New research reveals that immense amounts of water exist far below the Earth’s surface, hidden in the depths of the mantle. This groundbreaking finding transforms our understanding of geological processes inside the planet.
Water’s Role in Geological Activity
Studies show there is water located up to 1,000 km down in the mantle, in its deepest layers. Dr. Mainak Mookherjee, who led one study, explains water is vital for mantle convection. This involves solid rock flowing from hotter to colder mantle regions over geological timescales.
Without water, convection would be ineffective and eventually halt. Convection drives plate tectonics and creates volcanoes, which generate the Earth’s crust where we live. So without convection, crust formation would stop, freezing planetary processes.
The notion of deep mantle water first arose in 2014 when diamonds containing hydrous minerals from the mantle were found. These flecks formed hundreds of km underground, providing rare glimpses inside Earth. The water is not liquid but hydrogen and oxygen atoms within the minerals’ crystal lattice.
The Crucial “Transition Zone” Between 410-660 km
Researchers identify the mantle “transition zone” between 410-660 km down as the key location for hydrous minerals. Situated between the upper and lower mantle, minerals here like wadsleyite and ringwoodite can store and release water when melted.
Experiments show these transition zone minerals may contain up to 1-3% water by weight. Given the zone’s immense thickness and Earth’s mass, it could hold several times more water than Earth’s oceans. Seismic data revealing water-friendly minerals points to a gigantic underground reservoir.
Some diamonds even encapsulate actual water ice, proving water exists deeper than thought. This leads to the question – how did so much water get down there? The common view is Earth’s water arrived via water-rich objects like asteroids. But a transition zone reservoir challenges this idea.
Theories suggest water stuck to particles during Earth’s formation, meaning at least some interior water has always been present.
Unlocking Earth’s Inner Mysteries
Much remains unknown about mantle water. Scientists are exploring its nature and extent using mantle electrical conductivity and more hydrous mineral diamonds.
The revelation of huge amounts of water within the mantle revolutionizes our comprehension of Earth’s geology. This hidden source shows the intricate links between surface volcanism and inner dynamics, making our planet even more fascinating.
