A recent discovery challenges the conception of the appearance of early Earth. An international team of scientists revealed that billions of years ago, the oceans were not blue as they are today, but instead had an intense green color due to a radically different chemical composition.
The study, published in the journal Nature Ecology & Evolution, was based on advanced computational simulations that accurately reconstructed the environmental conditions of early Earth. These simulations included atmospheric variables such as elevated levels of water vapor and carbon dioxide, which increased the planet’s acidity and favored massive erosion that transported large amounts of iron into the seas.
The research focused on the effect of iron with a triple ionic charge in seawater. This element, when reacting with sunlight, absorbed blue wavelengths and allowed green light to reflect back into the atmosphere, giving the oceans a greenish hue. Thus, for an extensive period ranging from 3,000 to 600 million years ago, Earth would have appeared completely different from space.
Cyanobacteria, microorganisms that inhabited these ancient seas, played a crucial role in this phenomenon. Thanks to photosynthesis, these bacteria captured sunlight and transformed water into energy while releasing oxygen into the atmosphere. Over millions of years, this oxygen reacted with dissolved iron in the water, forming iron oxides that deposited on the ocean floor and reducing the iron concentration in the water. As a result, the seas began to adopt their characteristic blue color.
Implications of the discovery
This study not only changes our view of early Earth but also provides valuable clues about the evolution of marine ecosystems and the atmosphere. By understanding how the interaction between oceanic chemistry and biological activity shaped our planet, scientists could apply this knowledge in the search for life on other worlds.
The simulations include stunning visual recreations of the underwater environment of the Archean era, allowing us to imagine a planet very different from what is known today. With this discovery, researchers demonstrate the importance of a multidisciplinary approach to understand the processes that shaped Earth and its biodiversity.
Oceans
Does ocean water have a color?
The color of ocean water is blue, but it can vary depending on the location, time, and other factors. According to experts, ocean water is this color because it absorbs red, orange, and yellow hues, leaving the blues visible.
Furthermore, blue light has less chance of being absorbed and reaches greater depths, while the water’s surface reflects the color of the sky.
Have you visited our YouTube channel yet? Subscribe now!
