Water and Temperature Flashcards
Why are water and carbon important for life?
Water is crucial for cellular processes and comprises a significant portion of living organisms.
Carbon is central to organic molecules and climate stability
What is necessary for a planet to be habitable?
Capturing sufficient volatiles, including water, to form oceans and maintaining high surface concentrations of these volatiles.
How is the concentration of volatiles at Earth’s surface achieved?
Through mantle convection and impact degassing.
What do sedimentary rocks indicate about ancient water presence?
Weathering and transport by liquid water, as seen in the 3.8 Ga Isua formation in Greenland.
What insights do zircon minerals provide about early Earth?
Evidence of water and low-temperature water cycles dating back to 4.4 billion years.
How do stable isotope fractionation studies support the presence of ancient water?
Oxygen isotopes in zircons show evidence of interaction with water, indicating a water cycle as far back as 4.4 billion years.
What long-term processes affect the concentration of surface volatiles?
Cycling between Earth’s interior and exterior, impacts, core formation, and volcanic emissions.
How does Earth’s atmosphere lose volatiles?
Through thermal escape, solar wind particles, impacts, and high temperatures.
What role does subduction play in volatile recycling?
Returns volatiles to the mantle, balancing volcanic emissions and maintaining surface water budget.
Why is surface temperature stability important for Earth?
Essential for maintaining liquid water and supporting life over billions of years.
What factors determine Earth’s surface temperature?
Sunlight received, surface reflectivity (albedo), and greenhouse gases in the atmosphere.
How does Earth maintain a stable surface temperature?
Earth maintains a stable surface temperature through the balance of incoming solar radiation and outgoing thermal radiation, regulated by the greenhouse effect and the planet’s energy budget.
What is the faint young sun paradox?
The conflict between the low solar energy output of the early sun and evidence of abundant liquid water on early Earth.
What role does carbon dioxide play in Earth’s temperature regulation?
CO2 helps determine surface temperature through the carbon cycle involving atmospheric CO2 and calcium carbonate (CaCO3).
What are feedback loops in the carbon cycle?
Involving CO2 levels, temperature, rainfall, and acidity to maintain climate stability.
What can Venus teach us about climate regulation?
It exemplifies a runaway greenhouse effect resulting in extreme temperatures due to a CO2-rich atmosphere.
What is Snowball Earth?
Periods of complete glaciation during the Neoproterozoic, followed by rapid warming due to CO2 buildup and melting.
How does Earth’s atmosphere and magnetic field protect life?
The atmosphere, particularly the ozone layer, absorbs harmful UV radiation.
The magnetic field deflects charged particles like cosmic radiation.
Why is the ozone layer crucial for Earth’s habitability?
It absorbs much of the Sun’s harmful UV radiation, protecting life on the surface.
How is Earth’s magnetic field generated?
By convection in the liquid outer core, which diverts harmful particles from space.
