UNIT 4 — Earth Systems & Resources

What are the three main layers of the Earth's structure?

Core, Mantle, Crust

List three phenomena caused by plate tectonics.

Earthquakes, Volcanoes, Mountain building.

What is the best type of soil?

Loam.

What are the main components of soil?

Sand, silt, clay.

What does the 'O' horizon in soil horizons represent?

Organic matter.

What is the function of the troposphere?

It supports weather and life.

What is the significance of the stratosphere?

It contains the ozone layer.

How does climate differ from weather?

Climate refers to long-term atmospheric conditions, while weather refers to short-term conditions.

What do Hadley cells do?

They move heat from the equator to the poles.

What effect does El Niño have on the Pacific Ocean?

It warms the Pacific Ocean.

What impact does El Niño have on fish populations?

It decreases fish populations.

What percentage of Earth's water is saltwater?

97%.

What is the percentage of usable freshwater on Earth?

Only about 1%.

What is a major issue related to water resources?

Groundwater depletion.

What effect does La Niña have on the Pacific Ocean?

It cools the pacific ocean.

What impact does La Niña have on fish populations?

It increases fish populations.

A horizon

topsoil

B horizon

subsoil

C horizon

Parent material.