Latest news with #EarthandPlanetaryScienceLetters
NDTV
5 days ago
- Science
- NDTV
Mystery Behind Antarctica Mountain Range Hidden For 500 Million Years Solved
Scientists have solved the mystery behind the mountain range buried under ice in East Antarctica for the last 500 million years. The mysterious and ancient Gamburtsev Subglacial Mountains are similar in shape and scale to the Alps, but not visible due to being trapped beneath kilometres of ice. First discovered by a Soviet expedition using seismic techniques in 1958, the Gamburtsev Mountains are buried beneath the highest point of the East Antarctic ice sheet. While most mountain ranges are eventually worn down by erosion or tectonic events, the Gamburtsev Mountains are preserved by a deep layer of ice, making it one of the best-preserved mountain belts on Earth. Mountains are formed by the collision of two tectonic plates and continue to change over time. The Himalayas are the biggest example after the Indian Plate and Eurasian Plate collided 50 million years ago. This range is rising even today, but Antarctica has been stable all this time, prompting the scientists to look for the secret behind it. According to a study published in the journal Earth and Planetary Science Letters, the mountain range first came into existence 500 million years ago when the Gondwana supercontinent formed from colliding tectonic plates. "The collision triggered the flow of hot, partly molten rock deep beneath the mountains," the authors wrote. "As the mountains continued to take shape, the crust thickened and heated, before becoming unstable and collapsing under their own weight." Other forces led the mountains to partially collapse as well. To further ascertain their hypothesis, the researchers turned to zircon, a mineral that acts like a geological stopwatch. These tiny crystals can survive for billions of years and contain uranium, which decays at a known rate, allowing scientists to determine their age with precision. These grains recorded peak mountain-building around 580 million years ago and the start of structural collapse by 500 million years ago. While gathering rock samples from the mountain remains difficult due to the logistics of drilling through the ice, the model developed by scientists offers new predictions about future exploration.
Yahoo
27-05-2025
- General
- Yahoo
Analysis of fossil teeth upends what's known about megalodon's diet, scientists say
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. What scientists understand about the voracious feeding habits of the colossal megalodon could be up for some revision. The prehistoric predator that went extinct about 3.6 million years ago was not hunting only large marine mammals such as whales as researchers widely thought, a new study has found. Instead, minerals in fossilized teeth reveal that megalodon might have been an opportunistic feeder to meet its remarkable 100,000-calorie-per-day requirement. 'When available, it would probably have fed on large prey items, but when not available, it was flexible enough to feed also on smaller animals to fulfill its dietary requirements,' said lead study author Jeremy McCormack, a geoscientist at Goethe University in Frankfurt, Germany. The study, published Monday in the journal Earth and Planetary Science Letters, also showed there were regional differences in the giant shark's feeding habits. The finding suggests megalodon would pursue whatever was in local waters, devouring other top predators and smaller prey alike. 'They were not concentrating on certain prey types, but they must have fed throughout the food web, on many different species,' McCormack said. While certainly this was a fierce apex predator, and no one else would probably prey on an adult megalodon, it's clear that they themselves could potentially feed on almost everything else that swam around.' Megalodon dispatched its prey with a ferocious bite and lethal, serrated teeth that could reach up to 7 inches (18 centimeters) long — the size of a human hand. The superpredator's teeth — abundant in the fossil record — are what McCormack and his colleagues used to conduct a geochemical analysis, unlocking fresh clues that could challenge megalodon's role as sole king of the ancient seas. It's not the first time that a study has challenged previous knowledge about the enormous sea creature. In fact, many questions remain unanswered about Otodus megalodon — its scientific species name meaning 'giant tooth' — since no complete fossil has ever been discovered. The lack of hard evidence stems from the fact that fish skeletons are made of softer cartilage rather than bone, so they don't fossilize very well. Recent research found that the animal was more warm-blooded than other sharks, for example, and there is an ongoing debate about its size and shape. Scientists who created a 3D reconstruction suggested in 2022 that megalodon was about three times as long as a great white shark — about 52 feet (16 meters). However, a March study hypothesized that the megashark was actually much larger — up to 80 feet (24 meters) in length and even longer than the fictional version in the 2018 blockbuster 'The Meg,' which suggested the ancient predator was 75 feet (23 meters) from head to tail. As for megalodon's feeding habits, determining what it ate based on fossil evidence poses challenges, according to McCormack. 'We know that they fed on large marine mammals from tooth bite marks,' he said. 'Of course, you can see bite marks on the bones of marine mammals, but you will not see them if they fed on other sharks, because sharks don't have bones. So there's already a bias in this kind of fossil record.' To glean more about megalodon's prey selection, McCormack and his coauthors looked at the giant shark's fossilized teeth and compared them with those of other animals that lived at the same time, as well as teeth from modern sharks and other predators such as dolphins. The researchers used specimens from museum collections and samples from beached animal carcasses. Specifically, the study team conducted a lab analysis of zinc, a mineral that is acquired only through food. Zinc is essential for living organisms and plays a crucial role in tooth development. The ratio of heavy and light zinc isotopes in the sharks' tooth enamel preserves a record of the kind of animal matter that they ate. Different types, or isotopes, of zinc are absorbed when fish and other animals eat, but one of them — zinc-66 — is stored in tooth enamel much less than another, zinc-64. The ratio between those zinc isotopes widens the further away an animal gets from the lowest level of the food chain. That means that a fish eating other fish would have lower levels of zinc-66 compared with zinc-64, and the fish that eat those fish will have even less zinc-66 compared with zinc-64, creating ratio markers that can help draw up a sequence of the food chain. The researchers found that sea bream, a fish that feeds on mussels and crustaceans, was at the bottom of their reconstructed chain, followed by smaller sharks from the Carcharhinus genus, up to 9.8 feet (3 meters) in length, and extinct toothed whales comparable in size to modern dolphins. Farther up were larger sharks such as the Galeocerdo aduncus, similar to a modern tiger shark, and occupying the top slot was megalodon — but its zinc ratios were not so different as to suggest a massive gap with the lower-tier animals, meaning they might have been part of megalodon's diet, too. 'Based on our new results, we see that it was clear it could feed at the very top, but it was flexible enough to feed also on lower (levels of the food chain),' McCormack said. In addition, the researchers found megalodon was not alone at the top of the food chain but instead shared the spot with other 'opportunistic supercarnivores' such as its close relative Otodus chubutensis and the lesser-known Araloselachus cuspidatus, another giant fish-eating shark. That revelation challenges the assumption that megalodon was the exclusive ruler of the oceans and draws comparisons with the great white shark, another large opportunistic feeder. The finding also reinforces the idea that the rise of the great white may have been a factor in megalodon's extinction, according to paleobiologist Kenshu Shimada, one of the coauthors of the latest study. 'One of the contributing factors for the demise of megalodon has been hypothesized to be the rise of the great white shark, which feeds on fish when young and shifts its diet to marine mammals as it becomes larger,' said Shimada, a professor of biological and environmental sciences at DePaul University in Chicago. 'Our new study, that demonstrates the 'diet overlap' between the great white shark and megalodon, strengthens the idea that the evolution of the smaller, likely more agile and maneuverable great white shark could have indeed (driven) megalodon to extinction.' The new research allows scientists to recreate a snapshot of the marine food web that existed about 20 million years ago, according to Jack Cooper, a UK-based paleobiologist and megalodon expert who wasn't involved with the study. 'The general picture of megalodon has been of a gigantic shark munching on whales,' Cooper said in an email. 'This study adds a new dimension that megalodon probably had a wide range of prey — essentially, it probably ate not just whales but whatever it wanted.' Another interesting find, he added, is that megalodon's diet probably varied slightly between different populations, something observed in today's great white sharks. 'This makes sense and is something we would have probably expected since megalodon lived all over the world and not all of its prey items would have done; but it's wonderful to have concrete data supporting this hypothesis,' Cooper said. The study adds to a growing body of evidence that is reshaping commonly held beliefs about megalodon and its close relatives, said Alberto Collareta, a researcher in the department of Earth sciences at Italy's University of Pisa who was not involved in the research. 'These have led us to abandon traditional reconstruction of the megatooth sharks as 'inflated' versions of the modern white shark. We now know that the Megalodon was something else — in terms of size, shape and ancestry, and of biology, too,' Collareta said via email. 'The Miocene (palaeo)ecosystems in question did not work in a radically different way compared to their modern counterparts — even if they feature … completely extinct protagonists such as the megatooth sharks,' he added, highlighting what he found to be the report's key takeaway. 'That said, it is still useful to acknowledge that our understanding of the Meg is essentially limited to its ubiquitous teeth, a few vertebrae and a handful of scales. What I'd really love to see emerging from 'the foggy ruins of time' is a complete Meg skeleton… Let's hope that the fossil record will amaze us once again.'
Time of India
26-05-2025
- Science
- Time of India
Scientists discover 14000-year-old solar storm which was so powerful that it could fry modern technology in seconds
Throughout history, our planet has been bombarded by solar storms, in the form of bursts of charged particles from the Sun that interact with Earth's magnetic field. Today as most of the world is dependent on technology and signals, even relatively mild space weather can disrupt satellites, power grids, and communications systems. But what if the worst is yet to be discovered, not in the future, but hidden in our distant past? In recent decades, scientists have grown increasingly interested in ancient solar activity. Unlike short-term observations from satellites, nature provides its own long-term record keepers, like tree rings and ice cores. These natural archives hold clues about the Sun's behaviour over thousands of years. Such discoveries not only help us understand our star's historical tantrums but also prepare us for the possibility of future solar storms that could cause massive disruptions to modern technology. The latest discovery has shocked the researchers. Evidence now points to a colossal solar storm that hit Earth over 14,000 years ago, and that storm was possibly far stronger than anything previously recorded, and powerful enough to severely impact today's global infrastructure if it were to happen again. In a study to be published in the July 2025 issue of Earth and Planetary Science Letters, researchers reveal that a solar storm around 12,350 BC left a dramatic carbon signature still visible today. This event, known as a "Miyake Event", named after Japanese physicist Fusa Miyake, who first identified such spikes in 2012, surpasses even the infamous 1859 Carrington Event, long considered the most intense solar storm in recorded history. Miyake Events are characterized by sudden surges in carbon-14, a radioactive isotope created when solar particles bombard Earth's atmosphere. This latest event was identified through tree ring samples from Scots Pines growing along the Drouzet River in France. The carbon-14 spike was validated by elevated beryllium-10 levels found in Greenland ice cores, indicating a truly global phenomenon. What sets this event apart, besides its sheer scale, is the timing. Occurring during the Ice Age, when Earth's atmospheric and magnetic conditions differed massively from today, and the signals were harder to interpret. To overcome this, scientists Kseniia Golubenko and Ilya Usoskin of the University of Oulu in Finland developed a specialized chemistry-climate model that accounted for ancient variables like sea levels, ice sheet positions, and geomagnetic fields. Their analysis revealed that this ancient solar storm unleashed a solar particle barrage 500 times stronger than the most intense storm recorded by satellites in 2005. As Usoskin explained, 'During the 2005 event, a passenger flying over the poles might have received a year's worth of cosmic radiation in one hour; during the Ice Age event, the same dose would have been delivered in just eight seconds.'
India Today
24-05-2025
- Science
- India Today
Blast from the Sun 14,000 years ago was so powerful trees still remember it
Scientists have uncovered evidence of a colossal solar storm that struck Earth more than 14,000 years ago, an event so powerful that its effects are still recorded in tree rings in the upcoming July 2025 issue of Earth and Planetary Science Letters, this ancient storm, which occurred around 12,350 BC, dwarfs any solar storm recorded in modern history and would wreak havoc on today's technology if it were to happen as a "Miyake Event," this storm far surpasses the infamous Carrington Event of 1859, previously considered the benchmark for extreme solar activity. Miyake Events are identified by spikes in carbon-14 levels found in tree rings—carbon-14 being a radioactive isotope produced when solar particles collide with Earth's atmosphere. Since the first discovery by Fusa Miyake in 2012, at least six such events have been confirmed, including those in 774 AD and 993 12,350 BC Miyake Event stands out due to its immense scale and the challenges it posed to scientists trying to interpret it. The spike in carbon-14 was detected in Scots Pine trees along France's Drouzet River, and corroborated by matching beryllium-10 levels in Greenland ice cores, confirming the storm's global interpreting these signals was complicated by the fact that the event occurred during the Ice Age, a period with very different atmospheric and climatic conditions compared to the relatively stable Holocene epoch when most other Miyake Events tackle this, researchers Kseniia Golubenko and Ilya Usoskin from the University of Oulu, Finland, developed a specialised chemistry-climate model. This model accounts for Ice Age variables such as ice sheet boundaries, sea levels, and geomagnetic fields, enabling accurate analysis of the ancient findings reveal that the 12,350 BC storm unleashed a solar particle bombardment 500 times stronger than the largest solar particle storm recorded by satellites in put this in perspective, during the 2005 event, a passenger flying over the poles might have received a year's worth of cosmic radiation in one hour; during the Ice Age event, the same dose would have been delivered in just eight discovery not only redefines the worst-case scenario for space weather but also opens the door to studying even older solar storms, potentially uncovering more extreme events hidden in Earth's ancient Watch
The Hindu
13-05-2025
- Science
- The Hindu
Data reveals birth of Antarctica's hidden mountain range 500 million years ago
Have you ever imagined what Antarctica looks like beneath its thick blanket of ice? Hidden below are rugged mountains, valleys, hills and plains. Some peaks, like the towering Transantarctic Mountains, rise above the ice. But others, like the mysterious and ancient Gamburtsev Subglacial Mountains in the middle of East Antarctica, are completely buried. The Gamburtsev Mountains are similar in scale and shape to the European Alps. But we can't see them because the high alpine peaks and deep glacial valleys are entombed beneath kilometres of ice. How did they come to be? Typically, a mountain range will rise in places where two tectonic plates clash with each other. But East Antarctica has been tectonically stable for millions of years. Our new study, published in Earth and Planetary Science Letters, reveals how this hidden mountain chain emerged more than 500 million years ago when the supercontinent Gondwana formed from colliding tectonic plates. Our findings offer fresh insight into how mountains and continents evolve over geological time. They also help explain why Antarctica's interior has remained remarkably stable for hundreds of millions of years. A buried secret The Gamburtsev Mountains are buried beneath the highest point of the East Antarctica ice sheet. They were first discovered by a Soviet expedition using seismic techniques in 1958. Because the mountain range is completely covered in ice, it's one of the least understood tectonic features on Earth. For scientists, it's deeply puzzling. How could such a massive mountain range form and still be preserved in the heart of an ancient, stable continent? Most major mountain chains mark the sites of tectonic collisions. For example, the Himalayas are still rising today as the Indian and Eurasian plates continue to converge, a process that began about 50 million years ago. Plate tectonic models suggest the crust now forming East Antarctica came from at least two large continents more than 700 million years ago. These continents used to be separated by a vast ocean basin. The collision of these landmasses was key to the birth of Gondwana, a supercontinent that included what is now Africa, South America, Australia, India and Antarctica. Our new study supports the idea that the Gamburtsev Mountains first formed during this ancient collision. The colossal clash of continents triggered the flow of hot, partly molten rock deep beneath the mountains. As the crust thickened and heated during mountain building, it eventually became unstable and began to collapse under its own weight. Deep beneath the surface, hot rocks began to flow sideways, like toothpaste squeezed from a tube, in a process known as gravitational spreading. This caused the mountains to partially collapse, while still preserving a thick crustal 'root', which extends into Earth's mantle beneath. Crystal time capsules To piece together the timing of this dramatic rise and fall, we analysed tiny zircon grains found in sandstones deposited by rivers flowing from the ancient mountains more than 250 million years ago. These sandstones were recovered from the Prince Charles Mountains, which poke out of the ice hundreds of kilometres away. Zircons are often called 'time capsules' because they contain minuscule amounts of uranium in their crystal structure, which decays at a known rate and allows scientists to determine their age with great precision. These zircon grains preserve a record of the mountain-building timeline: the Gamburtsev Mountains began to rise around 650 million years ago, reached Himalayan heights by 580 million years ago, and experienced deep crustal melting and flow that ended around 500 million years ago. Most mountain ranges formed by continental collisions are eventually worn down by erosion or reshaped by later tectonic events. Because they've been preserved by a deep layer of ice, the Gamburtsev Subglacial Mountains are one of the best-preserved ancient mountain belts on Earth. While it's currently very challenging and expensive to drill through the thick ice to sample the mountains directly, our model offers new predictions to guide future exploration. For instance, recent fieldwork near the Denman Glacier on East Antarctica's coast uncovered rocks that may be related to these ancient mountains. Further analysis of these rock samples will help reconstruct the hidden architecture of East Antarctica. Antarctica remains a continent full of geological surprises, and the secrets buried beneath its ice are only beginning to be revealed. Jacqueline Halpin is associate professor of geology, University of Tasmania. Nathan R. Daczko is professor of earth science, Macquarie University. This article is republished from The Conversation.
