James O’Donoghue stood on the beach and pressed his toes into the soggy sand . Rough grains of sand tried to squeeze in between his toes, while the water being forced out of the Earth’s crust had submerged half of his feet.
The planetary scientist working at the Japan Space Agency (JAXA) wonders: What is right under my feet right now? Isn’t it the two elements that dominate most of the earth’s crust, where he and more than 7 billion other people live?
But kilometers deep into that crust, what other elements does the Earth have? And if he could peel the planet’s crust like an orange, what would it look like underneath the pulp?
It’s 2019 and James O’Donoghue has taken his questions to Dr. Christine Houser, a geophysicist and seismologist at Japan’s Institute of Earth Life Sciences. Houser immediately had an idea: He wanted to make a video illustrating the structure of the Earth’s crust, to show everyone how thin it is.
The earth is not really a green marble after its crust has been stripped.
“While we’ve had plenty of vivid images showing the Earth as a blue ball of water, there haven’t been any images showing its crust and underneath,” O’Donoghue told Business Insider. in an email.
And indeed, the Earth is not really a green marble after its shell has been stripped. Here’s a video demonstration by Drs Christine Houser and James O’Donoghue showing us what’s beneath our planet’s surface:
Although O’Donoghue is a planetary scientist, the information Dr. Houser shared still surprised him. ” The mantle of the Earth is green and I never knew it,” O’Donoghue said. ” Even though it’s very hot there, it’s not hot enough to make it burn red.”
The Mantle or Earth’s mantle that O’Donoghue refers to is a layer that separates the planet’s crust and core. Mantle is usually composed of rock or ice, and to Earth, it has a greenish color.
Above the mantle is the Earth’s crust, about 50km thick. For comparison, the ocean’s deepest point only cuts into a tenth of this crust, at about 5km. The main component of the Earth’s crust is silicon dioxide – also known as silica , a compound that makes up most of the world’s sand.
In addition, it contains 15.1% aluminum oxide, 6.1% calcium oxide, 4.9% iron oxide, 4.8% water, 4.5% magnesium oxide and 6.9% other compounds. . Even so, all the material in the crust combined makes up only 0.49% of the Earth’s mass.
O’Donoghue wrote on Twitter: ” Remember the surface of the Earth is the layer on which all (known) living things have ever lived “. That thin layer of rock and water is also the site of terrible earthquakes and where humans are cutting into the surface of the planet to extract minerals.
All that can surprise a planetary scientist like O’Donoghue ” is not the composition of the Earth’s crust (I know a little about them), it is actually the contrast between the magnitude of the Earth’s crust. its large compared to a fraction of the mass of the Earth. I think many others would be surprised at the absence of things like sodium and carbon, etc., which are common elements in our daily lives.” .
But the truth is that the elements of life are circulating throughout the Earth’s surface, from water, living things and the atmosphere, they make up only a very small part of the planet’s crust. We are only seeing less than 0.5% of the Earth, or our common home.