A vast ocean probably covered a third of the surface of Mars about 3.5 billion years ago., according to a new study by scientists at the University of Colorado (USA). The study is the first to combine the analysis of different structures related to water, including dozens of deposits caused by riverbed deltas and thousands of river valleys, to detect the presence of an ocean supported by a global hydrosphere on ancient Mars. .
Although the notion of a great ocean on Mars has been repeatedly challenged over the past two decades, the new research provides further support for the idea of a sustained sea on the red planet more than three billion years ago, the researcher explained University of Colorado Gaetano Di Achille, lead author of the study that publishesNature Geoscience.
More than half of the 52 river delta deposits identified by the researchers in the new study – each of which was fed by numerous river valleys – likely marked the limits of the proposed ocean, as they were all at roughly the same elevation. Twenty-nine of the 52 deltas connect to the ancient ocean of Mars, or the ocean’s water table, says Di Achille.
The study implies that ancient Mars probably had aEarth-like global hydrological cycle, which included precipitation, runoff, cloud and ice formation, and accumulation of groundwater.
Furthermore, Di Achille and his colleagues used a geographic information system to conclude thatthe ocean probably covered about 36 percent of the red planet with about 124 million cubic kilometers of water. With that amount, the ancient ocean would have formed the equivalent of a 550-meter deep layer of water spread across the entire planet. The volume of the ancient oceans on Mars would have been about 10 times less than the current volume of the oceans on Earth.
