Why do earthquakes most of the earthquakes of the U.S. occur in California?

Answer 1

Because a major faultline runs through California, the San Andreas fault.

Answer 2

Actually, Alaska has far more earthquakes than any other state. The earth's most active seismic feature, the circum-Pacific seismic belt, brushes Alaska and the Aleutian Islands, where more earthquakes occur than in the other 49 States combined. More than 80 percent of the planet's tremors occur in the circum-Pacific belt, and about six percent of the large, shallow earthquakes are in the Alaska area, where as many as 4,000 earthquake at various depths are detected in a year.

Here are the top 20 states by number of earthquakes, 1974-2003, according to the U.S. Geological Survey:
1. Alaska
2. California
3. Hawaii
4. Nevada
5. Washington
6. Idaho
7. Wyoming
8. Montana
9. Utah
10. Oregon
11. New Mexico
12. Arkansas
13. Arizona
14. Colorado
15. Tennessee
16. Missouri
17. Texas
18. Illinois
19. Oklahoma
20. Maine

Answer 3

The Earth's crust is cracked into large pieces called tectonic plates. The largest of these plates lies under the pacific ocean and the edge of it is known as the ring of fire. Earthquakes occure when these plates try to move. They get stuck on the adjoining plates until something gives and then move releasing energy in the form of an earthquake. This occures near the edges of the plates.

The Western portion of part of the state of California is on the pacific plate. This is the portion west of the San Andraes fault. The San Andraes fault is the eastern border of the pacific plate.

Often times, the edges of plates are cracked in many places and so California has a lot of faults.

Answer 4

California just happens to be lucky enough to fall on a major fault line that has the Pacific Plate on the west side and the North American Plate on the east side of the fault. The meeting points of tectonic plates are the most active eartquake prone areas today. There are no other tectonic plates joining in the rest of the US.

Answer 5

Because that is where the Tectonic plates come together along the California coast and the "mantel" or the earth's crust is the weakest there as it is "newer".

Older portions of the earth crust that lay inland in California are more secure because they have solidified eons ago and you have to understand that the Rockies are a relatively new mountain range! - Totally unlike the Alleghenies!

Answer 6

Because of tectonic action. California resides where 2 tectonic plates meet. So whenever they move away, run into eachother, or go north and south, it causes earthquakes.

Answer 7

Because California is on a fault line where the tetonic plates shift, one day California will fall into the sea.

Answer 8

Because the entire coastal part of the state lies on various fault lines that run up and down the entire west coast.

Answer 9

Because there is so many people in California that it is starting to crack and slide off into the ocean.