Module 5 + Module 6 E&E Science Flashcards for half yearly

What did the Urey-Miller experiment simulate?

Early Earth atmosphere with methane, ammonia, hydrogen, and water vapor

Why was the Urey-Miller experiment important?

It demonstrated that the building blocks of life can arise from non-living chemical processes

Black Smoker Theory

Proposed that life on Earth originated around hydrothermal vents

Signficance of hydrothermal vents

They provided chemical energy needed for chemosynthetic organisms

Panspermia

The hypothesis that organic molecules or life were seeded to Earth via meteorites

What are stromatolites?

Layered sedimentary structures formed by cyanobacteria

Significance of stromatolites

They provide fossil evidence of early photosynthesis and oxygen production

Great Oxidation Event

A major increase in atmospheric oxygen due to photosynthesis by cyanobacteria

Impact of Great Oxidation Event

Allowed aerobic respiration and formation of the ozone layer

Significance of the ozone layer

Protected early life from harmful UV radiation, enabling colonisation of land

Key adaptations of plants to land

Waxy cuticle, stomata, vascular tissue, seeds, and roots

Significance of plant colonisation

It created terrestrial ecosystems and increased oxygen levels.

Key adaptations of animals to land

Lungs, limbs, waterproof skin, amniotic egg, internal skeleton, neck mobility

Supercontinent Cycle

The periodic formation and breakup of supercontinents over 400-600 million years

Impact of supercontinent formation

Causes climate change, extinctions, and biodiversity shifts

Why does continental drift drive speciation?

Geographic isolation leads to divergent evolution.

Law of superposition

Oldest rock layers are found at the bottom

Index Fossils

Widespread, short-lived fossils used to correlate rock layers

Why are fossils important?

They provide evidence of evolution and past environmental change

Mass extinction

A rapid and widespread loss of biodiversity.

Convergent Plate Boundary

Plates move toward each other; subduction often occurs.

Why are subduction zones explosive?

High silica magma traps gas, causing violent eruptions.

Divergent plate boundary

Plates move apart; magma rises to form basaltic crust.

Transform plate boundary

Plates slide past each other causing earthquakes.

Lahar

A fast-moving volcanic mudflow of ash and water

Impact of ashfall

Damages infrastructure, contaminates water, disrupts aviation.

What is a pyroclastic flow?

A fast, hot avalanche of gas and volcanic material.

Seismometer

An instrument that records earthquake waves.

What do tiltmeters measure?

Ground deformation caused by magma movement.

What does GPS monitoring measure?

Plate movement and strain accumulation.

Why is earthquake prediction difficult?

Fault rupture timing cannot be precisely determined.

What is mitigation?

Actions taken to reduce the impact of disasters.

Examples of mitigation

Building codes, hazard mapping, evacuation plans.

East Coast Low

An intense low-pressure system off Australia's east coast causing heavy rain and strong winds.

What are the hazards of East Coast Lows?

Flooding, coastal erosion, landslides.

Impact of climate change on hazards

Increases severity of extreme weather events.

Short term volcanic effects

Loss of life, ashfall, infrastructure damage.

Long term volcanic effects

Global cooling, reduced air quality, ecosystem change.

Why do people live near volcanoes?

Fertile soils, tourism, mining, cultural attachment.

Significance of Mt Pinatubo

1991 eruption caused global cooling due to sulfur dioxide aerosols

Impact of aerosols on climate

Reflect sunlight, causing temporary global cooling