Early Atmosphere

Flashcards reviewing key concepts related to the early atmosphere and the Great Oxidation Event.

What evidence constrains what the atmosphere was like in the Archean?

Fluid inclusions, 36 argon, and fossil record imprints give us constraints. Fluid inclusions and 36 argon suggest a partial pressure of nitrogen at less than one bar. Physical volumes in a single basalt flow suggest a total atmospheric pressure of about 0.23 bar. Fossil record imprints suggest a limit of 0.52 to 1.2 bar.

Why is CO2 important?

It is a greenhouse gas that controls the ocean pH.

What are methanogens?

Methanogens are bacteria that produce methane.

What information can be gathered from sulfur production?

Sulfur production, requiring a certain amount of UV to exist, which implies not much ozone, hence low oxygen.

According to the 2023 paper, what does a self-consistent thermodynamic model help determine?

Earth's water formed, how core densities may be affected, and its oxidation state.

What hydrogen level did the twenty twenty three paper assume when building their model for the early Earth?

An initial hydrogen atmosphere composition of about 0.2%.

According to the 2023 paper, how did hydrogen interactions impact Earth's water?

Hydrogen interacts in with metal phases where this interaction has an inverse correlation between the incorporation of hydrogen to the metal phase and the portion of H2O that you put into the back of the atmosphere. With a budget of 1.2 hydrogen atmosphere, you can get about volume of earth's threshold oceans.

What is hydrogen escape?

Due to high and mid lights, it can escape up the magnetic pole lines and leave our answer. This loss will, yeah, shift as we reduce the answer to a more oxidized one in which oxygen is stable.

What occurs at the GOE?

A steady loss of xenon and hydrogen, which then reach a critical mass out of the oxidation of the surface levels, and then the pumping out of oxygen, bio, cyanobacteria is enough to build itself up and create this which is very simple to the one today.

What is the evidence for the GOE (Great Oxidation Event)?

Mass fractionation disc shows oxygen, oxygen can survive in oxygen free environments, so their change, red beds, multicellular life