Dr. Débora Duarte and Dr. Uisdean Nicholson have uncovered a fascinating and new discovery. If they’re right, their findings would turn upside down how scientists understand the creation of the Atlantic Ocean. Their research dated these sediment waves at 117 million years old. These waves rest roughly one kilometer under the seabed, a sign that the opening of the Equatorial Atlantic Gateway started significantly earlier than scientists had thought. This gateway opened up when South America and Africa tore apart. Such insights are critical for the formation of today’s Atlantic Ocean.
Sediment waves, like the ones shown here, made of mud and sandy sedimentary deposits are important harbingers. They prove that geological processes related to the birth of the Atlantic Ocean began much earlier than previously accepted. These discoveries provide thrilling new insights into the inauguration of this vital trade route. They’re a treasure trove of insights into what happened to climate regulation behind the scenes in that era.
Implications of the Findings
Scientific studies suggest that the Equatorial Atlantic Gateway first started to open around 117 million years ago. This new finding upends previous widely held assumptions that this event occurred between 113 and 83 million years ago. Dr. Duarte emphasized this revelation, stating, “The consensus has been that the gateway opened between 113 and 83 million years ago. The sediment waves show that the opening started earlier, from around 117 million years ago.”
The timing of this earlier opening had major consequences for global climate at the time. As Dr. Nicholson explains, “Figuring out how ocean circulation has shaped past climate is the key to predicting how it will shape the future of our planet. Today’s ocean currents play an important role in controlling the earth’s global temperatures. These tipping points, such as the melting of our ice caps, can have catastrophic effects.
To conduct their study, the researchers used seismic data and cores from wells drilled in 1975 during the Deep Sea Drilling Project (DSDP). In the process they isolated five distinct layers of sediment. These meticulously stacked layers painted a beautiful picture of the tectonic processes that ultimately rifted apart the ancient continent of Gondwana.
Geological Features of the Discovery
Yet what Dr. Duarte and Dr. Nicholson found were enormous sediment waves — of a kilometer in length. These massive hoodoo structures reach heights of several hundred meters, creating otherworldly landscapes. An impressive field develops in a relatively small area west of the Guinea Plateau. This location represents the last known “pinch-point” where the continents of South America and Africa started to break apart.
Dr. Nicholson described this striking feature: “Imagine one-kilometer-long waves, a few hundred meters 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.” He further elaborated on how these sediment waves formed: “They formed because of dense, salty water cascading out of the newly formed gateway. Imagine it as a huge underwater waterfall created at the bottom of the ocean.
This new study demonstrates that sediment waves provide unequivocal evidence of ocean currents. These currents are maintained by a strong density contrast between the relatively “fresh” waters of the Central Atlantic and the hyper-salty waters to the south. This density difference helped to drive the primary patterns of ocean circulation that are structured within the geological timescale.
Climate Effects and Future Research
In that vein, researchers were surprised to find how dramatic the climate shifts were between 117 and 110 million years ago. That all changed with the 2018 opening of the Equatorial Atlantic Gateway. This era represents a long-term warming trend which may be linked to changes in oceanic circulation and/or background environmental conditions.
Figuring out these ancient processes are key to understanding today’s climate, dynamic. Dr. Nicholson emphasized the need to learn from history. This research offers new understanding of how similar shifts would impact today’s vastly different climate system.
Since then, this study has increased our understanding of the Atlantic Ocean’s geological history. Contained within it is an emphasis of the critical role that oceanic processes are playing in climate regulation across Earth’s history.