is initially having a very thick glacial coverage over a magma chamber, and the trigger point is when these glaciers start to retreat, releasing pressure – which is currently happening in places like Antarctica.

“Our study suggests this phenomenon isn’t limited to Iceland, where increased volcanicity has been observed, but could also occur in Antarctica. Other continental regions, like parts of North America, New Zealand and Russia, also now warrant closer scientific attention.”

While the volcanic response to glacial melting is almost instant in geological terms, the process of changes in the magma system is gradual and occurs over centuries, giving some time for monitoring and early warning.

The researchers also note that increased volcanic activity could have global climate impacts. In the short term, eruptions release aerosol (tiny particles in gases) that can temporarily cool the planet. This was seen after the 1991 eruption of Mount Pinatubo in the Philippines, which reduced global temperatures by approximately 0.5 degrees C. But with multiple eruptions, the effects reverse.

“Over time the cumulative effect of multiple eruptions can contribute to long-term global warming because of a buildup of greenhouse gases,” said Moreno-Yaeger. “This creates a positive feedback loop, where melting glaciers trigger eruptions, and the eruptions in turn could contribute to further warming and melting.”

The research was funded by the National Science Foundation as part of a grant led by Professor Brad Singer at UW-Madison, and is due to be published in a peer-reviewed journal later this year.

The Goldschmidt Conference is the world’s foremost geochemistry conference. It is a joint congress of the European Association of Geochemistry and the Geochemical Society (US), and over 4000 delegates attend. It takes place in Prague, Czech Republic, from July 6-11 2025.

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https://www.sciencedaily.com/releases/2025/07/250708045654.htm

Why Milton’s ‘Reverse Surge’ Sucked Water Away From Flood-Fearing Tampa

In the days before Hurricane Milton hit Florida, forecasters worried it could send as much as 15 feet of water rushing onto the heavily populated shores of Tampa Bay

By Associated Press

U.S. News & World Report

Chris Urso

Chris Urso

Debris along Commonwealth Drive clogs the roadway after Hurricane Milton made landfall nearby Thursday, Oct. 10, 2024 in Siesta Key, Fla. (Chris Urso/Tampa Bay Times via AP)

In the days before Hurricane Milton hit Florida, forecasters were worried it could send as much as 15 feet (4.5 meters) of water rushing onto the heavily populated shores of Tampa Bay.

Instead, several feet of water temporarily drained away.

Why? “Reverse storm surge” is a familiar, if sometimes unremarked-upon, function of how hurricane winds move seawater as the storms hit land — in fact, it has happened in Tampa Bay before.

In the Northern Hemisphere, tropical storm winds blow counterclockwise. At landfall, the spinning wind pushes water onshore on one end of the eye and offshore on the other. Picture drawing a circle that crosses a line, and see how the pencil moves toward the line at one point and away at another.

The most pronounced water movement is under the strong winds of the eyewall, explains Brian McNoldy, a University of Miami senior researcher on tropical storms.

Milton’s path toward the central part of Florida’s west coast was clear for days, raising the possibility that Tampa Bay could bear the brunt of the surge. But it is always tricky to predict exactly where landfall will happen — and when, which can be important because a daily high tide can accentuate a surge.

To be sure, hazardous wind, rain and some degree of surge can happen far from the center. But the exact location of landfall makes a big difference in where a surge peaks, McNoldy said. Same goes for a reverse, or “negative,” surge.

Ultimately, the center of east-northeastward-moving Milton made landfall Wednesday night at Siesta Key, near Sarasota. It is about 70 miles (112 kilometers) south of the city of Tampa.

That meant fierce onshore winds caused a storm surge south of Siesta Key. The National Hurricane Center said Thursday that preliminary data shows water rose 5 to 10 feet (1.5 to 3 meters) above ground between Siesta Key and Fort Myers Beach.

Meanwhile, the water level abruptly dropped about 5 feet at a National Oceanic and Atmosphere Administration gauge near Tampa late Wednesday night.

Hurricane Irma caused a similar effect in 2017. So did Ian in 2022, when people strode out to see what was normally the sea bottom.

In any storm, “that’s an extremely bad idea,” McNoldy says. “Because that water is coming back.”

Indeed, water levels returned to normal Thursday morning.

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