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The Origin of the Ocean - Earth, Ocean, and Atmosphere Accumulated in Layers Sorted by Density

6 important questions on The Origin of the Ocean - Earth, Ocean, and Atmosphere Accumulated in Layers Sorted by Density

What is density stratification?

The important process that formed the Earth; which lasted about 100 million years ago. Due to gravity, heavier elements like Iron and nickel moved inwards of the planet, forming its core. Lighter elements as silicon, magnesium, aluminium and oxygen, formed the Earth's crust.

How did oceans become deeper?

They grew due to the rains that continued for 20 million years. Moreover, water vapor could escape the Earth during volcanic activity and also comets might have brought additional water to the Earth. Also, the Earth's crust grew thicker, probably because of the chemical reactions with oceanic compounds.

How can one estimate the age of objects, such as meteorites and rocks?

We know from signs of radiation within the objects that have fallen on the Earth, how long it has been since they were formed. Many of the objects were namely formed from the same time as the sun and planets and out of the same cloud. Together with the rate of radioactive decay of unstable atoms in meteorites, moon rocks and the oldest rocks on Earth, astronomers can make estimations.

Why is it difficult to find remnants of Earth's early surface?

Nearly all of that material has been recycled into our planet's interior. It is often possible to find information about the material of the crust when it was formed, dating back up to a couple billion years ago, however, the Earth's early surface has been made before that.

What was the composition of the early atmosphere?

It is believed the atmosphere was rich in CO2, nitrogen, water vapor and a bit of ammonia and methane. Starting around 3.5 billion years ago, this composition changed to the present one: mainly nitrogen and oxygen.

What is the oxygen revolution?

Around 1.5 billion years ago, ancestor plants started to use photosynthesis, which produced enough oxygen to oxidize in minerals dissolved in the ocean and surface sediments. Oxygen began to accumulate in the atmosphere.

The question on the page originate from the summary of the following study material:

Oceanography: An Invitation to Marine Science | 9781305480575 | Tom S Garrison

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