Latest news with #GlobalandPlanetaryChange
Time of India
12-08-2025
- Science
- Time of India
New study finds 117-million-year-old geological formations rewriting Atlantic Ocean history
Buried nearly a kilometre beneath the Atlantic seabed west of Guinea-Bissau lies a geological time-capsule: gigantic 117-million-year-old mud waves sculpted by dense, underwater avalanches. A new study published in Global and Planetary Change reveals that these ancient structures were formed when early Atlantic waters carved through the Earth's crust, much earlier than previously believed. This discovery reshapes our understanding of Atlantic Ocean formation, offers fresh perspectives on Cretaceous climate shifts, and provides clues to tectonic movements that governed our planet's evolving geography. From deep-sea sediment patterns to global carbon cycles, these mud waves, once hidden, now tell a story with far-reaching implications for modern geology and climate science. Underwater mud waves push the Atlantic's birth date back to 117 million years ago Recent research published in Global and Planetary Change (2025) by Duarte, Nicholson, and colleagues has shed new light on the early history of the Atlantic Ocean. Using a combination of modern seismic imaging and archived drilling data from 1975, the team identified a series of massive 117-million-year-old mud waves buried deep beneath the Atlantic seafloor. These geological giants, stretching over a kilometer in length and rising hundreds of meters high, were formed when dense, salty water from the young North Atlantic spilled into the deeper southern basins, creating powerful underwater currents. The composition and layering of these mud waves reveal that such flows occurred far earlier than previously believed, suggesting that the Equatorial Atlantic Gateway, the oceanic passage linking the northern and southern Atlantic opened sooner than most geological models predicted. This pushes back the estimated timeline of when the Atlantic became a fully connected ocean, making the discovery a crucial piece in reconstructing Earth's plate tectonic and oceanographic history. Not only does this finding refine our understanding of how and when the Atlantic took shape, but it also offers insights into the role of deep-water currents in shaping the seafloor over millions of years. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like This new air conditioner cools down a room in just seconds News of the Discovery Undo Sediment patterns illuminate early ocean currents and climate change The formation of these 117-million-year-old mud waves was far more than an isolated ocean-floor event, it represented a profound turning point in Earth's climate and geological history. When the young North Atlantic's saline waters finally breached into the long-isolated southern basins, they encountered dense, carbon-rich deep waters that had been locked away for millions of years. This sudden mixing unleashed colossal underwater mud avalanches, cascading across the seabed with immense force and reshaping the ocean floor's topography on a scale rarely seen in Earth's past. The consequences reached far beyond the geology. This tectonic–oceanic upheaval likely interrupted one of the planet's most important climate-regulating processes: the long-term burial of carbon in marine sediments. By disturbing these ancient, carbon-heavy layers, the event may have kept vast amounts of greenhouse gases circulating in the atmosphere, helping sustain the elevated global temperatures characteristic of the mid-Cretaceous, a period often referred to as one of Earth's 'greenhouse worlds.' Such persistent warmth not only influenced ocean chemistry and circulation but also shaped the evolution and distribution of marine life for millions of years afterward. Understanding precisely when the Equatorial Atlantic Gateway opened is therefore critical. It marks the moment the Atlantic transitioned from a series of isolated basins into a fully connected ocean, altering heat and nutrient flows on a global scale. By reconstructing this event, scientists can better model ancient ocean currents, climate feedback loops, and the deep-time mechanisms that still echo in today's climate system. In essence, these mud waves are not just relics of a vanished seafloor, they are a geological signature of the forces that have shaped, and continue to shape, Earth's climate trajectory. Why this discovery matters: from paleoceanography to climate modelling Knowing that the Atlantic began to take shape around 117 million years ago, evidence preserved in those colossal buried mud waves, significantly sharpens scientists' ability to model ancient ocean behaviour, tectonic shifts, and climate feedback loops. This revised timeline offers a clearer window into how early ocean gateways controlled the movement of heat across the planet, regulated carbon sequestration in marine sediments, and set the stage for long-term cooling or warming trends. By tracing these deep-time processes, researchers can better understand the intricate relationship between ocean circulation and Earth's climate system. Crucially, such knowledge is not confined to the past, it provides a framework for anticipating the effects of today's oceanic changes. From accelerating polar ice melt to shifting global currents, the same mechanisms that once shaped the Cretaceous world could, in altered form, dictate the trajectory of our future climate. Also read| Study reveals nature's hardest teeth: Chitons inspire future material design
Yahoo
14-05-2025
- Science
- Yahoo
Gigantic 'mud waves' buried deep beneath the ocean floor reveal dramatic formation of Atlantic when Africa and South America finally split
When you buy through links on our articles, Future and its syndication partners may earn a commission. The discovery of buried "mud waves" off the coast of western Africa reveals that the Atlantic Ocean was born at least 4 million years earlier than scientists previously thought. These waves, each hundreds of feet high and over half a mile (1 kilometer) long, were caused by the mixing of extremely salty water from the southern hemisphere with less-salty water from the northern hemisphere as South America and Africa tore apart 117 million years ago, forming the Atlantic, according to new research published in the June issue of the journal Global and Planetary Change. Previously, the Atlantic was thought to have finished opening between 113 million and perhaps 72 million years ago. The giant waves were found in sediment cores drilled from 0.6 mile (1 km) below the seabed about 250 miles (400 km) west of Guinea-Bissau in 1975, as part of the Deep Sea Drilling Project. The ocean-drilling project confirmed that Earth's surface is broken into rafts of ever-moving tectonic plates. Related: Sleeping subduction zone could awaken and form a new 'Ring of Fire' that swallows the Atlantic Ocean In further studying these cores, Heriot-Watt University geologists Débora Duarte and Uisdean Nicholson found evidence of huge mud waves in this region, which would have been the last spot to pull apart when Africa and South America split. "Imagine one-kilometre-long waves, a few hundred metres high: a whole field formed in one particular location to the west of the Guinea Plateau, just at the final 'pinch-point' of the separating continents of South America and Africa," Nicholson said in a statement. "They formed because of dense, salty water cascading out of the newly formed gateway." Before the Atlantic split South America and Africa for good, the final connection between the two continents would have been a series of deep basins, which were probably lakes, Duarte said in the statement. At that time, the South Atlantic was rich in salt deposits that made its water very saline, while the North Atlantic was less salty. This difference in salinity caused huge currents when the northern and southern Atlantic waters mixed. The currents, in turn, created the enormous mud waves along the seabed. Over the eons, more sediment has buried the waves, locking them below the surface. The existence of these waves 117 million years ago also suggests that the opening of the Atlantic caused Earth's climate to warm, Duarte said. RELATED STORIES —Atlantic ocean currents are weakening — and it could make the climate in some regions unrecognizable —Do the Pacific and the Atlantic Oceans mix? —Where do ocean currents come from? The basins that flooded in the final rifting of South America and Africa were rich in carbon, and the birth of the ocean would have made the sequestering of carbon less efficient. This reduced efficiency led to a period of warming between 117 million and 110 million years ago, the researchers said. After that, the ocean currents that circulate throughout the Atlantic stabilized, leading to a period of cooling. "This shows that the gateway played a really important role in global climate change," Duarte said in the statement.
Yahoo
13-05-2025
- Science
- Yahoo
Ancient 300-foot-tall mud waves gave rise to Atlantic Ocean
There was a time long ago when the Atlantic Ocean didn't exist. The general understanding among geologists is that the body of water originated between 83 to 113 million years ago, when South America and Africa split into their two respective continents to form the Equatorial Atlantic Gateway. However, Earth's marine history appears to require a multimillion-year revision thanks to a recent discovery roughly half a mile beneath the ocean floor. The evidence is explored in a study published in the June edition of the journal Global and Planetary Change. According to geologists at the UK's Heriot Watt University, gigantic waves of mud and sand sediment about 250 miles off the coast of Guinea-Bissau in West Africa indicate the Atlantic Ocean actually formed around four million years earlier than previous estimates. To understand just how intense all of this movement was, imagine waves that are about half a mile long and over 300 feet high. 'A whole field formed in one particular location to the west of the Guinea Plateau, just at the final 'pinch-point' of the separating continents of South America and Africa,' study co-author Uisdean Nicholson explained in a statement. Nicholson and their colleagues initially came across these layers of mud waves after comparing seismic data with core samples collected from wells during the Deep Sea Drilling Project (DSDP) of 1975. Five layers in particular were utilized to recreate the tectonic processes that broke apart the ancient supercontinent of Gondwana during the Mesozoic Era. 'One layer was particularly striking: it included vast fields of sediment waves and 'contourite drifts'—mud mounds that form under strong bottom currents,' said Nicholson. These waves initially formed as dense, salty water poured out from the newly created Equatorial Atlantic Gateway, 'like a giant waterfall that formed below the ocean surface,' he added. Just before the geologic event, huge salt deposits formed at the bottom of what is now the South Atlantic. After the gateway opened, the underground mudfall occurred when dense, relatively fresh Central Atlantic water in the north combined with very salty waters in the south. The resulting sedimentary evidence examined by the study's authors now indicates this opening seems to have started closer to 117 million years ago. 'This was a really important time in Earth's history when the climate went through some major changes,' explained study co-author Débora Duarte. 'Up until 117 million years ago, the Earth had been cooling for some time, with huge amounts of carbon being stored in the emerging basins, likely lakes, of the Equatorial Atlantic. But then the climate warmed significantly from 117 to 110 million years ago.' Duarte and Nicholson believe part of that major climatic change helped from the Atlantic Ocean, as seawater inundated the newly formed basins. 'As the gateway gradually opened, this initially reduced the efficiency of carbon burial, which would have had an important warming effect,' said Duarte. 'And eventually, a full Atlantic circulation system emerged as the gateway grew deeper and wider, and the climate began a period of long-term cooling during the Late Cretaceous period.' The ramifications go beyond revising Earth's geological timeline or the gateway's role in Mesozoic climate change. Better understanding the influence of oceanic evolutionary journeys on ancient climate patterns can help to predict what the future holds for the planet. 'Today's ocean currents play a key role in regulating global temperatures,' explained Nicholson. 'Disruptions, such as those caused by melting ice caps, could have profound consequences.'
Newsweek
08-05-2025
- Science
- Newsweek
Giant waves beneath the Atlantic reveal the ocean formed earlier than thought
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Scientists have discovered giant mud waves buried deep below the Atlantic Ocean around 250 miles off the coast of Guinea-Bissau, a country in west Africa. Made of mud and sand, these massive underwater sediment waves lie around 3,280 feet below the seabed, researchers reported in a new study. They were formed in the "Equatorial Atlantic Gateway"— the seaway that resulted from South America and Africa splitting apart, which created the Atlantic Ocean. The findings of the study, published in the journal Global and Planetary Change, suggest that the Atlantic Ocean may have formed millions of years earlier than previously thought, igniting a period of climate change. Using seismic data and cores from wells drilled as part of the Deep Sea Drilling Project in 1975, the researchers found five layers of sediment that they used to reconstruct the tectonic processes that divided the ancient continent of Gondwana in the Mesozoic era, when dinosaurs dominated the Earth. A stock image of an aerial view of waves in the Atlantic Ocean. A stock image of an aerial view of waves in the Atlantic Ocean. iStock / Getty Images Plus "This direct sedimentary evidence shows the establishment of a marine connection started at around 117 million years ago, significantly earlier than previous estimates, and coinciding with the onset of global climate cooling," the researchers wrote. "These findings show the dynamic interplay between gateway opening, ocean circulation and climate change during the middle Cretaceous [period], highlighting the pivotal role of ocean gateways in Earth's climate system," the researchers added. One striking layer of sediment included vast fields of sediment waves and "contourite drifts," which are mud mounds that form under strong bottom currents, noted Uisdean Nicholson, one of the two geologists from the School of Energy, Geoscience, Infrastructure and Society who discovered the waves. "Imagine one-kilometer [around 3,280 feet]-long waves, a few hundred meters [around 328 feet] high—a whole field formed in one particular location to the west of the Guinea Plateau, just at the final 'pinch-point' of the separating continents of South America and Africa," Nicholson said in a statement. These waves were formed from the strong contrast in density between the fresh waters of the open Central Atlantic waters in the north and the salty waters in the south. The dense, salty water spilled out from the newly formed gateway, Nicholson said. He added: "Think of it like a giant waterfall that formed below the ocean surface." The researcher explained: "Just before this time, huge salt deposits were laid down in the South Atlantic. When the gateway opened, fresh water poured into these narrow basins, and the denser, more saline water flowed out to the north, forming these giant waves." The study's findings put a new date on the opening of the Equatorial Atlantic Gateway and its impact on climate regulation. The gateway was previously believed to have opened between 113 and 83 million years ago. However, the discovery of the sediment waves indicated that the opening began earlier: from around 117 million years ago. Paper co-author and geologist Débora Duarte explained that up until 117 million years ago, the Earth had been cooling for a while, with vast amounts of carbon stored in most likely lakes and other emerging basins of the Equatorial Atlantic. "But then the climate warmed significantly from 117 to 110 million years ago," Duarte said in a statement. "And we think that this was likely because of the first connection through this gateway and the inundation of seawater into these emerging basins." The efficiency of carbon burial was initially reduced as the gateway opened, which would have had a warming effect. A full Atlantic circulation system was formed as the gateway grew deeper and wider, and the climate entered a period of long-term cooling during the Late Cretaceous era. "This shows that the gateway played a really important role in global climate change during the Mesozoic," Duarte noted. "Understanding how past ocean circulation influenced climate is crucial for predicting future changes," Nicholson said, adding: "Today's ocean currents play a key role in regulating global temperatures, and disruptions, such as those caused by melting ice caps, could have profound consequences." Do you have a tip on a science story that Newsweek should be covering? Do you have a question about geology? Let us know via science@ Reference Duarte, D., Erba, E., Bottini, C., Wagner, T., Aduomahor, B., Jones, T. D., & Nicholson, U. (2025). Early Cretaceous deep-water bedforms west of the Guinea Plateau revise the opening history of the Equatorial Atlantic Gateway. Global and Planetary Change, 249.
