Earthquakes
Earthquakes are the world's most dangerous natural disasters. They can rip apart cities in a few minutes, tearing up everything in its path. Earthquakes are measured by something called a "Richter scale". A Richter scale was created by Charles Richter and Beno Gutenburg in 1935. This scale is a way of measuring an Earthquake. How the Richter Scale works, is it will take the rumble of the Earthquake and have a pen and a giant roll of paper that is spinning and then the pen would move back and forth on the paper. Now you would think, "So, the pen just moved on the paper, how does that tell us how big the Earthquake is." Well, there are marks on the Richter scale from 0.1-10.0, with 0.1 being the smallest, and 10.0 being the largest magnitude and Earthquake can have. However an Earthquake has never reached 10.0. The world's largest Earthquake's magnitude was 9.5 in Valdivia, Chile.
Seismic waves
Seismic waves are waves of energy that travel through the earth. There are three types of seismic wave Primary waves (P waves) Secondary waves (S waves) and Surface waves. These waves travel through the Earth at different speeds indiacating somewhere else in the world there is an Earthquake, Tsunami, or volcano happening.
Primary Waves
Primary waves (P Waves) travel faster than any other seismic waves of the other three. These waves are also called pressure waves and as I said before, These waves travel faster than any other wave. These waves travel through the Earth and come to Seismograph stations first, hence the name Primary. These waves travel through any type of liquid and solid material.
Secondary Waves
Secondary waves (S Waves) travel slower than the faster Primary waves. They will both arrive at the same station, carrying different details about the Earthquake. So the Secondary waves are slower probably because that they can only go through solids. Although liquids, such as thick substances and gases cannot have Secondary waves go through them. Secondary waves are 60% slower than Primary waves.
Surface Waves
Surface waves are the slowest seismic waves of them all. They are obviously called Surface waves because they travel along the Earths surface, as they cannot travel through and type of solid or liquid. These are probably the most destructive seismic wave. There are two tyoes of seismic waves: the Rayleigh wave, and the Love wave. Love waves travel faster than Rayleigh waves because of their high velocity. The Love wave's velocity is 90% of that of an ordinary Secondary wave.
Pacific Ring of Fire
Now if you have been studying up on earthquakes, you might have come across an area called "The Ring of Fire". Now what the ring of fire is, is well just an imaginary ring the runs across western North America (Canada, USA, Mexico, Central america) Western South America (Ecuador, Chile), Eastern and South Eastern Asia (Japan, Korea, Papua, Malasia, Philippines) and also the Pacific Ocean. This ring of fire has saw more earthquakes and volcanoes, than any other place in the world.
Dip Slip Fault
Now on this section, you will be learning about the three types of faults that occur when their is an Earthquake. This fault, which is called the Dip Slip Fault, could either be a normal fault, or a reverse fault. A Normal Fault Occurs when the Crust extends. A downthrown block betweeen two Normal Fault is called a Graben. Now on to the Reverse Fault which is the exact opposite of a Normal Fault. This happens when the hanging wall in the fault moves up relative to the footwall. The dip of a reverse fault is pretty steep, greater than 45°.
Strike Slip Faults
The Stike Slip Fault is the second type of fault you will be learning about. These type of fault move in a left-lateral formation. These type of faults are called the Snistral faults. Strike Slip Faults the move in a Lateral-right.
Oblique-slip Fault
A fault which has a half of dip-slip and a half of strike-slip is called an Oblique-slip Fault. Nearly all faults will have some parts of both dip-slip and strike-slip faults. So if you try to classify a Oblique-slip fault it will at least need to have componants of Strike-Slip Faults, and Dip Slip Faults