Decoding mysterious seismic signals

Utah geophysicists find link between seismic waves called PKP precursors and anomalies in Earth's mantle

University of Utah

 

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Graphic illustration of Earth's interior.

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Credit: Michael Thorne, University of Utah

For the decades since their discovery, seismic signals known as PKP precursors have challenged scientists. Regions of Earth’s lower mantle scatter incoming seismic waves, which return to the surface as PKP waves at differing speeds.

The origin the precursor signals, which arrive ahead of the main seismic waves that travel through Earth’s core, has remained unclear, but research led by University of Utah geophysicists sheds new light on this mysterious seismic energy.

PKP precursors appear to propagate from places deep below North America and the western Pacific and possibly bear an association with “ultra-low velocity zones,” thin layers in the mantle where seismic waves significantly slow down, according to research published in AGU Advances, the American Geophysical Union’s lead journal. (The AGU highlighted the research in its magazine Eos.)

“These are some of the most extreme features discovered on the planet. We legitimately do not know what they are,” said lead author Michael Thorne, a U associate professor of geology and geophysics. “But one thing we know is they seem to end up accumulating underneath hotspot volcanoes. They seem like they may be the root of whole mantle plumes giving rise to hotspot volcanoes.”

These plumes are responsible for the volcanism observed at Yellowstone, the Hawaiian Islands, Samoa, Iceland and the Galapagos Islands.

“These really, really big volcanoes seem to persist for hundreds of millions of years in roughly the same spot,” Thorne said. In previous work, he also found one of the world’s largest known ultra-low velocity zones.

“It sits right beneath Samoa, and Samoa is one of the biggest hotspot volcanoes,” Thorne noted.

For nearly a century, geoscientists have used seismic waves to probe Earth’s interior, leading to numerous discoveries that would not be otherwise possible. Other researchers at the U, for example, have characterized the structure of Earth’s solid inner core and tracked its movement by analyzing seismic waves.

When an earthquake rattles Earth’s surface, seismic waves shoot through the mantle—the 2,900-kilometer-thick dynamic layer of hot rock between Earth’s crust and metal core. Thorne’s team is interested in those that get “scattered” when they pass through irregular features that pose changes in material composition in the mantle. Some of those scattered waves become PKP precursors.

Thorne sought to determine exactly where this scattering happens, especially since the waves travel through Earth’s mantle twice, that is, before and after passing through Earth’s liquid outer core. Because of that double journey through the mantle, it has been nearly impossible to distinguish whether the precursors originated on the source-side or receiver-side of the ray path.

Thorne’s team, which included research assistant professor Surya Pachhai, devised a way to model waveforms to detect crucial effects that previously went unnoticed.

Using a cutting-edge seismic array method and new theoretical observations from earthquake simulations, the researchers developed, they analyzed data from 58 earthquakes that occurred around New Guinea and were recorded in North America after passing through the planet.

“I can put virtual receivers anywhere on the surface of the earth, and this tells me what the seismogram should look like from an earthquake at that location. And we can compare that to the real recordings that we have,” Thorne said. “We’re able to now back project where this energy’s coming from.”

Their new method allowed them to pinpoint where the scattering occurred along the boundary between the liquid metal outer core and the mantle, known as the core-mantle boundary, located 2,900 kilometers below Earth’s surface.

Their findings indicate that the PKP precursors likely come from regions that are home to ultra-low velocity zones. Thorne suspects these layers, which are only 20 to 40 kilometers thick, are formed where subducted tectonic plates impinge on the core-mantle boundary in oceanic crust.

“What we’ve now found is that these ultra-low velocity zones do not just exist beneath the hotspots. They’re spread out all across the core-mantle boundary beneath North America,” Thorne said. “It really looks like these ULVZs are getting actively generated. We don’t know how. But because we’re seeing them near subduction, we think mid-ocean ridge basalts are getting melted, and that is how it’s getting generated. And then the dynamics is pushing these things all across Earth, and ultimately they’re going to accumulate beneath the hotspots.”

“What we’ve now found is that these ultra-low velocity zones do not just exist beneath the hotspots. They’re spread out all across the core-mantle boundary beneath North America,” Thorne said. “It really looks like these ULVZs are getting actively generated. We don’t know how. But because we’re seeing them near subduction, we think mid-ocean ridge basalts are getting melted, and that may be how they’re getting generated.”

The dynamics is pushing these things all across Earth, and ultimately, they’re going to accumulate against the boundaries of Large Low Velocity Provinces, which are compositionally distinct continent scale features beneath the Pacific and Africa, according to Thorne.

“They may additionally accumulate beneath the hotspots, but it is unclear if these ULVZs are generated by the same process,” he said. Determining the consequences of such a process will have to wait for future research.

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The study, “Investigating Ultra-Low Velocity Zones as sources of PKP scattering beneath North America and the Western Pacific Ocean: Potential links to subducted oceanic crust,” was published in the August edition of AGU Advances. Co-authors include Surya Pachhai, now a research assistant professor in the U’s Department of Geology & Geophysics. This research, funded by the National Science Foundation, was conducted in collaboration with geoscientists at Arizona State University and University of Leeds in the U.K.

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Journal

AGU Advances

DOI

10.1029/2024AV001265 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Investigating Ultra-Low Velocity Zones as sources of PKP scattering beneath North America and the Western Pacific Ocean: Potential links to subducted oceanic crust

Article Publication Date

10-Aug-2024

 

Ancient DNA reveals Indigenous dog lineages found at Jamestown, Virginia

Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

 

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An aerial view of James Island and James Fort. The Jamestown colony was established in Tsenacomoco, the Algonquian name for the Powhatan chiefdom in the tidewater areas of the Chesapeake Bay and later became the Commonwealth of Virginia.

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Credit: Jamestown Rediscovery

Previous scientific studies have indicated that North American dog lineages were replaced with European ones between 1492 and the present day. To better understand the timing of this replacement, researchers from the University of Illinois Urbana-Champaign and the University of Iowa sequenced mitochondrial DNA from archaeological dogs. Their findings suggest a complex social history of dogs during the early colonial period. 

Europeans and Native Americans valued their dogs as companion animals, using them for similar work and as symbols of identity. Consequently, the dogs reflected the tension between European and Indigenous cultures—the settlers described Indigenous dogs as mongrels to emphasize the perception that Indigenous people did not breed or own their dogs. Indigenous peoples identified European dogs as a direct threat to their existence and took measures to limit the use of European dogs. 

“Previous studies had suggested that there were a lot of Indigenous dogs in the continental United States and that they were eradicated,” said Ariane Thomas, a recent PhD graduate of anthropology at the University of Iowa. “We wanted to understand what that entailed: when it happened, were they culled, was it the competition with European dogs, or was it disease?”

The researchers focused on the Jamestown colony in Virginia due to the number of canid remains available at the site and the evidence of Indigenous influence. They worked with Jamestown Rediscovery to identify and analyze 181 canid bones that represented at least 16 individual dogs. Of these, the team selected 22 remains that spanned multiple time points of the early settlement at Jamestown, between 1607 and 1619. They extracted the DNA at the ancient DNA lab in the Core Facilities of the Carl R. Woese Institute for Genomic Biology. The researchers then sequenced the data at the Roy J. Carver Biotechnology Center at Illinois to better understand the ancestry of these dogs.

“This project is a great example of the type of team science that we use at IGB, where people from diverse fields come together to answer questions through the use of complementary skill sets,” said Alida de Flamingh, a postdoctoral researcher in the Malhi (CIS/GSP/IGOH/GNDP) lab. 

Based on body size estimates alone, the team discovered that most of the Jamestown dogs weighed between 22-39 lbs, comparable to modern-day beagles or schnauzers. Furthermore, many of the dog bones showed traces of human-inflicted damage, including burning and cut marks. 

“The cut marks and other butchery marks we found on them show that some of these dogs were eaten. It implies that when the colonists came over, they didn’t have enough food and they had to rely on the Indigenous dogs in the area,” Thomas said.

Additionally, the DNA sequences demonstrated that at least six of the dogs showed evidence of Indigenous North American ancestry. “Our results show that there were Indigenous dogs in the area and they weren’t immediately eradicated when the Europeans arrived,” Thomas said.

Although the identification of dogs with Indigenous ancestry is not surprising, the results suggest that the colonists and Indigenous tribes may have traded dogs and likely had little concern with possible interbreeding. The researchers are interested in expanding to other sites and obtaining more high-quality DNA samples and reconstructions of dog body size to shed light on whether these dogs had full Indigenous ancestry or whether they were the product of mating with European dogs.  

The study “The Dogs of Tsenacomoco: Ancient DNA Reveals the Presence of Local Dogs at Jamestown Colony in the Early Seventeenth Century” was published in American Antiquity and can be found at 10.1017/aaq.2024.25. The work was supported by the National Institutes of Health, the Wenner-Gren Foundation, the University of Illinois Urbana-Champaign, and the University of Iowa.

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Journal

American Antiquity

DOI

10.1017/aaq.2024.25 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

The Dogs of Tsenacomoco: Ancient DNA Reveals the Presence of Local Dogs at Jamestown Colony in the Early Seventeenth Century

 

As human activities expand in Antarctica, scientists identify crucial conservation sites

University of Colorado at Boulder

 

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An Adélie penguin swims in the Southern Ocean.

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Credit: John Weller

A team of scientists led by the University of Colorado Boulder has identified 30 new areas critical for conserving biodiversity in the Southern Ocean surrounding Antarctica. In a study published Aug. 15 in the journal Conservation Biology, the researchers warn that without greater protection to limit human activities in these areas, native wildlife could face significant population declines. 

“Many animals are only found in the Southern Ocean, and they all play an important role in its ecosystem,” said Cassandra Brooks, the paper’s senior author and associate professor in the Department of Environmental Studies and a fellow of the Institute of Arctic and Alpine Research at CU Boulder. “While Antarctica and the Southern Ocean feel really far away, they – and the life within them - are critical to the functioning of Earth systems,” 

The Southern Ocean is home to many beloved animals like Adélie penguins, Weddell seals and humpback whales. Its remote location and harsh conditions—including frigid temperatures and extensive sea ice—have largely protected biodiversity in Antarctica and the Southern Ocean from human activities. 

“Despite the planet being in the midst of a mass extinction, the Southern Ocean in Antarctica is one of the few places in the world that hasn’t had any known species go extinct,” said Sarah Becker, the paper’s first author and a doctoral student in the Department of Environmental Studies. 

But as climate change warms the planet and melts the sea ice, fishing and tourism in the region have increased. These human activities not only compete with wildlife for resources but could also cause stress, and introduce invasive species and diseases that native wildlife has little or no defense mechanisms against.  

Becker, Brooks and their team set off to identify Key Biodiversity Areas (KBAs) in the Southern Ocean that species depend on for their populations to persist.

They used existing tracking data for 13 Antarctic and sub-Antarctic seabirds and seals—for example Adélie penguins, sooty albatrosses and southern elephant seals— and identified 30 KBAs across the Southern Ocean. These sites represent marine habitats that species travel to for foraging, breeding and migration.

Prior work in identifying conservation zones in the Southern Ocean at a large scale tended to group different species into a single dataset to look for areas important for multiple species. While this approach is a vital component of conservation planning, it can overlook some areas crucial for certain species due to their unique life stages and migration patterns, Becker said. 

For example, the team found two large sites in the waters near Amanda Bay in East Antarctica that serve as key foraging grounds for many emperor penguins as they recover after breeding. The researchers also identified several sites in the waters near Campbell Island South of New Zealand where a breeding population of endangered grey-headed albatross forage. Other similar large-scale conservation designation efforts, such as Important Bird Areas or Ecologically and Biologically Significant Areas, had not flagged these sites as priorities.

“Our study bridges the gap between the broad-scale perspective and the specific needs of individual populations, adding an important layer of detail,” Becker said. 

The researchers hope international bodies and governments will consider these findings when developing conservation strategies and determining areas where fishing should be restricted. 

“By reducing fishing or tourism interactions in these key biodiversity areas, we can potentially give these animals the best chance of adapting and becoming resilient to climate change,” said Brooks, who is also a fellow of CU Boulder’s Institute of Arctic and Alpine Research.

The Southern Ocean is one of the most pivotal buffers of climate change. Its cold water captures 40% of human-generated carbon dioxide emissions around the world and 60-90% of the excess heat from climate change. 

“Antarctica is far away, but what happens there doesn’t stop there,” Brooks said. “Wildfires here in Colorado are tied to what's happening in the Southern Ocean. Through doing more to safeguard the Antarctic, we actually stand to create a more livable world for us all.”

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Journal

Conservation Biology

DOI

10.1111/cobi.14345 

Article Title

Scaling up ocean conservation through recognition of key biodiversity areas in the Southern Ocean from multispecies tracking data

Article Publication Date

15-Aug-2024

 

Exposing myths about ballot collection on Native American reservations

Utah researchers find ballot collection lowers barriers to voting for Native Americans, while resulting in no documented cases of vote fraud.

University of Utah

Third-party collection of mail-in ballots has helped rural residents and those with disabilities to vote, yet the practice has become contentious and the target of laws aimed at restricting it.

Critics claim the process is vulnerable to fraud and manipulation.

But new research from the University of Utah’s College of Social & Behavioral Science tells a different story. Ballot collection is more accurately characterized as a pathway for legitimate voter participation, according to a study published last month. Authors Daniel McCool, a professor emeritus in the Department of Political Science, and Weston McCool, a postdoctoral researcher in the Department of Anthropology, debunk misconceptions about ballot collection and document its benefits.

“There is considerable controversy regarding the role of third-party ballot collection in elections,” said Daniel McCool, who has testified as an expert witness in Native American voting rights lawsuits. “Our results indicate that ballot collection is a valued service on Indian reservations, and there is no evidence that it leads to voter fraud.”

The research appears in the July edition of the American Indian Culture and Research Journal.

Focusing on Indian reservations in Montana and other Western states, the father-son team assessed the costs and benefits of ballot collection through a blend of qualitative and quantitative analyses. Native American communities often rely on ballot collection due to various socioeconomic and logistical challenges associated with casting votes.

Sometimes negatively referred to as “ballot harvesting,” ballot collection is the practice of someone other than the voter turning in completed ballots to a post office or ballot box. It has become popular with the rise of mail-in voting, which makes it much easier to vote, but not necessarily for Native Americans who often lack home mail service. Supervised by tribal governments and nonprofits such as Western Native Voice, ballot collectors on reservations deliver tribal members’ ballots to a post office or polling station that can be miles from their homes.

“They collected hundreds of ballots from Native Americans who live in very, very remote places,” McCool said. “The reason why these native voters were taking advantage of the ballot collection service was because it’s very difficult for them to overcome those long distances and the poor transportation.”

Legislatures in Utah and three other Western states have tried to ban the practice in recent years in a move that tribes have denounced as a partisan effort to limit Native Americans’ ability to vote and has led to lawsuits

Many states have adopted restrictions on who can collect another person’s ballot or how many one person can collect. Some forbid ballot collectors from accepting payment, which effectively bans third-party collecting on reservations, according to McCool.

Nineteen states allowed only the voter, a family member or a caregiver to turn in a ballot during the study’s time frame. Of these, four have substantial Native American populations: Arizona, Oklahoma, New Mexico and Nevada.

Utah has since banned ballot collection by third parties under an election reform law unanimously passed in 2020.

By examining trends in vote-by-mail programs, socioeconomic variables, distance to polling stations and mail locations, and U.S. Postal Service delivery efficiency on reservations, the McCools documented how ballot collection improves the voting experience of Native Americans.

Their findings illustrate how ballot collection reduces inequality in the cost of voting for Native Americans. On reservations, where access to polling places and reliable mail services can be limited, ballot collection ensures these community members can exercise their right to vote without undue burden.

The statistical analysis conducted by the McCools found no evidence to support allegations that ballot collection leads to voter fraud, deflating the argument commonly used to restrict ballot collection practices.

“The evidence is actually collected by the conservative think tank, the Heritage Foundation,” McCool said. “We use their data to indicate that there’s no voter fraud associated with ballot collection.

The foundation’s database documents 1,850 cases of proven voter fraud, which resulted in convictions, going back to 1980 for all elections surveyed, from president to dogcatcher.

“Political scientists calculated the frequency of voter fraud based on the Heritage Foundation data,” McCool said. “The frequency is .00006%.”

Another way to frame that figure is to say there were six cases of proven fraud for every 10 million votes cast in the United States.

“The problem is not voter fraud,” McCool said. “The problem is the fraud about voter fraud.”

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Journal

American Indian Culture and Research Journal

DOI

10.17953/A3.19428 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Ballot Collection and Native American Voters: An Assessment of Benefits and Costs

JD Vance is a Redneck Uncle Tom

by Nicky Reid

 August 16, 2024
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Photograph Source: Ralph Branson – Public Domain

I come from a part of the country where people have become accustomed to getting played by elitist outsiders with name-brand suitcases packed full of empty promises. Somewhere between Pittsburgh and Philadelphia, where the Rust Belt fades into Amish Country, you’ll find my bitter heart surrounded by junked cars and haunted steeples. Gummo Country, I often half-jokingly refer to it as, after Harmony Korine’s modern Vuadville arthouse masterpiece. Not exactly the easiest place to grow up stuck between genders but I don’t think I could breathe anywhere else.

Say what you will about my neighbors, I often do, but much like me, they are people accustomed to getting fucked over and tired of putting up with the experience. These are the people who lost their jobs to NAFTA, lost their sons to bullshit wars in the Middle East, and lost pretty much everything else to Oxycontin. This is MAGA country, but these people didn’t vote for Donald Trump because they’re racist or sexist or xenophobic.

These people don’t vote for Republicans or Democrats. In fact, they don’t really vote for anyone at all. They vote against whichever Beltway rapist was the last one to fuck them up the ass without even spitting on their dick and Trump was just shrewd enough to get this. In 2016, that Wall Street con artist won over the Rust Belt by taking a ball bat to both of the partisan dynasties that fattened themselves more than most off of pillaging the holler, first the Bush Cartel in the primaries and then the Clintons under the big top.

Don’t get me wrong, many of my neighbors are hardcore bigots but they’re not fascists and they’re not imbeciles. They were well aware that Trump is a belligerent bologna salesman, but they cast their vote for that cunt like casting a brick through the White House window. You see, dearest motherfuckers, for Gummo Country, voting Trump was an act of revenge. But the results were more or less the same old song. The jobs didn’t come back from China, the Middle East kept on burning, and opioid addiction continued to provide the holler with its only growth industry aside from the local penitentiaries that it feeds.

But Donald Trump is a repeat offender who knows a good con when he sees one. Being seen seeing the forgotten Americans in these hills allowed him to hotwire the Electoral College once before and now he seems to think he can pull off this grift just one more time with a little help from “one of us” in his VP slot.

If you ask either side of the partisan divide who JD Vance is, political gripes aside, they are both likely to tell you the same story. The story of the son of Appalachian junkies who pulled himself up by the bootstraps and made something of his life, rising above the mud to become an inspiration to hillbillies and rednecks everywhere. A war hero and bestselling author turned working-class populist crusader, storming the Senate and putting America, our America, first. There is just one problem with this narrative but it’s a pretty big one. It’s about 90% bullshit.

JD Vance is actually a middle-class Midwestern suburbanite raised by Appalachian grandparents on the outskirts of Cincinnati. His parents were dicks, but his interactions with actual hillbillies growing up seem to be limited to random urchins he bumped into during part-time jobs on the bad side of town. Vance spent his time in the Marines avoiding any real combat as a glorified PR rep for the public affairs section of the Aircraft Wing where he likely picked up the bullshitting skills that he would polish as the editor of the prestigious Yale Law Journal.

Vance wrote his bestselling tearjerker, Hillbilly Elegy, on the suggestion of one of his professors, Amy Chua, who used her fame as the bestselling child abuse apologist behind Battle Hymn of the Tiger Mother to get her pupil the New York Times Review of Books treatment right out of the gates. By the time Hillbilly Elegy hit the shelves, Vance was already living the high life in San Francisco, working as a corporate lawyer for Big Tech goons like AOL’s Steve Case and PayPal’s Peter Thiel.

The latter oligarch would bankroll JD’s 2022 Senate campaign to the tune of $13 million dollars, and it was during this telltale campaign that Vance shed his previous visage as a neocon Never Trumper like a serpent and embraced his new drag as a MAGA GI Joe, promising to put America first and use the full weight of the Federal Government to annihilate the scourge of transgenderism. To put a long, gross story short; JD Vance is no Hillbilly hero. At best he’s a Redneck Uncle Tom, using his questionable heritage to fill his pockets with taxpayer dollars while he grows the government to lethal levels on culture war bullshit and shifts military industrial fun bucks from Ukraine to Israel.

Donald Trump picked JD Vance for his wingman for the same reason that Joe Biden picked another fraudulent representative of a fucked-over underclass for his VP. It’s a diversity hire that crassly tokenizes a marginalized section of the electoral map that another Northeastern country club racist needs to win. But much like Kamala the Cop, JD Vance’s most heinous crime isn’t simply pandering to poor people, it’s actively stoking the bigotry that keeps them desperate enough to vote for thuggish clowns like Trump.

Hillbilly Elegy, the book that made JD Vance a darling of the same liberal media that he now pretends to hate, is not a memoir about overcoming adversity. It is an openly elitist attack on the kind of people that I grew up with and Vance didn’t. Vance uses his deadbeat parents like hillbilly scarecrows and blames the woes of systemic disenfranchisement not on Wall Street poachers or Washington warmongers but on the very culture of the impoverished themselves, deriding rural rebellion against elitism as the “regressive” byproduct of a Celtic heritage that treats “poverty as the family tradition.”

JD’s suggested solution to our backward backwoods ways is to escape our “socially isolated” environment and join the more mainstream conservative class of Ivy League corporate creeps who rob us blind with big government handouts in the city.

After all, it worked for JD Vance. Hillbilly Elegy became a bestseller among upper-class liberal literati during the election season of 2016 for a reason. Every bougie, pearl-clutching, Beltway insider was looking for some way to explain how the Bush and Clinton’s lost control of their dupes in cousin-fucker country to a reality television shock jock and JD was their man, an Appalachian pedigreed deplorable-whisperer who could tell elitist fuckups from Bill Kristol to Wolf Blitzer that it wasn’t their fault that their abused pet electorate bit them. We were just born rabid.

And maybe he’s right. I may have spent my teens cursing redneck jocks for bashing me, but I stayed in this corner of the country for a reason. For all the bigotry that my neighbors all too often fall prey to, these people are still my people, and their culture makes sense to a genderfuck anarchist like me because it is one defined by resistance to mainstream American society. Whether you want to call them rednecks, hillbillies, or trailer trash, your average lower-class rural white person hates war, taxes, sobriety, cops, and wage slavery every bit as much as your average unassimilated Queer or an inner-city person of color. In fact, your average lower class rural white person isn’t really that white at all.

Most of our ancestors came to this country fleeing ethnic violence from the Celtic regions of the British Isles to work the farms and mines of Anglo-Saxon Protestants who considered us to be about as despicable as the Black folk toiling beside us. White wasn’t even a thing in this country until Celtic paupers and Black servants rose up together against our shared oppressors during Bacon’s Rebellion. Even then, most of us had to earn our white privilege the same way JD Vance earned his way into Washington, by assimilating to polite WASP culture and proving ourselves capable of slaughtering darker poor people.

I for one say enough with this melting pot bullshit. I am sick and tired of seeing my neighbors vilified as deplorables by racist frauds like Vance only to be manipulated into bashing their queerer cousins whenever the master class needs their votes. These elitist scum fucks don’t represent hillbilly culture any more than Kamala Harris represents Black culture or Pete Buttigieg represents Queer culture.

Hillbilly culture is a counterculture built in resistance to colonialist homogeny. These are the people who joined the slaves in seceding from the Confederacy to form West Virginia. These are the people who joined their fellow coal miners across the color lines to take on the National Guard during the Battle of Blair Mountain. These are the people who helped Fred Hampton’s Black Panthers build the original Rainbow Coalition as members of the Young Patriots Organization.

These are my neighbors and as a proud pink trash panarchist, I know firsthand that the only way to take on first world oppression is by joining third world resistance. Consider this hit piece against a shameless impostor to be an open invitation to a riot. You know where I live.

Nicky Reid is an agoraphobic anarcho-genderqueer gonzo blogger from Central Pennsylvania and assistant editor for Attack the System. You can find her online at Exile in Happy Valley.