Science - Earthquakes 25.2

Plastic Deformation

Occurs high low stress, rock becomes permanently deformed.

Elastic Deformation

Occurs under low stress, rock returns to original shape once stress is released.

Tsunami

This is know as a seismic sea wave. They can be triggered by earthquakes.

Focus

What is the location where the "break" actually happens inside of the earth? Where the earthquake originates.

What do scientists use to study the shaking motion of earths crust?

Seismographs

Which two waves are considered body waves in an earthquake?

P waves and S waves

Which word best describes the force acting on crustal rocks?

Stress

Tension

Stress that pulls rocks apart in opposite directions

Surface waves

Seismic waves that are the most destructive

P waves

The fastest wave/arrive first

Seismograph

An instrument that records and measures an earthquake's seismic waves

Epicenter

The point on the Earth's surface (continental or oceanic) directly about an earthquakes starting point

Faults

The cracks in the Earth's crust along which movements that create earthquakes take place

S waves

Secondary waves

Ring of Fire

This feature marks the boundaries of the Pacific plate, where earthquakes and volcanoes are common

Focus

The point inside the Earth where the earthquake begins

P waves

A type of seismic wave that compresses and expands the ground. Move the fastest. Become Surface waves when they reach Earth's surface

Richter Scale

A numerical scale used to measure an earthquake's magnitude.

Triangulation

Using three distances waves travel to pinpoint the epicenter of an earthquake

Seismogram

The record of an earthquake's seismic waves production by a seismograph. (The print out from the machine)

Mercalli Scale

Measures the intensity of seismic activity

Earthquake

The shaking and trembling that results from movement of rock beneath Earth's surface

Epicenter

The surface location directly overhead of the focus of an earthquake