Earthquakes

What can cause an earthquake?

• Volcanoes

• Avalanches

• Asteroids

• Bombs

Answer explanation

All sorts of things that release energy can transfer to waves that travel through the ground - impact events, volcanos, avalanches, landslides, cave collapses, bombs.... even other earthquakes!

Tags

NGSS.MS-ESS3-2

NGSS.MS-ESS2-3

A seismologist studies

• Seismic waves

• Seizures

• Seismograms

• Ultrasound

Answer explanation

A seismologist is a type of geologist that focuses on seismic waves that are the source of an earthquake.

A seismogram is a recording of an earthquake.

A seismograph (or seismometer) is a machine that makes seismograms.

The release of energy between plates is halted by ___.

• volcanic eruptions

• mantle convection

• friction

• convergent boundaries

Answer explanation

Extreme pressure from both sides of a fault are forcing the two sides of rock together. This slow buildup of energy then 'slips', releasing all of the energy at once as seismic waves.

This grinding, fracturing, and pressure build up can create new types rock like breccia.

Tags

NGSS.MS-ESS2-3

The epicenter is the ___.

• first population zone that feels an earthquake

• first fault movement of an earthquake

• place where all wave types occur for an earthquake

• first surface movement of an earthquake

Answer explanation

A break in the lithosphere is a FAULT.

Friction builds, slips, and releases seismic energy at the FOCUS, often deep underground.

An EPICENTER is where an earthquake is first felt on the surface.

Tags

NGSS.MS-ESS3-2

Which seismic waves are underground as BODY WAVES?

• P Waves

• Love Waves

• S Waves

• Rayleigh Waves

Answer explanation

P waves (primary) stretches the Earth as it travels through solids and liquids.

S waves (secondary) move more slowly and at right angles; only able to pass through solids.

These body waves change their behavior once they reach the surface.

Tags

NGSS.MS-PS4-2

Which seismic waves are SURFACE WAVES?

• P Waves

• Love Waves

• S Waves

• Rayleigh Waves

Answer explanation

Surface waves move based on their original body waves from underground.

P waves turn into LOVE waves, which move side to side.

S waves turn into RAYLEIGH waves, which move up and down on the surface.

This three-dimensional movement can seriously damage surface structures.

Tags

NGSS.MS-PS4-2

How many seismographs are needed to TRIANGULATE an earthquake's origin

• 0

• 1

• 2

• 3

Answer explanation

TRI = 3

The GPS on your phone also triangulates your location using at least three satellites.

By drawing circles on a map, we can determine an earthquake's epicenter.

The MAGNITUDE of an earthquake refers to its ___.

• size

• strength

• epicenter

• focus

Answer explanation

There are several scales used to help define an earthquake.

A Richter Scale examines ground movement

A Moment Magnitude looks at the energy output at an earthquake's focus.

A Mercalli Scale observes noted damage caused.

Tags

NGSS.MS-ESS3-2

What are some secondary results from earthquakes?

• Tsunamis

• Aftershocks

• Liquefaction

• Seismic Gaps

Answer explanation

Aftershocks - a series of smaller quakes, bouncing down smaller fractures underground.

Tsunamis - P waves transform in the water to push aside more and more water until it reaches a shoreline.

Liquefaction - loose sediment and rock is rearranged suddenly.

Seismic Gaps - some areas along a fault line continue to build up pressure, resulting in less frequent but more violent quakes.

Tags

NGSS.MS-ESS3-2