Oceanographers Nunes and Norris investigate at the University of California the changes that have occurred in the deep sea rapids. These transformations are considered to be closely related to climate change and therefore can help to understand it better.
For current information, researchers have investigated the shell of a fossil called Foraminifera for two carbon isotopes --12 carbon and 13-. In fact, the longer the water takes in deep currents, the more carbon 12 appears in its composition. This is because most beings use carbon 12 in cell growth and, after their death, deep currents are enriched as they go deep. In several points of the Pacific and the Atlantic the proportions between these two isotopes have been measured, with this information a gradient has been developed that has served to observe the evolution of the currents in deep sea.
The conclusions of the research are clear. 55 million years ago sea currents underwent a major transformation, while the Earth was in a cycle of warming. The average ocean temperature then increased between 7 and 8 degrees Celsius. The research, therefore, will allow to analyze the current global warming.