×
Back left 6d79ffa2165c70419b5d81367025d889a832b878a14a24f303dd5f6f59a4f2c5
Back right 7131bbac0729874ea35f73598ddf94d2e1f7db07d23b55f12e0a2064353ff6d7

Earthquakes 101

April 28, 2015

SHARE IT!
LIKE IT!
kids articles

Thousands of earthquakes happen across the US each year. The good thing is, almost all of them are too small to feel. Most earthquakes in North America happen west of the Rocky Mountains, but there are still 39 states that are at serious risk for quakes.

Plate Tectonics

Our planet is divided into a three main layers: a solid core, a liquid magma mantle and a crust , which floats on top. That top crust is made up of individual plates, which are kept in constant motion by convection currents in the magma.

Tectonic PlatesTectonic Plates

Types of Plate Boundaries

Earthquakes mostly occur at the boundary where one plates meets another. Plates either converge, collide, diverge or move past each other when they meet. When plates "converge," it means that one plate is slowly pushed beneath the other over the span of several thousand years. Plates that collide push rock layers upward, which creates mountains. When plates move away from each other or "diverge," lava comes up from the mantle and cools to form new sections of crust. Other plates simply move slowly past each other.

Earthquake!

In some places, the plates become locked together. Energy builds up in the locked plates, which is released in the form of an earthquake when the plates finally give. The place where the earthquake originates beneath the surface is called the hypocenter. The point on the surface directly above the hypocenter is called the epicenter - a word you've probably heard many times in the news whenever a major earthquake is reported.

Ride the Waves

An earthquake emits its power as three waves of energy. Primary waves (a.k.a. P-Waves) are felts as a sudden jolt. Secondary waves (a.k.a. S-waves) arrive moments later and are felt as a more ongoing side-to-side shaking. Surface waves arrive after the main P and S waves, and radiate outwards from the epicenter.

Earthquake WavesEarthquake Waves

Recording Zigzags

A seismograph is a machine that records the ground vibrations during a quake. A needle keeps drawing straight lines until the earth trembles, then the lines start to zigzag. The bigger the zigzags, the bigger the quake. The strength of an earthquake is measured by the Richter scale. Based on the seismograph readings, the Richter scale rates a quake using numbers 0-9, nine being the mother of all quakes.

Home-Made SeismographHome-Made Seismograph

Earthquakes: The Richter Scale

  • 1: Generally not felt, except by instruments.
  • 2: Generally not felt, except by instruments.
  • 3: Sometimes felt by people, but no damage.
  • 4: Sometimes felt by people, but no damage.
  • 5: Felt by most people, damage near epicenter (where the plates actually smashed into one another).
  • 6: Damage to buildings within six miles (10 km) of the epicenter.
  • 7: Serious damage to buildings within 60 miles (100 km) of the epicenter. Loss of life.
  • 8: Major earthquake with damage being caused to a huge area. Loss of life over 120 miles (200 km).
  • 9: Very rare. Major damage and loss of life up to 600 miles (1,000 km) away.

The Richter ScaleThe Richter Scale

Are They Predictable?

So far, scientists have yet to develop a reliable way of predicting earthquakes. There are, of course, many factors that they believe lead up to earthquakes, like change in groundwater chemistry, foreshocks (small, insignificant quakes) and strain in underground rocks. Because each quake seems to be caused by a different combination of these factors, it makes it very difficult to make predictions far enough in advance to help people. Seconds before a quake, pets like dogs and cats might get a little freaky, as they seem to be able to feel the trembling well before we do.!

What To Do In An Earthquake

One of the biggest quake dangers is being hit on the head or trapped under something. If you are indoors, stay put. Place something protective on your head and crouch under a table or stand in a doorway. If you are outside, quickly find an open space and stay away from things that will fall on you. After an earthquake, be prepared for aftershocks. Aftershocks follow earthquakes and are usually smaller than the actual quake. They are dangerous because they can cause things that were weakened from the original earthquake to fall down.

Earthquake Preparedness KitEarthquake Preparedness Kit

For more information on earthquakes check out check out www.fema.com.

Related Stories

 

News Feed

To view your full News Feed please Login using your Username and Password or Register with Kidzworld!

Forum Activity

What instrument or instrume... in Everything Music posted by HeyItsTrashcan
What song is stuck in your ... in Everything Music posted by HeyItsTrashcan
First Period Storys. (Girls... in Girls Only posted by _agustduh
Write your best friend's na... in Say Anything posted by _agustduh
New site layout this week! in New Features on KW posted by James
How to make people like you... in School posted by saturn3
Would you Run,Ride a bicycl... in Everything Sports posted by saturn3
The movie start with the le... in Movies posted by saturn3
What would you do if you we... in Everything Music posted by saturn3
Write your best friend's na... in Say Anything posted by slurpie3
Sillyvision next Generation... in General Roleplays posted by Tord_Trash
Home For the Strange ( for ... in Private Roleplay posted by ThatGayGuy
What do you think i am?(hon... in Say Anything posted by nounou123
First Period Storys. (Girls... in Girls Only posted by WinxFanBloomKia231AP
Let's count to 1 Million! in Forum Games posted by rainbowpoptart
awnser the question the per... in Forum Games posted by rainbowpoptart
Rate the YouTube channel ab... in Forum Games posted by ImagineOrdinary
Write your best friend's na... in Say Anything posted by slurpie3
What song is stuck in your ... in Everything Music posted by ImagineOrdinary
New site layout this week! in New Features on KW posted by SnowflakeAngelKitten
New site layout this week! in New Features on KW posted by James
New site layout this week! in New Features on KW posted by SnowflakeAngelKitten
New site layout this week! in New Features on KW posted by rainbowpoptart
New site layout this week! in New Features on KW posted by simran88
New site layout this week! in New Features on KW posted by Abbergrl
New site layout this week! in New Features on KW posted by SnowflakeAngelKitten
what do you want to be when... in Current Events posted by Alois_Trancy_
New Real Time Private Messa... in New Features on KW posted by lolathedog
New Real Time Private Messa... in New Features on KW posted by Abbergrl
New Real Time Private Messa... in New Features on KW posted by ImagineOrdinary
Write your best friend's na... in Say Anything posted by _agustduh
Write your best friend's na... in Say Anything posted by slurpie3
Write your best friend's na... in Say Anything posted by slurpie3
What do you think i am?(hon... in Say Anything posted by H3LLSCRIVVER
What do you think i am?(hon... in Say Anything posted by fairytailfan123
What do you think i am?(hon... in Say Anything posted by TXSL9
What do you think i am?(hon... in Say Anything posted by ImagineOrdinary
What do you think i am?(hon... in Say Anything posted by nounou123
Know a good place to put my... in Random posted by ImagineOrdinary
Who is your celeb doppelgan... in Random posted by rainbowpoptart

Poll

F1155927837296
0

Disaster You'd Least Like to Get Caught In?