What is an earthquake you might ask. Well, it is a violently shaking movement of the earth that is caused by the big blocks (plates) deep under the earth's surface. Earthquakes are really shaky and can be scary. If you get to know more about earthquakes you'll know what to do when one happens.
Where do earthquakes happen?
Earthquakes happen along faults. A fault is a peace of land that cracks along the ground. The San Andreas fault is a well known fault in California.
Describing The Different Types Of Waves
The different types of waves are primary waves (P waves) and secondary ways (S waves). The P wave comes before the S wave and can travel though solids, liquids, and gases. As P waves pass through a material, the particles of the material are slightly pushed together and pulled apart. The P wave can travel at about 5 km per second.
As S waves pass through a material, the material's particles are shaken up and down and from side to side. S waves cause more damage.
Well they are measured by things called seismographs. These seismographs are everywhere in the world measuring 24/7. They record every movement of the earth. When an earthquake happens, the seismographs will measured it. That is also how scientists find out how big an earthquake is.
Describing earthquake magnitude
A very powerful earthquake can release more energy than 1 million weak earthquakes combined. The earthquake magnitude scales give scientist and engineers a simple way to describe this huge range in energy. When the earth moves the scale draws little lines that tell the earthquake's magnitude. This scale is called the Richter scale. It was invented by two scientists in California during the 1930's. The scientists names were Charles Richter and Beno Gutenberg. The new versions of that scale are still being made today. The new scales are more accurate than in the past. The magnitude goes like this:
0-3.9 rarely noticed
4.0-4.9 slight damage
5.0-5.9 some structures damaged
6.0-6.9 major damage to structures
7.0-7.9 some well built structures destroyed
8.0 and above major to total destruction.
The different types of damage that earthquakes cause
The damage from an earthquake can be minor or severe depending on the size of the earthquake. Earthquake damage can include cracked roads and pipes. Buildings can be badly damaged or knocked down. The aftershocks are less powerful than the actual earthquake. There is another type of bad thing that happens after an earthquake happens. It is liquefaction. Liquefaction can be bad because it is like quicksand and can sink an entire building.
Earthquake safety tips
Get an earthquake safety kit. When there is an earthquake, you can be prepared.
Get an earthquake kit that will have enough food and water to last you three days. Don't get frozen food. It won't last long.
Identify a safe spot in your house so you will not get hurt.
Don't try to get to another building.
Call someone who lives in another town so they can tell people that you are safe and not dead or hurt.
Very good report!
ReplyDeleteHenry, that is very interesting! There is a big fault about 200 miles west of Nashville, called the New Madrid fault since it runs near the little town of New Madrid, Missouri. In 1811 and 1812 there were three magnitude-8 earthquakes along this fault. One of them shook the area so severely that the big Mississippi river ran backwards in one section several miles long. Some people think there will be another large earthquake there in the next few years.
ReplyDeleteYou did a wonderful job on your report!