It is indeed ironic that our planet is named Earth, even though the majority of its surface is covered in water. In fact, 70% of the Earth’s surface is covered by the ocean. However, scientists were shocked to discover an even larger body of water hidden beneath our feet! In 2014, scientists from Northwestern University in Illinois made this groundbreaking discovery, altering our understanding of the Earth’s interior.
Theories have long debated the origins of Earth’s water. Was it through the impacts of icy comets or an internal process? Steven Jacobsen and his team uncovered a massive reservoir of water within the Earth’s mantle, hidden 700 kilometers underground. This reservoir is estimated to be three times larger than all the water on the Earth’s surface.
The team used seismometers to measure seismic waves generated by earthquakes and found evidence of water deep within the Earth’s mantle. The water is trapped in a blue rock called ringwoodite, which acts as a sponge and can hold up to 1.5 percent water. This discovery suggests a whole-Earth water cycle that could rewrite what we know about water on our planet.
While the comet theory lost favor after this discovery, new data from 2018 shows similarities in the composition of water found in comets and Earth’s oceans. The discovery of an underground ocean challenges our understanding of the planet’s water cycle and its origins. Scientists continue to gather seismic data globally to confirm if this underground ocean is a global phenomenon. Earth’s geological history may hold many more mysteries waiting to be uncovered.
