Science Quarter 4 Review Notes

Plate Tectonic Theory

The Earth's crust is divided into large, rigid plates that float on the semi-molten layer of the mantle and are in constant motion.

Divergent Boundaries

Tectonic plate boundaries where plates move apart, leading to the creation of new crust.

Convergent Boundaries

Tectonic plate boundaries where plates collide, often resulting in mountain formation or subduction.

Transform Boundaries

Tectonic plate boundaries where plates slide past each other, commonly causing earthquakes.

Earthquake

A sudden shaking of the Earth's surface caused by the movement of tectonic plates.

Focus (Hypocenter)

The point underground where an earthquake starts.

Epicenter

The point on the Earth's surface directly above the focus of an earthquake.

Seismic Waves

Energy waves released during an earthquake that cause shaking.

Richter Scale

A scale that measures the magnitude or strength of an earthquake.

Mercalli Scale

A scale that measures the intensity or damage caused by an earthquake.

Volcano

An opening in the Earth's crust where magma, gases, and ash escape.

Active Volcano

A volcano currently erupting or expected to erupt in the near future.

Dormant Volcano

A volcano not currently erupting but may erupt again in the future.

Extinct Volcano

A volcano with no recorded eruptions in history.

Magma Chamber

The underground reservoir that stores molten rock in a volcano.

Vent

The opening in a volcano through which magma escapes.

Crater

A bowl-shaped depression at the top of a volcano.

Lava

Molten rock that has reached the Earth's surface during a volcanic eruption.

Rotation of Earth

The spin of the Earth on its axis, completing one full turn in 24 hours, causing day and night.

Revolution of Earth

The Earth's orbit around the Sun that takes approximately 365 ¼ days, causing the seasons.

The Sun

A massive star at the center of the Solar System that provides heat and light.