Envi sci

• When was Earth formed?

  4.6 billion years ago
• During Earth's early years, volcanic eruptions released carbon dioxide, methane, and steam
• The Earth's inner core is made of solid nickel and iron
• Order the layers of the Earth from the center outward.

  1️⃣ Inner core

  2️⃣ Outer core

  3️⃣ Mantle

  4️⃣ Crust
• What are the five features of early Earth that made it suitable for life?

  Mass, magnetic field, rotation speed, axis tilt, distance from Sun
• Earth's mass creates a gravitational field that prevents gases from escaping
• What does the Earth's atmosphere ensure?

  Oxygen retention and suitable temperatures
• The Earth's magnetic field deflects charged particles released from the Sun.
• What are solar winds composed of?

  Charged particles
• The Earth's magnetic field is formed by convection currents in the outer core
• Why is the Earth's axis tilted by 23.5°?

  To regulate temperature and seasonality
• The Earth's rotation causes day and night cycles.
• What is the Goldilock Zone?

  The Earth's position in the solar system
• The Goldilock Zone ensures suitable temperature ranges and the presence of liquid
• What happens to metabolic proteins if temperatures are outside their tolerance range?

  They denature
• Incoming solar radiation is either reflected or absorbed by the Earth's surface.
• The reflectivity of a surface is known as its albedo
• Which type of surface has a high albedo?

  Snow
• Sequence the events of oxygen release and banded iron formation by cyanobacteria.

  1️⃣ Cyanobacteria release oxygen

  2️⃣ Oxygen combines with iron

  3️⃣ Iron oxide sinks to ocean floor

  4️⃣ Banded iron formations are created
• Banded iron formations are evidence of early oxygen release by cyanobacteria.
• Once all the iron was converted, oxygen began to exsolve into the atmosphere
• What molecule is formed from oxygen in the atmosphere that reduces harmful UV radiation?

  Ozone
• Ozone is formed by photolysis of diatomic oxygen molecules.
• What role does carbon sequestration by photosynthetic organisms play in the environment?

  Reduces atmospheric CO2
• Carbon dioxide is a powerful greenhouse gas that retains heat
• Match the biogeochemical cycle with its key process:

  Carbon cycle ↔️ Photosynthesis and respiration

  Nitrogen cycle ↔️ Nitrogen fixation

  Water cycle ↔️ Evaporation and precipitation
• Order the steps of the water cycle involving transpiration.

  1️⃣ Plants absorb water at their roots

  2️⃣ Water travels to leaves

  3️⃣ Water evaporates from leaves

  4️⃣ Water vapor returns to atmosphere

  5️⃣ Rainfall occurs
• What is the role of decomposers and detritivores in biogeochemical cycles?

  Release nutrients from dead organisms
• Transpiration by plants releases water vapor into the atmosphere.
• Why is historical climate data often unreliable?

  Technological limitations and gaps in data
• Proxy data provides indirect measurements of past climate
• What is dendrology used to study?

  Tree growth rings
• Thicker tree growth rings may suggest a warmer climate.
• Ice cores can be analyzed using gas bubble analysis or oxygen isotope analysis
• What does gas bubble analysis in ice cores measure?

  Composition of gases
• Match the proxy data method with its limitation:

  Tree growth rings ↔️ Affected by factors other than climate

  Ice cores ↔️ Uncertainty in dating

  Pollen grain analysis ↔️ Pollen distribution by wind
• Pollen grains are only preserved in wet environments.
• What is the purpose of satellites in climate monitoring?

  Collect data on a large scale
• Satellites collect data continuously with low manpower
• What does the GRACE satellite map?

  Variations in gravitational field