Scientists have studied traces of past microbial life in sediments off the coast of Peru. These fragments reveal how the microbial ecosystem under the seafloor has responded to climate change over hundreds of thousands of years.
The research project
has been taking place over the past ten years into what is known as the ‘deep biosphere’, the very depths of the great oceans. The reason that microbes are so revealing is because microbial life influences the cycling of carbon in the oceans, and scientists can measure carbon changes over time. Another area examined are the levels of methane (microbes utilize the energy of methane, which they oxidize by using sulphate). Such studies are called ‘palaeoceanograpy’.
In order to obtain samples, the scientists used the Integrated Ocean Drilling Program (IODP). The IODP
is an international marine research program. The program uses heavy drilling equipment mounted aboard ships to monitor and sample sub-seafloor environments. With this research, the IODP documents environmental change, Earth processes and effects, the biosphere, solid earth cycles, and geodynamics.
IODP gives scientists the opportunity to:
Recover geological records and rock samples;
Investigate and document ocean- and climate-change through time;
Explore the presence of primitive life below the seafloor;
Verify remote, near-seafloor observatories;
Gain understanding of how tectonic plates move and recycle themselves into the deep mantle.
The results have yet to fully analysed, but they are expected to reveal the changing climate of the planet over long periods of time.
The project is a collaboration between the Max Planck Institute for Marine Microbiology and their colleagues at MARUM and the University of Aarhus. The results have been published
in the journal of the Proceedings of the National Academy of Sciences. The paper is titled “Cyclic 100-ka (glacial-interglacial) migration of subseafloor redox zonation on the Peruvian shelf.”