Intro to the Earth system

Question 1

What are the 5 spheres?

Answer 1

Hydrosphere, Cryosphere, Geosphere, Biosphere and Atmosphere

Question 2

Define ‘Geochemical cycles’.

Answer 2

The cycles of mass between the different Earth spheres.

Question 3

Define Rheological processes.

Answer 3

The study of flow and deformation of matter.

Question 4

Explain why energy and mass transfer from one reservoir to another.

Answer 4

Energy and mass transfer between reservoirs in a (bio)geochemical cycle due to natural processes that maintain equilibrium and sustain life on Earth. These transfers happen because of physical, chemical, and biological mechanisms that facilitate the movement of elements and energy across different spheres.

Question 5

Define the rock cycle and outline the principal controls that drive it.

Answer 5

The rock cycle the process through which rocks are transformed between the three main types. It involves the formation, breakdown, and reformation of rocks through geological processes such as cooling, weathering, erosion, compaction, and heat and pressure over millions of years. The principal controls are:
-Heat from Earth’s Interior
-Plate Tectonics
-Weathering and Erosion
-Hydrological Cycle
-Gravity

Question 6

Define and give examples of a positive and negative feedbacks in Earth’s climate system.

Answer 6

A feedback in Earth’s climate system is a process where a change in one component triggers changes in other components, which can either amplify (positive feedback) or dampen (negative feedback) the initial change.
Examples: Ice-Albedo Feedback and Cloud Formation Feedback

Question 7

Describe the evolution of the Earth’s atmosphere and the origin of its principal components.

Answer 7

Primordial Atmosphere: Formed during Earth’s early formation through the accretion of gases from the solar nebula. (Hydrogen and Helium)

Secondary Atmosphere: Developed through intense volcanic outgassing from Earth’s interior.
(Water vapor (H₂O), Carbon dioxide (CO₂), Nitrogen (N₂), Sulfur dioxide (SO₂), methane (CH₄), and ammonia (NH₃))

Early Oxygenation: Initiated by photosynthetic cyanobacteria that began producing oxygen (O₂) through photosynthesis. (GOE 2.5Ga)

Question 8

Offer hypotheses that explain the Faint Young Sun Paradox.

Answer 8

The Faint Young Sun Paradox describes a contradiction between the early Sun’s expected luminosity and evidence of warm, liquid water on the early Earth.

1. Higher Greenhouse Gas Concentrations (carbon dioxide and methane)
2. Lower Albedo (less land)
3. Different models for the evolution of the sun.