2022 Pacific volcano eruption made a deep dive into Alaska

University of Alaska Fairbanks

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Atmospheric waves from a massive 2022 South Pacific volcanic eruption created seismic waves that penetrated Earth to at least 5 kilometers in Alaska, creating an opportunity to employ an unusual method of peering into the state’s deep subsurface.

Ken Macpherson, a scientist at the University of Alaska Fairbanks Geophysical Institute, and other researchers analyzed the coupling of atmospheric pressure waves with the ground to determine the speed at which seismic waves travel through Alaska’s upper crust. 

Subsurface material properties such as hardness, which controls seismic velocity, can be inferred through examination of the relative strength of incoming pressure waves and the resulting seismic waves.

Think of it like blowing onto the surface of a bowl of Jell-O versus blowing on a pan of brownie batter with equal force: You could see the Jell-O shake, but the brownies would not move much because the material is stiffer.

“Hunga-Tonga’s pressure waves have provided us much more information about how seismic waves propagate in Alaska,” Macpherson said.

Macpherson's research of seismic velocity to depths of 30 meters, 2 kilometers and 5 kilometers was published July 8 in Seismica.

The eruption

The explosive eruption of Hunga Tonga–Hunga Ha’apai volcano, in the Kingdom of Tonga and about 6,000 miles from Alaska, occurred on Jan. 15, 2022. The eruption’s atmospheric waves were the largest known from a volcano since the 1883 Krakatau eruption.

“Hunga Tonga was an unprecedented explosion in the instrument age,” said Macpherson, who is with the institute’s Wilson Alaska Technical Center. “Those pressure waves shook Alaska, 6,000 miles away, which I just think is so remarkable. And many of those were long-period waves and consequently shook Earth to a great depth.”

A network of 150 co-located barometers, infrasound sensors and seismometers in Alaska recorded the eruption’s data used in Macpherson’s research.

Gaining information via air-to-ground coupling at a depth of 5 kilometers is uncommon. That’s because seismic waves produced through coupling usually have a shorter wavelength — unless the power source is something really, really big.

“Because the Hunga explosion was so enormous, the pressure waves that traveled the long distance to Alaska were still powerful enough to shake the Earth, and were therefore ideal for a coupling study,” Macpherson said.

Air-to-ground coupling

How does an atmospheric pressure wave shake the ground? And how can it rattle the ground 5 kilometers below the surface?

Powerful pressure waves from a volcanic eruption or explosion create rapid changes in air pressure as they travel through the atmosphere. When these pressure waves contact the ground, they push and pull on the surface in a process called air-to-ground coupling that transfers energy into Earth's interior. 

The energy transfers through a process described as Newton’s Second Law, which states that an applied force causes particles to move by overpowering their inertia. That particle motion creates seismic waves containing mechanical energy in two forms — kinetic energy from the moving particles and elastic energy from the crust’s temporary deformation as the wave passes through.

Waves of information

The velocity research can be an additional tool for seismic hazard analysis because wave speed affects the level of ground motion. 

“If a propagating wave is in deep material and going fast but suddenly hits a softer material, the conservation of energy says, ‘Well, I’m going slower, but I still have the same energy,’” Macpherson said. “That means amplitudes get bigger, causing stronger shaking.”

“Just knowing those upper crustal velocities is good for seismic hazard analysis,” he said. “It’s [also] good for network operators like the Alaska Earthquake Center because they can accurately apply the crustal velocity beneath a particular seismic station to potentially increase earthquake location accuracy.”

Macpherson’s work also can be particularly helpful in tomography, a technique seismologists use to create three-dimensional images of Earth’s interior by analyzing how seismic waves travel through different materials. Tomography reveals variations in properties such as density or velocity, helping scientists map the deep subsurface.

“To do tomography properly you have to do what’s called a crustal correction because velocities in the upper crust are so much different from those deeper velocities that you’re trying to get at,” he said. “If you know something about the crust, you can apply a correction that improves tomography for tens to hundreds of kilometers.”

The research paper’s co-authors include research professor David Fee, postdoctoral researcher Stefan Awender, assistant professor Bryant Chow and seismo-acoustic researchers Juliann Colwell and Sam Delamere, all with the UAF Geophysical Institute’s Wilson Alaska Technical Center. Matthew Haney of the U.S. Geological Survey is also a co-author.

The Nuclear Arms Control Technology Program at the U.S. Defense Threat Reduction Agency financially supported the research.

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CONTACTS:

• Ken Macpherson, University of Alaska Fairbanks Geophysical Institute, kamacpherson@alaska.edu

• Rod Boyce, University of Alaska Fairbanks Geophysical Institute, 907-474-7185, rcboyce@alaska.edu

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Journal

Seismica

DOI

10.26443/seismica.v4i2.1557 

Article Title

Alaska Upper Crustal Velocities Revealed by Air-to-Ground Coupled Waves From the 2022 Hunga Tonga-Hunga Ha’apai Eruption

 

‘Cyborg jellyfish’ could aid in deep-sea research, inspire next-gen underwater vehicles

University of Colorado at Boulder

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University of Colorado Boulder engineer Nicole Xu stands behind the main jellyfish tank in her lab. (Credit: Glenn Asakawa)

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Credit: Glenn Asakawa/University of Colorado Boulder

In a towering aquarium in a darkened laboratory, moon jellyfish (Aurelia aurita) hover as if floating in space.

The glow of neon lights illuminates their translucent, bell-shaped bodies as they expand and contract rhythmically, their graceful tentacles flowing in wavelike patterns.

CU Boulder engineer Nicole Xu watches them with fondness. Xu, an assistant professor in the Paul M. Rady Department of Mechanical Engineering, first became fascinated with moon jellies more than a decade ago because of their extraordinary swimming abilities. Today, Xu has developed a way to harness their efficiency and ease at moving through the water in ways that could make some types of aquatic research much easier.

She fits the jellies with microelectronic devices that activate key swimming muscles, enabling researchers to steer them toward remote ocean areas that are hard to access in any other way. Eventually, she plans to add sensors to the devices that can gather critical data on temperature, pH and other environmental characteristics.  

“Think of our device like a pacemaker on the heart,” Xu said. “We're stimulating the swim muscle by causing contractions and turning the animals toward a certain direction.”

Going where humans can’t go

Nicole Xu reaches her hand into the tank and touches one of the moon jellyfish. (Credit: Glenn Asakawa)

As climate change accelerates, ocean waters are becoming less hospitable for a variety of marine life. The ocean is getting warmer and more acidic as it absorbs growing amounts of atmospheric carbon dioxide.

Measuring changes in the ocean is essential to understanding how human activities are impacting all life on Earth. But because the ocean is so vast and deep, some parts are hard to study without prohibitively expensive equipment. The cyborg jellies could offer a way for humans to wade into these relatively uncharted waters.

Moon jellyfish are the most energy-efficient animals on the planet. They’re prehistoric, with a simple body structure that has stayed the same for more than 500 million years. As invertebrates, they also lack a brain or spinal cord, though they do have basic organs and a pair of overlapping nerve nets. Importantly, the jellies do not have nociceptors, or sensory receptors that can detect potentially harmful stimuli.

Moon jellies can range from a centimeter to more than a foot in diameter. Their short, fine tentacles help them sting and catch prey like zooplankton, crustacean larvae and small fish. But thankfully for Xu, their sting cells can’t penetrate human skin.

Though they’re often found near coastlines, close to their favorite food sources, moon jellies live in diverse habitats worldwide and can swim to incredible depths: They’ve been found in some of the lowest places on Earth, including the Mariana Trench, which sits roughly 36,000 feet beneath the western Pacific Ocean’s surface at its deepest point.

Xu co-created the biohybrid robotic jellyfish concept with her former academic advisor about five years ago, and she first tested them in the field in 2020, steering them around shallow ocean waters off the coast of Woods Hole, Mass.

On top of the implications for ocean and climate research, Xu believes we can draw inspiration from the jellyfish.

“There’s really something special about the way moon jellies swim. We want to unlock that to create more energy-efficient, next-generation underwater vehicles,” she said.

Striving for ethical research

From left: Nicole Xu and graduate students Marshall Graybill and Charlie Fraga stand next to the main jellyfish tank in Xu's lab. (Credit: Glenn Asakawa)

Today, Xu spends much of her time studying precisely how moon jellies move through the water with such ease.

Xu, research associate Yunxing Su and graduate student Mija Jovchevska published a new study late last month that involved adding biodegradable particles to a jellyfish tank. The researchers then shone a laser through the tank to illuminate the suspended particles in the water and visualize how water flows when jellies swim.

In the past, researchers have used synthetic tracers such as silver-coated glass beads to look at underwater flow patterns, but the new study suggests biodegradable particles, such as corn starch, could be more sustainable, more affordable and less toxic alternatives.

She and graduate student Charlie Fraga are also working on making the jellyfish easier to steer in the wild. Going forward, Xu hopes to design other nature-inspired tools for studying the ocean.

There’s more to learn about the ethics of studying invertebrates. In a paper published earlier this year, Xu and others pointed out the need for more investigation of how research affects invertebrates. It was once widely believed that invertebrates couldn’t feel pain, but there is growing evidence that some do react to aversive stimuli.

Through all of her research, Xu says she strives to minimize harm to the animals she works with. When they’re stressed, moon jellies may secrete extra mucus, and they often stop reproducing. But Xu’s jellies have not shown increased mucus production, and small polyps—baby jellyfish the size of a pinhead whose tentacles are just beginning to form—line the inside of Xu’s jellyfish tanks.

“It's our responsibility as researchers to think about these ethical considerations up front,” Xu said. “But as far as we can tell, the jellyfish are doing well. They're thriving.”

Nicole Xu reaches her hand into the tank and touches one of the moon jellyfish. (Credit: Glenn Asakawa)

From left: Nicole Xu and graduate students Marshall Graybill and Charlie Fraga stand next to the main jellyfish tank in Xu's lab. (Credit: Glenn Asakawa)

Credit

Glenn Asakawa/University of Colorado Boulder

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Journal

Physical Review Fluids

DOI

10.1103/bg66-976x 

Article Title

Biodegradable tracer particles for underwater particle image velocimetry

 

UCF researcher helps confirm genetic restoration success for Florida panthers

A new study, co-authored by UCF Assistant Professor of Biology Robert Fitak, reveals that the 1990s translocation of Texas pumas improved the Florida panther’s genetic health while preserving its unique ancestry, offering insights for future conservation

University of Central Florida

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Once on the brink of extinction, a 1990s genetic restoration effort helped the Florida panther rebound and improve its genetic health.

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Credit: Photo credit: Ana Hidalgo

In 1995, scientists translocated eight Texas pumas into Florida in a genetic restoration effort to save the only viable puma population east of the Mississippi from extinction, the Florida panther.

The move raised concerns about harmful mutations and genetic swamping — or loss of unique traits. However, a recent study co-authored by UCF Assistant Professor of Biology and Genomics and Bioinformatics faculty cluster member Robert Fitak, found that since the introduction, genetic variation has significantly improved; unique traits have been retained; and harmful mutations, while still present, are largely masked by the restored genetic variation.

Findings from the study, published in the Proceedings of the National Academy of Sciences and led by UCLA researcher Diana Aguilar-Gómez with colleagues, suggest that this rescue model could guide future conservation efforts for other endangered species facing similar threats.

In the 1990s, fewer than 30 Florida panthers remained in the wild. Habitat loss, isolation and unregulated hunting drove the species to their record-low numbers. The steep decline led to inbreeding, causing developmental, reproductive and immunological impairments that spelled a devastating future for the species.

“If the panthers had continued inbreeding, the population would have been driven to extinction,” Fitak says. “The only way to recover them was to restore the genetic variation they had lost. ”

While the introduction helped the population rebound to between 120 to 230 individuals, according to the Florida Fish and Wildlife Conservation Commission, researchers wanted to know if the species’ genetic health improved and if their genetic ancestry was being replaced.

“My colleagues sequenced the entire genome of 29 post-rescue Florida panthers and combined it with genomes generated from my group and others to create a larger genomic analysis,” Fitak says.

The study found mixed Florida-Texas ancestry, with 24% to 61% Texas ancestry, indicating increased genetic variation measured by heterozygosity — a marker of how much genetic variation individuals carry.

It also found no evidence of genetic swamping — when genes from one population, such as Texas pumas, overwhelm and dilute the genetic makeup of another, such as Florida panthers. The panthers with mixed ancestry retained on average 59% to 80% Florida ancestry. Over time, Florida ancestry even increased, alleviating fears that the Texas genes would dominate the population’s unique traits.

“One of the risks of introducing Texas pumas was the loss of traits that make Florida panthers unique, but that was not the case,” Fitak says. “Their DNA was still intact and had spread to the individuals we studied. Post-rescue generations were genetically, physiologically and morphologically the same as pre-rescue Florida panthers.”

Moreover, post-rescue panthers carried fewer harmful mutations or deleterious variants, which were not removed but largely masked by the additional genetic variation from Texas pumas.

“Another fear was the possibility of introducing more harmful mutations that would worsen an already vulnerable population, but the opposite happened,” Fitak says. “Bringing in Texas pumas helped offset negative mutations and improved the population’s overall health.”

While the findings have been largely positive, researchers remain cautiously optimistic about the long-term results.

“It’s clear that without the genetic rescue 30 years ago, we probably wouldn’t have a Florida panther today,” Fitak says. “That’s why ongoing monitoring is critical. If their numbers drop and inbreeding rises again, we need to act quickly before facing the same problem.”

He adds that the study underscores the importance of building on research data collected over time.

“The project was a major collaboration led by several scientists and relied heavily on data gathered by multiple groups in previous studies,” Fitak says. “Making such data publicly available is crucial for advancing future research.”

On the broader significance, he says that understanding what worked for Florida panthers could help improve outcomes for other species facing similar declines.

“This kind of intervention will likely become more common as more iconic megafauna in the country and around the world decline,” Fitak says. “Studying its effects in Florida panthers helps us refine the approach and make it more effective for future conservation efforts.”

Aside from the genetic challenges, the Florida panther is also facing another major threat: habitat loss and degradation.

“Continued development in Florida is eating away at the spaces panthers need for survival.” Fitak says. “Development also indirectly impacts water quality and displaces the prey they rely on for food.”

While genetic restoration may have given Florida panthers a second chance, Fitak stresses that monitoring and habitat protection remain critical for their survival. Beyond safeguarding a single species, the effort has ripple effects across an entire ecosystem and holds significance for Floridians who view the panther as the state’s icon.

“Florida panthers are a symbol of the state’s wild heritage,” Fitak says. “Protecting this top predator isn’t just about saving one animal — it’s about preserving the health of an entire ecosystem for future generations.”

Florida panther samples were collected using funding from the Florida Panther Research and Management Trust Fund.

Researcher Credentials:
Fitak is an assistant professor in UCF’s Department of Biology in the College of Sciences. He received his doctorate in genetics from the University of Arizona and his bachelor’s in molecular genetics from The Ohio State University. Before joining UCF in 2019, he worked as a postdoctoral researcher at the Institute for Population Genetics in Vienna, Austria, and at Duke University. He is a member of UCF’s Genomics and Bioinformatics research cluster.

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2410945122 

Article Title

Proceedings of the National Academy of Sciences

 

Individuals should be held to account for environmental damage, say experts

And the UK should take the lead by adopting its own legislation

BMJ Group

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Individuals should be held accountable for “ecocide,” the most serious acts of environmental destruction, argue experts in The BMJ today.

And they say the UK should take on a leadership role by adopting legislation of its own to criminalise ecocide and inspiring other nations to protect our planet.

The term “ecocide” was coined in 1970 by biologist Arthur Galston, who condemned the large scale environmental devastation caused during the Vietnam War, they explain.

Fifty years on, as the world grapples with the escalating consequences of climate change, including sea level rises and biodiversity loss, momentum is building to establish ecocide as a new international crime so that individuals can be held accountable for the most serious acts of environmental destruction.

In May 2025, Scotland introduced a bill to criminalise ecocide, joining other countries including Argentina, Belgium, Dominican Republic, Italy, the Netherlands, and Peru.

A proposal to add ecocide to crimes within the jurisdiction of the International Criminal Court (ICC) would also be an important step towards accountability for serious environmental damage.

However, the authors note that under the ICC framework, states remain primarily responsible for investigating and prosecuting core crimes, reinforcing the need for domestic efforts to support international criminalisation of ecocide.

The UK therefore has an opportunity to take on a leadership role by adopting its own legislation, they write, noting that a bill to criminalise ecocide was introduced in 2023 but has not moved forward. 

Criminalising ecocide would bring various benefits, they say. For example, the spectre of personal accountability of decision makers—whether public officials or corporate executives—may provide a powerful deterrent than attributing responsibility to organisations alone.

Moreover, criminal law carries expressive power. “Treating environmental harm not merely as a regulatory issue but also as a criminal act conveys a strong message about societal values and priorities. This can change consciousness and drive meaningful changes in human behaviour and policies,” they add.

And they point out that a domestic prohibition on ecocide in the UK has wide support. In an Ipsos survey conducted in 2024 among 22,000 participants from G20 countries, 72% of respondents supported the criminalisation of ecocide. In the UK, this figure was 78%.

“Embracing the campaign for the criminalisation of ecocide is an opportunity for the UK to act on this consensus and position itself as a global leader, inspiring other nations to protect our planet and ultimately ensuring a sustainable future for generations to come,” they conclude.

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Journal

The BMJ

DOI

10.1136/bmj.r1715 

Method of Research

Commentary/editorial

Subject of Research

Not applicable

Article Title

Editorial: Criminalising ecocide

Article Publication Date

20-Aug-2025

COI Statement

Competing interests: The BMJ has judged that there are no disqualifying financial ties to commercial companies. The authors declare no other interests.

 

Companies may be misleading parents with “outrageous claims” about banking baby teeth

Experts alarmed by “outrageous” treatment claims for autism and diabetes; Several claims to be reviewed by Advertising Standards Agency

BMJ Group

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Parents are spending thousands of pounds to bank stem cells from their children’s milk teeth – but the recipient companies’ claims about their future medical value are unproven and potentially misleading, reveals an investigation by The BMJ, published today.

The companies’ claims include that stem cells banked from teeth are already being used in treatments for autism and diabetes. They also highlight current research using stem cells in multiple sclerosis, Parkinson’s disease, and heart attacks.

Tooth stem cell banking involves parents sending their children’s lost milk teeth to a laboratory where the dental pulp stem cells are harvested and stored. The service costs around £1900 (€2189; $2573) with an additional annual storage fee of £95, explains freelance journalist Emma Wilkinson. 

The three companies in the UK offering tooth stem cell banking – Future Health Biobank, BioEden and Stem Protect – all operate through one laboratory. 

Future Health Biobank says on its website that it has released 26 tooth stem cell samples for treatment, including for autism, type 1 diabetes, and knee cartilage regeneration, all to private clinics in North America.

BioEden states it has "already witnessed the remarkable evidence of these ongoing developments” among its own customers, while Stem Protect cites cleft palate repair, sickle cell disease, HIV/AIDS, severe combined immunodeficiency, and knee cartilage repair under a section of its website headed, ‘What treatments are tooth stem cells used for?’

But several experts are concerned about the claims being made, which they say risk exploiting parents, with the autism treatment promise deemed particularly “outrageous.”

Jill Shepherd, senior lecturer in stem cell biology at the University of Kent, says companies are selling the “potential” for something that is not yet borne out by the science. “There is a lack of evidence and a paucity of research using dental pulp stem cells to treat patients.”

Sufyan Hussain, an investigator on the UK arm of a global clinical trial evaluating stem cell therapy for type 1 diabetes, also has concerns about what is being promised. “At present, there isn't a definitive answer regarding the optimal source of stem cells for future diabetes therapies,” he says.

Tim Nicholls, assistant director of policy, research and strategy at the National Autistic Society in the UK, adds: “It’s outrageous that tooth stem cell procedures are being advertised to parents with the false claim of ‘treating’ autism.

“Autism is not a disease or illness, it cannot be treated and there is no cure. It is dangerous and morally bankrupt to target potentially vulnerable people with expensive procedures that could, in fact, cause harm.”

Experts are also concerned about the lack of independent information on tooth stem cell banking to help consumers make a fully informed choice, and say more oversight is needed of the information being used to promote the practice. 

Jill Shepherd also believes parents should be given more information on what type of tests are done to validate that stem cells are present in the stored samples, that the samples have been collected properly, and the evidence on how long such samples can be viably stored.

The BMJ has raised several concerns about how the service is promoted on all three company websites with the Advertising Standards Agency, which it says it will review.

In response, Future Health Biobank says it is reviewing how information on its site is presented to ensure “readers can clearly distinguish between client experiences and formally published clinical outcomes.” 

The company also says it has a “robust, ongoing, storage stability validation programme” with quality control testing “to ensure that there is no deterioration in the integrity, viability or future potential of biological samples.”

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Journal

The BMJ

DOI

10.1136/bmj.r1491 

Article Title

Investigation: Banking baby teeth: companies may be misleading parents with “outrageous claims”

Article Publication Date

20-Aug-2025