Grade 8 2nd Quarter Reviewer

Comprehensive practice vocabulary flashcards covering Earthquakes, Light Physics, and Celestial Bodies (Comets, Asteroids, and Meteors) based on the 2nd Quarter Reviewer.

Earthquake

The sudden shaking or movement of the Earth's crust due to the rapid release of energy.

Epicenter

The spot on the surface of the earth directly above the focus.

Fault

A break on the earth's crust along which significant movement has taken place.

Reverse faults

Faults that are formed when rocks are compressed.

Modified Mercalli Scale

A scale that measures an earthquake's intensity based on the observed effects on people and structures.

Focus

The place where an earthquake starts or where the slip is initiated.

PHIVOLCS

The government agency in the Philippines tasked to identify earthquake intensity and monitor crustal movement.

Pacific Ring of Fire

The location along which the Philippines is situated, making it prone to earthquakes.

Refraction

The bending of light when it travels from one medium to another of different optical densities.

Reflection

The phenomenon that occurs when light strikes a mirror.

Red

The least bent color in the spectrum, which also has the greatest wavelength and least energy.

Speed of Light

The constant speed in a vacuum, which is $3 \times 10^8\,\text{m/s}$.

Light

An electromagnetic wave located between the spectrum of infrared and ultraviolet.

Dispersion

The phenomenon observed when white light enters a prism and separates into different colors.

Stick and slip

A process where rocks are stuck together due to friction and then suddenly slip, generating an earthquake.

Tsunami

A series of ocean waves generated by sudden displacements in the sea floor, landslides, or volcanic activity.

Seismic waves

Waves of energy that travel through the Earth's layers.

Active fault

A fault that has displayed seismic activity.

Tropical Cyclone

A weather system that forms over warm ocean water with temperatures of about $26.5^{\circ}\text{C}$ or more.

Comets

Icy bodies that usually come from the Kuiper Belt or Oort Cloud and have highly elliptical orbits.

Asteroids

Rocky fragments mostly found in the belt between Mars and Jupiter.

Halley's comet

The most famous short-period comet of the 20th century, which appeared in 1910 and 1986.

Asteroid 2012 DA14

The asteroid that orbitally passed close to Earth on February 16, 2012 (Philippine time).

Meteor shower

An event that occurs when Earth orbits the Sun and passes through the orbit of a comet.

Shooting star

A common name for meteoroids burning up in the Earth's atmosphere.

Gas tail

The part of a comet that always points away from the sun.

Meteoroid

A space rock fragment before it enters Earth's atmosphere.

Meteor

The light phenomenon observed when a space rock fragment enters the atmosphere and burns up.

Meteorite

A space rock fragment that survives the atmosphere and lands on Earth's crust.