Latest news with #YoungerDryas
Gizmodo
11 hours ago
- Science
- Gizmodo
New Study Fuels Debate Over World-Changing Comet Strike 12,800 Years Ago
Roughly 12,800 years ago, as Earth was emerging from its last great ice age, temperatures in the Northern Hemisphere suddenly plummeted back to near-glacial conditions. The cause of this abrupt shift—known as the Younger Dryas cool period—remains a mystery to this day, but new evidence may give credence to its most controversial explanation. Researchers analyzed sediment cores extracted from the seafloor of Baffin Bay near Greenland, finding indicators of a cosmic impact event inside the layer that correlates to the Younger Dryas. The findings, published August 6 in the journal PLOS One, suggest that a comet—or its remnants—exploded in Earth's atmosphere at around the same time that this 1,200-year-long cold snap began. The study offers new support for the Younger Dryas Impact Hypothesis. In 2007, researchers proposed that fragments of a disintegrating comet or asteroid struck Earth around 12,800 years ago, triggering wildfires across North America. Such a calamity would have produced enough soot and ash to blot out the Sun and plunge the Northern Hemisphere back into a colder state. It's an elegant explanation, but a highly contested one. Researchers haven't found an impact crater that would prove this event took place, so proponents largely rely on geochemical evidence found in sediment layers that date back to just before the Younger Dryas began. Amid a lack of definitive evidence for the Younger Dryas Impact Hypothesis, most experts instead subscribe to the Meltwater Pulse Hypothesis, which suggests that a deluge of freshwater from the melting ice sheet that covered most of North America during the Pleistocene temporarily interfered with Earth's heat-transporting ocean currents. Previous geochemical evidence from ocean sediment cores supports this idea, but scientists have yet to determine the exact route taken by this apparent flood. The authors of this latest study, led by University of South Carolina archaeologist Christopher R. Moore, suggest that both hypotheses may be true. 'The [Younger Dryas Impact Hypothesis] is often cited as an alternative to the Meltwater Pulse Hypothesis,' Moore said in an interview with PLOS One. 'What many don't understand is that the YDIH proposes the impact event (potentially involving many thousands of impacts and airbursts globally) would destabilize the glacial ice sheet in the Northern Hemisphere, leading to the collapse of massive glacial meltwater lakes and subsequently shutting down the ocean's conveyor belt.' Previous studies of terrestrial sediment cores have found geochemical clues of a comet impact around the onset of the Younger Dryas, but Moore and his colleagues wanted to see whether ocean cores would contain the same clues. If so, this would dispel arguments that land-based evidence of a Younger Dryas impact event resulted from ancient human activities, according to Moore. His team uncovered multiple impact proxies that date back to the appropriate time period inside the ocean cores, including metal particles with compositions that suggest cometary origin and iron- and silica-rich microspherules. Still, not everyone is convinced. 'I do not see anything in this new paper that overcomes the chronic and ongoing problems with their previous papers,' Mark Boslough, an applied physicist and research professor at the University of New Mexico, told Gizmodo in an email. As an outspoken critic of the Younger Dryas Impact Hypothesis, he believes there are much simpler explanations that are more consistent with our current understanding of impact and airburst physics, earth science, and astronomy. 'On the surface, they report materials that sound exotic and impressive, but these are not expected results of extraterrestrial events, and I don't think the authors seriously considered more ordinary explanations,' Boslough said.
Yahoo
10-08-2025
- Science
- Yahoo
Evidence of World-Changing Comet Explosion 12,800 Years Ago Found in The Ocean
Microscopic grains of alien dust buried in the sediment at the bottom of the ocean could be evidence of a comet that exploded in Earth's atmosphere 12,800 years ago. This hypothetical event, known as the Younger Dryas impact, was invoked to explain a sudden, 1,200-year period of rapid cooling to near-glacial conditions during a time when Earth's climate was on a warm upswing. It's a controversial proposal, to say the least, with many scientists roundly rejecting it while others remain more open to the possibility. One of the leading refutations is that no crater has been found, as one might expect from such a world-changing event… but the evidence may be much smaller than a crater. Related: Led by geoscientist Christopher Moore of the University of South Carolina, a team of researchers puts forward a new line of evidence: four sediment cores from Baffin Bay near Greenland. These are cylinders of material excavated vertically that preserve layers upon layers of seafloor sediment that were deposited over many millennia. "We chose to analyze marine cores from Baffin Bay to determine if Younger Dryas impact proxies reported from dozens of terrestrial sites globally were present in ocean cores," Moore explains in an interview with the science journal PLOS One. "The sites were significant because they were a considerable distance from potential anthropogenic [human] contamination, and in most cases, the cores were highly laminated, indicating that the record was relatively undisturbed." The researchers used radiocarbon dating to determine the ages of the layers, and then used a technique called single-particle inductively coupled plasma time-of-flight mass spectrometry to look for signs of comet dust in the layers deposited during the time of the Younger Dryas cooling. This analysis revealed tiny particles of metal with compositions consistent with a cometary origin, including iron with low oxygen and high nickel content, and microspherules rich with iron and silica. These microspherules, the researchers say, consist mostly of material from Earth, but with a little bit of impactor material mixed in – likely from an airburst event as the comet exploded after atmospheric entry. "The Younger Dryas sediment layer in the Baffin cores contains multiple proxies consistent with an impact event. Microspherules, twisted and deformed metallic dust particles with chemistry consistent with comet or meteoritic material, meltglass, and identification of nanoparticle peaks in key elements (e.g., platinum and iridium) suggest an impact event," Moore says. "This evidence is supported by the findings on terrestrial sites on multiple continents in both hemispheres. This work builds on other evidence that the Younger Dryas impact event was likely global in scale." The researchers next plan to broaden the scale of their investigation by examining sediment cores from other ocean sites around the world. Their findings have been published in PLOS One. Related News 'Hot Blob' Heading For New York Following Ancient Greenland Rift Prehistoric Air Has Been Reconstructed From Dinosaur Teeth in an Amazing First Lightning Kills Way More Trees Than You Would Ever Believe Solve the daily Crossword
Daily Mail
08-08-2025
- Science
- Daily Mail
Groundbreaking find uncovers catastrophic event linked to destruction of legendary Atlantis
A discovery beneath the ocean floor has revealed evidence of a catastrophic event that may be linked to the destruction of the legendary lost city of Atlantis. Some researchers, including well-known author Graham Hancock, have long proposed that around 12,800 years ago, a giant comet passed through Earth's atmosphere, triggering devastation that wiped out advanced civilizations worldwide. While credible proof of Atlantis itself remains elusive, scientists have now uncovered geochemical clues supporting the theory of this cataclysmic event, known as the Younger Dryas. The controversial Younger Dryas Impact Hypothesis (YDIH) suggests Earth passed through debris from a disintegrating comet. The resulting impacts and shockwaves destabilized massive ice sheets, causing massive flooding that disrupted crucial ocean currents and triggered rapid climate cooling. Now, researchers led by the University of South Carolina have uncovered metallic debris, like comet dust and thousands of tiny microspherules, in Baffin Bay seafloor sediments, strengthening the comet impact theory. Archaeologist Marc Young, co-author of the study, told the Daily Mail: 'The Younger Dryas onset is associated with significant changes in human population dynamics all over the planet, though mostly in the northern hemisphere. 'Several independent studies over the last few years have shown conclusively that most of the megafaunal species that went extinct disappeared precisely at that time.' Many mainstream scientists argue that the cooling was caused not by a comet but by glacial meltwater flooding the Atlantic Ocean. This influx of fresh water weakened ocean currents that transport warm tropical waters northward, leading to the temperature drop. However, Young pointed out that 'such cooling events have occurred dozens of times over the last 100,000 years, but none caused megafauna extinctions, wiped out human populations, or deposited a global layer of impact debris like the YD did.' He added: 'Furthermore, the release of meltwater into the oceans at the YD onset was orders of magnitude larger than previous events, causing a near-instantaneous global sea level rise of over 16 feet, while past sea level rises during similar coolings were negligible.' The sediment cores analyzed by the team serve as historical records, preserving layers of mud, sand and particles deposited over millennia. By examining these layers, scientists can reconstruct past climates, ecosystems and geological events. The four cores were collected from locations spanning about 620 miles across Baffin Bay, from shallow waters near Jones Sound to deeper areas near Davis Strait. The cores were taken from water depths between 1,640 and 7,870 feet. Iron-rich and silica-rich tiny spherical particles, or microspherules, were found in layers of the sediment cores dating back 12,800 years. These microspherules formed at very high temperatures, with bubbles, branching surface patterns and aerodynamic shapes that suggested they traveled fast through the air. The iron-rich microspherules also contained small blobs of a low-oxygen metal that is chemically between chromite and chromium-magnetite, minerals found in certain types of meteorites and impact materials. Led by Christopher R Moore, the researchers also detected a pronounced spike in platinum, a rare element often enriched during extraterrestrial impacts, in the same sediment layers containing the microspherules and comet dust. Fragments of melted glass and grains were also found, including melted clusters with iron-rich particles and quartz that melted or boiled at very high temperatures. These also included glass rich in iron, chromium, potassium and titanium. Small blobs of melted chromite, iron-chromium-nickel alloys, iron oxide, and tungsten were found fused onto quartz and magnetite grains from the Younger Dryas Boundary layers in the cores. These metallic blobs mostly consist of native nickel, iron-chromium-nickel alloys, and chromite, and they look very similar to melted splatters on minerals found in South Carolina that have been identified as cometary dust particles. Young emphasized the significance of this ocean-based evidence: 'Until now, no oceanic sediment cores had been used to test the Younger Dryas Impact Hypothesis. 'This is the first and only ocean-based geochemical evidence for the hypothesis since it was proposed in 2007. 'Importantly, it's the first time anyone has looked, and finding this evidence on the very first attempt is very promising. Technically, we have a 100 percent replication rate in ocean cores based on this data.' These findings indicate a geochemical anomaly occurring around when the Younger Dryas event began, but they do not provide direct evidence supporting the impact hypothesis, according to the team. More research is needed to confirm whether the findings are indeed evidence of impact, and to firmly link an impact to climate cooling. 'Our identification of a Younger Dryas impact layer in deep marine sediments underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts,' Moore said. Co-author Dr Mohammed Baalousha added: 'It is great to implement our unique nano-analytical tools in a new area of study, namely the analysis of nanoparticles generated or transported to the Baffin Bay core site during the Younger Dryas.
Yahoo
18-06-2025
- Science
- Yahoo
Supernova may have caused an ice age: Study
(NewsNation) — A supernova could have triggered one of the Earth's ice ages, something that could happen again in the future. A new study revealed the timing of the Vela supernova aligned with a period known as the Younger Dryas, when global temperatures dropped and ice sheets began advancing. Scientists believe the exploding star bombarded the planet with radiation that severely damaged the ozone layer based on tree ring records showing a spike in radioactive carbon-14, which indicates atmospheric radiation increased. Bobcat Fever: Deadly disease that kills cats in the Midwest Ice cores also revealed a decrease in methane concentrations, and archaeological sites across North America have 'black mat' deposit,s and fossil records show the extinction of mammals, including the mammoth and saber-toothed cats. Without protection from the ozone layer, harmful ultraviolet radiation would reach the surface of the Earth, triggering massive wildfires and causing DNA damage to plants and animals. The study also found several other potential connections between supernova incidents and changes in the Earth's climate. Toxic-exposed veterans: Bill calls for more research on health issues among families Other scientists are skeptical about the results, pointing out alternative explanations, including ocean circulation disruptions from freshwater floods, solar storms spiking carbon-14 and mammal extinctions due to asteroid impacts or human hunting. If supernovas are the cause, it could be something the Earth faces again. Several nearby stars could become future supernovas, including a red giant called Betelgeuse that may explode within the next million years. A supernova might not necessarily cause a mass extinction, but it could still have impacts on the planet's atmosphere and climate. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
01-05-2025
- Science
- Yahoo
Archaeologists Found 11,500-Year-Old Tools That Reveal an Incredible Human Adventure
Researchers discovered tools dating as far back as 11,500 years. The tools could be evidence of the earliest human settlement in Scotland. Nomads likely crossed into the Isle of Skye via Doggerland—an area that is now covered by the North Sea. Humans love convenience, and that's a love as old as time (well, maybe that's a stretch). The oldest tools discovered thus far date back to our early ancestors, around 2.6 million years ago. While these tools were rudimentary (often unaltered sticks and rocks found on the ground), they played a key part in the broader story of human evolution. Not only were they helpful to the early humans who used them back then, but early tools like these also serve as valuable clues for scientists today. Case in point, a research team just found tools on the Isle of Skye which shed light on Scotland's oldest inhabitants. Researchers dated these new-found Scottish tools back to between 11,500 and 11,000 years ago, during what is called the Late Upper Paleolithic. The 'Upper' part of the Paleolithic Period is a subdivision marked by the development of more advanced tools. The discoveries mean the west coast of Scotland now represents the largest concentration of evidence proving the early presence of people in the area, according to a press release. The team consisted of researchers from universities of Leeds, Sheffield, Leeds Beckett, and Flinders in Australia. Together, they worked to reconstruct the landscape and changing sea levels of the time. They determined that nomads likely crossed into Skye when much of western Scotland was buried under ice after the Younger Dryas—a sudden cooling period that froze much of the Northern Hemisphere. Researchers theorize that the pioneers crossed via Doggerland, which is now covered by the North Sea. According to Karen Hardy, leader of the team, the nomads' journey to the Isle of Skye was the 'ultimate adventure story.' She explained in the release that as they followed animal herds northward and entered Scotland, the landscape changed to one that was icy and treacherous. 'A good example of the volatility they would have encountered can be found in Glen Roy,' Hardy said in the press release, 'where the world-famous Parallel Roads provide physical testament to the huge landscape changes and cataclysmic floods that they would have encountered, as they travelled across Scotland.' Once in Scotland, the pioneers had to adapt to live among the melting glaciers, oceans, and mountains—conditions that were shockingly different from their former homelands in the northwestern Great European Plains. Hardy believes the settlers strategically chose where to base themselves to best access coastal and riverine resources. They also began to value ochre—a pigment that was important to ancient cultures. Although the exact terrains the nomads crossed can no longer be visited, they can be imagined at places like Sconcer, a township on the same island where the tools were discovered. Needless to say, these findings were crucial in advancing knowledge of ancient Scotland. 'This is a hugely significant discovery which offers a new perspective on the earliest human occupation yet known, of north-west Scotland,' Hardy said. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
