Answers
1. The earth’s outer layer or crust is broken into pieces called tectonic plates which are constantly moving towards, away from or past each other. Because continents are part of these plates, they also move. An earthquake occurs when the rocks break and move as a result of stresses caused by plate movements.
Most earthquakes occur on the edge of plates, especially where one plate is forced under another such as happens off Sumatra or past another as occurs in California. Some regions have more earthquakes than others with 80% of all recorded earthquakes taking place around the edge of the Pacific Plate, in New Zealand, Papua New Guinea, Japan, Canada, USA and South America.
2. The seismologists all over the world use a scale that measures the strength of volcanoes. This scale is called the Richter Scale. This scale measures from 0-10. Never has an Earthquake exceeded 9 on the Richter Scale. Also they use a seismometer. This instrument measures and records motions of the ground including seismic waves by earthquakes, nuclear explosions and other seismic sources.
3. The latest was Southern Alaska at 12.28 am United States time. On the 4/09/2008. It was at 60.101 Latitude, Longitude -152.742 and 100km deep.
4. The country of California is the country right on the fault line.
5. Because they measure where there is a change in the fault line at where the earthquake damaged the most at.
