Earth and Space Science Flashcards

Which layer of Earth is made of liquid iron and nickel, and its movement produces Earth's magnetic field?

Answer: Outer core

The outer core is liquid iron and nickel. As this metal moves (convection), it produces Earth's magnetic field. The inner core is solid because of extreme pressure.

What mainly causes the seasons on Earth?

Answer: The tilt of Earth's axis as it orbits the Sun

Earth's axis is tilted about 23.5°. As Earth orbits, each hemisphere takes turns leaning toward the Sun, getting more direct sunlight and longer days. That is summer. Distance is not the cause: Earth is actually closest to the Sun in January.

Granite forms when magma cools slowly deep underground. What type of rock is granite?

Answer: Igneous

Igneous rocks form when magma or lava cools and hardens. Granite is an intrusive igneous rock. It cools slowly underground, which lets large crystals grow.

Most earthquakes and volcanoes happen in which places?

Answer: The boundaries between tectonic plates

Earth's lithosphere is broken into tectonic plates. Where plates collide, pull apart, or slide past each other, stress builds up and magma can rise, so earthquakes and volcanoes cluster there. One example is the Pacific 'Ring of Fire', which includes British Columbia's coast.

Which process in the water cycle turns water vapour into liquid droplets that form clouds?

Answer: Condensation

In condensation, water vapour cools and turns into tiny liquid droplets, which group together as clouds. Evaporation is the opposite (liquid to gas), and precipitation is water falling back to Earth.

Why does the Moon seem to change shape (go through phases) over about a month?

Answer: We see different amounts of the Moon's sunlit half as it orbits Earth

The Sun always lights half of the Moon. As the Moon orbits Earth, we see more or less of that lit half, which creates the phases. Earth's shadow only falls on the Moon during a lunar eclipse.