Recreating the deepest point on Earth

Scientists from Rome Tor Vergata and ISIS have used the Vesuvio spectrometer to unravel part of the mystery behind the physical and chemical conditions of the Mariana Trench – one of the most extreme environments in the world.

​​​The Mariana trench​
Credit: ​​1840489pavan nd, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons​

While we’ve been successful with space missions to the Moon and climbing expeditions up Mount Everest, fewer people have been able to descend to the deepest point on Earth: ‘Challenger Deep’ in the Mariana Trench. The name in itself suggests how difficult it is to study the crescent shaped ‘scar’ that cuts across the ocean floor.

 

Since 70% of the Earth is engulfed by the oceans, it’s not surprising that we’re drawn to studying them in the context of marine biology, climate change and so much more. Researchers from Tor Vergata University of Rome, ISIS and ISIS@MACH ​designed an experiment that enabled them to recreate the conditions of Challenger Deep on the Vesuvio spectrometer at ISIS.

 

Using deep inelastic neutron scattering (DINS) they were able to measure the kinetic energy of the hydrogen atoms in the water under these conditions. Compared to normal seawater, the water in the trench is at a much higher pressure and holds considerably more salt.

 

They found that the higher pressure and salinity have competing effects on the mean kinetic energy values of the hydrogen nuclei, with the higher pressure increasing the energy, and the salinity decreasing it. These changes impact the fraction of hydrogen in the water that is found as deuterium.

 

​​Understanding the extraordinary conditions in environments like that of the Mariana Trench brings us one step closer to explaining the adaptation of bacteria and other life forms that thrive in high pressure environments. Furthermore, using high energy neutrons to take measurements on ISIS instruments like VESUVIO play a crucial role in pushing forward research that explains the quantum mechanical effect of water.

 

Further Information:

The full paper can be found here: https://doi.org/10.1063/5.0021926​