LAS VEGAS – The unique crystallized water, called Ice-VII, forms only at extremely high pressure like deep inside the Earth. Recently, researchers were looking for molecular forms of carbon dioxide in the Earth’s mantle when they stumbled across diamonds spewed from volcanoes and found traces of new water ice inside them.
The diamonds were collected at the depths of 410 and 660 km from transition zone in the mantle. This part of Earth’s interior is still poorly understood but new find suggests that water may have been freely flowing at such depths.
“Here, we provide evidence for the presence of aqueous fluid in regions of the TZ and around the TZ-LM boundary by showing the presence of ice-VII as inclusions in diamonds from these regions of the mantle. Ice-VII has recently been recognized as a mineral by the International Mineralogical Association.” Authors wrote in the study.
The discovery of Ice-VII in diamond is the first direct evidence of the presence of liquid water deep inside the Earth’s mantle. In other words, the new form of ice serves as an indicator for water-rich regions and can provide valuable clues to the inner workings of our planet because it is not possible to extract samples from very far below. The further we go down, the more intense the heat and pressure becomes.
“These discoveries are important in understanding that water-rich regions in the Earth’s interior can play a role in the global water budget and the movement of heat-generating radioactive elements,” said geoscientist Oliver Tschauner from the University of Nevada, Las Vegas. “It’s another piece of a puzzle in understanding how our planet works.”
Ice-VII represents a totally different type of water ice. It is about one-and-a-half times as dense as the regular ice we use in our drinks. Its atomic structure is also unique. In normal ice, oxygen atoms are arranged in the hexagonal structure. However, ice-VII arranges its atoms in a cubic shape.
