Researchers have discovered colossal fossilized mud waves, also known as sediment waves or contourite drifts, buried over 1,000 meters beneath the Atlantic Ocean floor off the coast of Guinea-Bissau, West Africa. These waves, reaching up to 300 meters in height and over a kilometer in length, provide insights into the Atlantic's formation and its connection to global climate patterns.
The discovery, supported by seismic data and core samples, refines our understanding of the Equatorial Atlantic Gateway, a geological junction between Africa and South America that emerged during the separation of the Gondwana supercontinent. The research indicates that the marine connection began approximately 117 million years ago, earlier than previous estimates.
This early connection triggered shifts in water circulation, leading to a submarine cascade that sculpted the mud waves. Initially, the opening contributed to temporary warming, but it later stabilized global ocean circulation, facilitating long-term cooling during the late Cretaceous period and playing a crucial role in global climate regulation. These findings, published in the journal Global and Planetary Change in June 2025, highlight the dynamic interplay between geological events and climate change.