February 28, 2010
Earthquakes have been happening for a long time, but now we are able to help detect where and possibly when these events might happen. They now seem to be getting stronger than they were in the past and even more frequent. No matter when or where earthquakes happen people always need to be aware that they have the potential to be devastating for those close by, or even those who are on the other side of the world.
Earthquakes happen several different ways and I will try to explain this. The Earth has different types of plate margins that can cause earthquakes. The first type of plate margin is called the ...view middle of the document...
This stress causes the Earth to rupture causing the earth to shake and quake. An earthquake happens when there is a build-up of stress in the earth’s crust caused by plate movement at a fault line of plate margin. The crust is a collection of crustal plates that move past, under, or over each other and then recede back. When the stress increases beyond the strength of the lithosphere rock this will cause a fracture, this fracture can cause an earthquake at these boundaries.
When pressure builds up along the fault lines and eventually slips, this sends out shock waves. The shock wave is the motion where the energy is transformed from the source of the earthquake to the surface of the Earth. An example would be if a person threw a rock into a pond or lake the ripples from the rock hitting the water would then spread out in all directions, so under the earth’s crust the energy from the magma trying to find a way to the surface causes movement of the tectonic plates and this is why the earth moves with quakes and shakes.
In 1935 Charles Richter created an instrument that is still used today to measure the magnitude of an earthquake; this device is called the Richter magnitude scale. The Richter scale is a logarithmic scale that measures ground movement with a seismograph and can calculate the magnitude of an earthquake by the height of the waves listed on the seismograph. Each whole number increase in Richter magnitude means that the ground motion of the quake is ten times the amount of the previous number.
Another type of measurement for earthquakes is the intensity scale. This is measured, in terms of...